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Other Stuff => Archived Manufacturer Circles => AudioKinesis Loudspeakers => Topic started by: Duke on 16 Oct 2013, 09:59 am

Title: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 16 Oct 2013, 09:59 am
At the recent Rocky Mountain Audio Fest, we showed two new speakers, and since the Dream Maker LCS system already has its own thread, I wanted to start this one on the rather radical new Event Horizon 210.

Here's a shot from the show: (http://www.audiocircle.com/image.php?id=88515)

And, here's a shot from my living room: (http://www.audiocircle.com/image.php?id=88514)

That may look like a reflex box with big ports, or an under-sized back-loaded horn, but it is neither.  It's a new type of enclosure design, the Manipulated Vortex Waveguide (MVW), patent pending.  This is the invention of Steve Regier and Tom Ewers of Piper City, Illinois, under the brand name Big E Loudspeakers.   I consider myself extremely fortunate to be involved with these two mad scientists, and their associates, in bringing the MVW into the home audio world. 

Now I cannot prove any of the claims I'm about to make about the behavior of these speakers, so feel free to reject my description as pure marketing or whatever other unflattering term comes to mind.  And my understanding of what these speakers do is still evolving. 

Briefly, inside the box are structures whose dimensions have been carefully manipulated to generate a vortex, one on each side of the box.  These vortices are guided to the outside world through the openings, called "bells", on either side of the cone drivers, in such a way that they cover a fairly wide horizontal arc.   Hence the name of the enclosure type, manipulated vortex waveguide, or MVW for short.

Sound propagates more efficiently on the edge of a vortex than through still air, which why jet engines are so freakin' loud.  In fact, the study of the acoustic properties of a vortex dates back to the early 1950's, when efforts were first being made to understand and reduce the loudness of jet engine exhaust. 

One characteristic of the MVW enclosure was highlighted by their less-than-optimum up-against-the-wall placement there at RMAF, and that is their ability to project a decent soundstage (including a fairly wide sweet spot) with much less than optimum placement.   This is in part due to the SPL falling off a bit more slowly with distance than from a normal point source; over in the PA world, measurements taken have indicated behavior in this regard that looks more like what one would expect from a line source, at least up to a certain point, beyond which they seem to revert to typical point-source-approximating behavior.   In other words, the vortex effect seems to have an event horizon, wiithin which their behavior is somewhat unorthodox.

Another interesting characteristic of the MVW is that it exhibits the opposite of dynamic compression, which I guess we'd call dynamic expansion.   The efficiency actually inreases a bit as we crank up the power - sort of like a ramjet engine is much more efficient at high speed than at low speed.  The result is rather startling dynamic contrast.  The real-world efficiency of an MVW speaker seems to be 2 or 3 dB higher than the calculated efficiency, this based on my comparing MVW prototype speakers side-by-side with conventional speakers of known efficiency. 

And yet another characteristic of the MVW speaker is its lack of cabinet-induced overhang on the tail end of the waveform.  Once the cone stops energizing the vortex, it quenches very quickly.  The result is very good clarity, even in the bass region.  Combined with the dynamic expansion characteristic, we get really good impact - it's a very tight-sounding speaker.   Over in the bass guitar cab world, MVW cabs have been on the market for some time now (built by Mike Arnopol, who some of you may know as Patricia Barber's bass player), and they allow bass players to play 1/8 and even 1/16 notes with good definition, instead of it just turning into a wall of mud.

Now the MVW speaker is not without its idiosyncracies.  In some ways, it behaves more like a musical instrument than like a typical speaker system.   For instance the type of wood used makes a significant difference.   Many different types have been tried, and so far Baltic Birch gives the best results. 

These particular speakers were designed by Steve and Tom, and the enclosures themselves built by Sam Crook of Speaker Hardware.   I am licensed to offer MVW speakers to the high-end home audio world, and my primary role is crossover design.  I feel like the crossover was about 90% done when I took these speakers to RMAF; imo, I still have a bit more tweaking to do. 

The Part-Time Audiophile posted some photos of (and commentary) on the Event Horizon 210 speakers, click here (http://parttimeaudiophile.com/2013/10/15/rmaf-2013-audiokinesis-james-romeyn/) and scroll down a bit.

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JohnR on 16 Oct 2013, 11:10 am
Duke, sorry if I missed it but just to get me thinking on the right track, is there a tweeter/compression driver between the two mids?
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 16 Oct 2013, 11:27 am
Duke, sorry if I missed it but just to get me thinking on the right track, is there a tweeter/compression driver between the two mids?

Yes, there's a compression driver that fires through that slot-like aperture between the mids.   

Crossover between woofer and mids is in the 200-250 Hz ballpark, while the crossover between mids and compression driver is way up around 8 kHz.  Now normally we'd expect side-by-side 6-inch cone mids to beam badly, even if they're slightly cross-firing, if we run them up anywhere near that high.  However such does not seem to be the case.  Rather, it seems that the vortex improves the dispersion in the horizontal plane eyond what we'd normally expect.   The change in tonal balance when walking back and forth in front of the speakers is minor.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JohnR on 16 Oct 2013, 11:32 am
Thank you Duke. I will read and digest.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: playntheblues on 16 Oct 2013, 12:33 pm
Hi Duke, congrats on a great show (RMAF)!  What are the specs on these bad boys?  DB of Eff, 3db down points etc.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Berndt on 16 Oct 2013, 12:45 pm
Not one, but two new designs unveiled?
Youvguys are killing me. How low do they go?
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: playntheblues on 16 Oct 2013, 12:48 pm
I found the eff. in the article....96db
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: konut on 16 Oct 2013, 02:30 pm
Fascinating. A few questions. Is the mid-high cab separate from the bass cab? Do the mid drivers also  benefit from the MVW technology? How do you address the cancellation caused by the cross-firing mids? Any plans for single bass, single mid, tweeter, cab?
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: nullspace on 16 Oct 2013, 03:18 pm
Brief video of the speakers @ RMAF: http://youtu.be/pGgaIeCz7lY (http://youtu.be/pGgaIeCz7lY).

From what I can hear, sounds great Duke -- wish I had made the trip to hear them. Best of luck with the new speakers. What's the impedance look like? Amenable to high-Zo amps? Ballpark price?

Regards,
John
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Berndt on 16 Oct 2013, 06:46 pm
High efficiency, prosound drivers, danley style Crunk .
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 16 Oct 2013, 07:59 pm
Hi Duke, congrats on a great show (RMAF)!  What are the specs on these bad boys?  DB of Eff, 3db down points etc.

I don't have exact specs on the low end, and this isn't a technology that we can model with accuracy yet.  Still too young.   I think the bass response sort of approximates a low-Q sealed box, as far as having a gradual rolloff, but we're able to use higher efficiency woofers than would be suitable for a sealed box.   I'd probably claim ballpark lower 40's/upper 30's, but we played a pipe organ recording that someone brought and, once we turned the volume up a bit, it made the room shudder.  We played part of a kodo drum track and the exhibitor two doors down came into the room to track down the rumble that had permeated his room, at first he thought his subwoofer amp was dying a nasty death and trying to take its woofer with it.  So there is more happening way down low than my claim implies, but the low end isn't apparent until something like that comes along.

The calculated efficiency, based on the woofers' Thiele/Small parameters, is in the 96 dB ballpark.  But the characteristic of the vortex enclosure that causes its efficiency to increase a bit as more power is applied results in a somewhat higher "real world" efficiency.  We probably get an extra 3 dB or so once the vortex generators get hit with some power. 

Not one, but two new designs unveiled?
Youvguys are killing me.

'Bout killed me too!  I hope to never do that again - two new designs at one show, that is.

I didn't give out much in advance on the MVW speaker because frankly I wasn't confident enough in my ability to get it up to audio show level performance.  We had a few hurdles to overcome along the way - it has enormous potential, and in some ways corresponding challenges, given the attention to detail that is called for in the home audio market.

In my opinion, a good home audio speaker has to do two things:  First, it has to do something so well that you can close your eyes and suspend disbelief and get lost in the music.  That something can be timbre, imaging, impact, coherence, clarity, sense of immersion, whatever.   Doesn't have to do them all, but has to nail at least one of them.   And then (this is the hard part), the speaker has to NOT turn around and do something so wrong that it spoils that illusion.  So my primary job is detecting, identifying, engaging, and functionally destroying audibly significant colorations and distortions.
 
I've done some work in the prosound world in bass guitar cabs, and in a live sound setting the bar is not nearly as high as far as minimizing coloration.  A little coloration isn't going to spoil the illusion because there is no "illusion" - it's reality that you're experiencing, and a little coloration is just part of it.   Not that this is anything new of course, but beating a prosound-type speaker into home audio smoothness can be a challenge.  I believe that I have done so with waveguide-style horns, and now my job is to do so with this new type of enclosures.  Fortunately I'm able to work closely with the inventors, who come up with amazing outside-the-box approaches to help me do my job.  It's like I'm struggling to think in freshman algebra, and they're thinking in differential equations without even being aware of it. 

Fascinating. A few questions. Is the mid-high cab separate from the bass cab? Do the mid drivers also  benefit from the MVW technology? How do you address the cancellation caused by the cross-firing mids? Any plans for single bass, single mid, tweeter, cab?

Yes, the mid-high box is just sitting atop the woofer box, connected only by wires.  The crossover is in the base, at the bottom of the wooferbox - the inside of the enclosure itself is too busy for me to shoehorn the crossover into it. 

The mid drivers are indeed also loaded by manipulated vortex waveguide enclosures.  They cover roughly 220 Hz to 8 kHz, so a lot is asked of them.

As to how the design addresses the cancellation caused by the horizontally-spaced cross-firing mids, I don't fully understand.  I have worked with splayed arrays in the past (mostly with fullrange drivers), toed both inward and outward, and always felt they had poor clarity and only so-so radiation pattern. 

That being said, the toe-in does prevent a strong on-axis hot-spot.  Then we have the output of the mids encapsulated by the vortex, to the left and to the right.  The vortex energy, particularly the lower-frequency vortex energy if I understand correctly, acts as a carrier wave and so you have propagation of the shorter-wavelength mids and highs that is guided more by the vortex than by the physical dimensions of the drivers themselves. 

I have experimented with several other, smaller configurations, and will continue to do so.   Most have not had side-by-side drivers, but I find no degradation of the horizontal dispersion from using a side-by-side driver format with this technology.   I know, this is all goes against everything you and I both know about loudspeaker design, so I don't expect you to take it at face value, but just be open to the possibility that there is something going on that is outside the norm.

This is all like weird science fiction, so let me offer an analogy:  Suppose we lived in a world where Helmholtz resonance had not yet been discovered.  We have two types of speaker enclosures:  Sealed boxes, and open baffle dipoles.   Along comes this idiot who cuts a small hole in his sealed box and claims that the result is more powerful bass, when we all know good and well that a hole in a sealed box turns in into a poorly designed dipole, so we know the result is going to be less bass.  And we would be wrong.

So I don't ask you to go so far as to believe any of what I'm saying - just be open to the possibility (http://www.barnesandnoble.com/w/theory-of-vortex-sound-m-s-howe/1100938672?cm_mmc=googlepla-_-textbook_instock_26to75_pt99-_-q000000633-_-9780521012232&cm_mmca2=pla&ean=9780521012232&isbn=9780521012232&r=1).  I'm in a fortunate position at the moment - my and Jim Romeyn's "conventional" (relatively speaking) Dream Maker LCS system was deemed a success by many who heard it, so that gives me a little credibility.  I'd like to cash in on some of that credibiliy by saying that I wouldn't be actively engaged with the Manipulated Vortex Waveguide if I didn't believe that it was doing something special. 

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 16 Oct 2013, 09:24 pm
Brief video of the speakers @ RMAF: http://youtu.be/pGgaIeCz7lY (http://youtu.be/pGgaIeCz7lY).

From what I can hear, sounds great Duke -- wish I had made the trip to hear them. Best of luck with the new speakers. What's the impedance look like? Amenable to high-Zo amps? Ballpark price?

Regards,
John

Thank you, John!  I hadn't seen that video before. 

The impedance is 16 ohms, not perfectly smooth, but then when it's that high, we can live with less than perfect smoothness.  The amp we used was the Atma-Sphere S-30, which does 45 watts into a 16 ohm load, and has an output impedance of about 7 ohms.  Never pushed it all the way during show hours, but we did after the show Saturday evening, when everyone had gone to dinner.  Played that Kodo drum track all the way through, with the meters peaking out, but I didn't hear obvious clipping.  It was thunder.  Made my wife scream three times, and she was white-knuckling it all through the track - she said it lit up her "fight or flight" response.  That's something these speakers do well for some reason - they hook into the limbic system and sound very exciting, conveying that aspect of live music very well.   

Haven't figured out pricing yet, it's a very labor-intensive box filled with expensive parts, and we haven't solved the finish puzzle yet.  The finish you see is a black stain that my wife applied about two days before the show, as we'd run out of time to have the cabinets professionally painted.  I kinda like the look, as much for what it's not as for what it is.  It's a change of pace at least.   For now, let's say eight grand ballpark, but that may only apply to a "utilitarian" finish version.

High efficiency, prosound drivers, danley style Crunk.

Okay, now we're getting into the fun stuff!!  This is a 128 dB ballpark capable speaker.  The designers have pumped 900 watts into it on a Techmaster cut that has strong 22 Hz fundamentals without the woofers farting out.  That was with the drivers wired in parallel for 4 ohms; obviously I went for the OTL-friendly 16 ohm configuration, but either is quite feasible. 

We're used to nice smooth laminar flow of our backwave energy, in a ported box, backloaded horn, or transmission line.   Nothing wrong with that, but it's not the way of the vortex.  Vortex = turbulence, and turbulence = de-correlation.   If the energy coming from the bells was nice and laminar, the speaker wouldn't go down very deep because the path length isn't long enough to support low bass - we'd get cancellation instead of reinforcement down low.  But instead the energy that emerges from the bells is de-correlated, emerging in quasi-random phase, so its net effect is to reinforce the energy off the front of the cone, but not perfectly so.  In practice we get roughly +3 dB from the de-correlated vortex energy, instead of the theoretical +6 dB we'd get from a back-loaded horn at the frequency where its output is in-phase with the front of the cone - but then our back-loaded horn would also have a very deep null where the backwave energy emerges 180 degrees out-of-phase. 

Why doesn't this de-correlated sound from the bells screw up the clarity?   Well, we get our timing cues from the first-arrival sound, and then the de-correlated later-arriving energy is conceptually consistent with what we're doing in the Dream Maker LCS system!  Just as, counter-intuitively, the extra scrambled-up (de-correlated) reverberant energy from the effects speakers in that system actually improves the clarity and three-dimensionality of the presentation, likewise the delayed & de-correlated energy emerging from the bells actually improves the clarity and three-dimensionality of the MVW system.   It's like we're using the inside of the box for our turbulent path-length-induced time delay, rather than taking the long bounce from floor to ceiling.

Okay, so we have the extra energy from the vortex adding to the energy from the front of the cones, and this effect roughly doubles the air-moving capability of the speaker.  Over in the bass guitar world, Mike Arnopol's MVW cabs behave as if they have twice as much displacement (woofer cone area x linear excursion) as they really do.  The woofer I'm using is the Eminence Kappalite 3010LF.  Go calculate what sort of SPL you could expect from four of those babies per side, and that's the ballpark we're in.

Where this technology is really going to dominate is in sound reinforcement.  Leland Crooks of Speaker Hardware is bringing the MVW cab into the PA world.

Since the enclosure isn't relying on resonant characteristics for its low end (as do sealed and especially vented boxes), there is no overhang added to the tail ends of the waveforms.  The result is great clarity, even down through the bass region.  The de-correlation characteristic that I mentioned earlier accomplishes pretty much the same thing that I aim for with my distributed multi-sub Swarm system, which is to get the in-room bass energy combing in quasi-random phase, resulting in a net smoothing effect. 

One listener on Saturday summed up the Event Horizon 210 pretty well I think.  He just said, "That's the live sound".   Yup, that's what it does well. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: MJK on 16 Oct 2013, 09:43 pm
Quote
Sound propagates more efficiently on the edge of a vortex than through still air, which why jet engines are so freakin' loud.  In fact, the study of the acoustic properties of a vortex dates back to the early 1950's, when efforts were first being made to understand and reduce the loudness of jet engine exhaust.

Vortex and fluid flow go together, I get that and remember some of my fluid dynamics from a long time ago. But sound propagation is not net fluid flow, it is just tiny vibrations of air molecules back and forth without any net displacement.

At first glance this reads like some major snake oil. I am not saying the speaker does not sound good or that there is nothing special going on, I am stuggling with the "vortex" as an engineering/physics/acoustics description of what produces this enhanced performance.

Sorry.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Berndt on 16 Oct 2013, 10:46 pm
I am seeing the MVW with a LCS behind it and calling it good.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: *Scotty* on 16 Oct 2013, 11:11 pm
I would be interested in seeing a quasi-anechoic full frequency measurement sweep and an impedance sweep. Bass extension would be documented and the impedance curve in the bass region would tend to indicate at what frequency the system's bass resonance occurs, if there is one.
 It might be something new and measurements would document it.
Scotty
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 16 Oct 2013, 11:19 pm
Vortex and fluid flow go together, I get that and remember some of my fluid dynamics from a long time ago. But sound propagation is not net fluid flow, it is just tiny vibrations of air molecules back and forth without any net displacement.

At first glance this reads like some major snake oil. I am not saying the speaker does not sound good or that there is nothing special going on, I am stuggling with the "vortex" as an engineering/physics/acoustics description of what produces this enhanced performance.

Sorry.

I don't blame your BS detectors for going off, and thank you for being civil about it.  They should go off!!

My description may well have been imprecise and/or incorrect in some ways.  Getting back to the jet engine example, the vortex generated by a jet engine has a profound effect on the sound of that engine well beyond the distance that the swirling vortex itself extends. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: MJK on 17 Oct 2013, 01:19 am
Getting back to the jet engine example, the vortex generated by a jet engine has a profound effect on the sound of that engine well beyond the distance that the swirling vortex itself extends.

OK, but a jet engine has a whole lot of air flowing through and exiting out the exhaust. The air flowing past or over an exhaust structure will produce many vortices. But for a speaker there is no net air flow, just very small air oscillations. Maybe the internals of your speaker enclosure use standing wave resonances very creatively to generate an increase in efficiency and great sound, but I have my doubts about any vortex being created.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 17 Oct 2013, 01:40 am
OK, but a jet engine has a whole lot of air flowing through and exiting out the exhaust. The air flowing past or over an exhaust structure will produce many vortices. But for a speaker there is no net air flow, just very small air oscillations. Maybe the internals of your speaker enclosure use standing wave resonances very creatively to generate an increase in efficiency and great sound, but I have my doubts about any vortex being created.

I don't feel at liberty to comment on details of the internal structure, but that's obviously where any intentional vortex shedding would be happening, and it would be somewhat level-dependent. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 17 Oct 2013, 02:31 am
I am seeing the MVW with a LCS behind it and calling it good.

That is a definite possibility.  Unless we do a major redesign, we'd have to drive the LCS effects speaker with a separate amplifier to get the levels to match up, as there's a considerable efficiency mismatch otherwise.

I would be interested in seeing a quasi-anechoic full frequency measurement sweep and an impedance sweep. Bass extension would be documented and the impedance curve in the bass region would tend to indicate at what frequency the system's bass resonance occurs, if there is one.
 It might be something new and measurements would document it.
Scotty

Last I heard, the frequency response measurement protocol that seemed to work the best was to take a reading outdoors at some distance using full-spectrum pink noise instead of a sine-wave sweep.  That's not something I could easily do, but at some point it will probably happen. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Berndt on 17 Oct 2013, 02:34 am
Duke, I can see why you wanted me to wait now.
Super interesting.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: brj on 17 Oct 2013, 05:15 am
Quote from: Duke
My description may well have been imprecise and/or incorrect in some ways.  Getting back to the jet engine example, the vortex generated by a jet engine has a profound effect on the sound of that engine well beyond the distance that the swirling vortex itself extends.

Much of the noise from a jet or rocket engine results from the shear layer formed at the interface between the exhaust gas and the freestream.  The relative velocity (and pressure, temperature, density, etc.) of each is radically different, and you end up with a vigorous, even violent, free shear flow.  Turbulent, absolutely, but I'd hesitate to imply that any form of stable, coherent vortex exists.  Certainly they don't generate a clean toroidal vortex, ala the classic smoke ring.

If the toroidal vortex is what you're looking to describe, then perhaps a "vortex cannon" would provide a better analogy?  Examples abound, from the student project (http://www.youtube.com/watch?v=4b2SV3ASUxY), to the overly enthusiastic (http://www.youtube.com/watch?v=QrgTtZXuj4w), to the crowd control concepts (http://www.smartplanet.com/blog/thinking-tech/vortex-gun-can-shoot-pepper-spray-at-90-mph/11255).  Though even then, these rely on the center of the air pulse moving faster than the edge so that you "roll up" the toroidal vortex.  This runs a bit counter to the idea of a speaker driver by itself, where you're typically aiming for pure pistonic motion, but it appears that the specific enclosure features handle that aspect for you, much like the "barrels" of the "cannons" shown in the links above.  That said, I'd be curious to know if a driver vibrating at higher frequencies can actually set up a fully formed toroidal vortex even with the help of the cabinet.  It seems most likely at the lowest end of the audio range.

The details of sound travel through such air disturbances, I'll leave for others, though it occurs to me that those studying the aeroacoustics of helicopter rotor blades might have looked at some of this, as a rotating rotor blade on a hovering helicopter would create what is essentially a toroidal vortex as well.

None of this should be taken as criticism of the idea you're working on Duke, and you should absolutely protect the intellectual property you're working so hard to develop.  I think there is just a desire for any naming or description to accurately reflect the science involved.  Marketing efforts have taken so many liberties with legitimate scientific language and principles over the years that I suspect that those in your target market with even the remotest interest in how things work may not hang around long enough to hear your product if the fundamental mechanisms are described in a manner that is perceived as "fake".  This is probably especially true when you're trying to break new scientific ground.  (And yes, it can be painfully challenging to reduce the complex down to a point where those that are interested, but lacking complete background in a field, can absorb and appreciate the details in full.)

I wish that I'd had a chance to hear them, but when I finally made it to your room at the end of the day on Sunday, I was so focused on the LCS system that I obviously gave them short shrift.  I look forward to hearing next year's RMAF incarnation!
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JohnR on 17 Oct 2013, 06:23 am
I don't think Duke can change the name of it as it was invented by those other guys.

Other than that, I'm confused as heck :D

But I'm just really intrigued that there's a new type of enclosure. Who would have thought? Looking forward to reading/learning more about it in future.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Thomas Ewers on 17 Oct 2013, 05:26 pm
Hi Guys I am BigE of BigE Loudspeakers.

We Hope to clarify things a touch.

If you wanted a more conventional name we could have stuck with a ...
Frequency Independent Virtual Compression Labyrinth Horn.

This naming convention however ignores the fact that we actually induce Vortex Shedding intentionally inside the cabinet. The theory of Vortex Sound is actively taught still today and was re-examined after the advent of the Jet engine to explain why it is so dang loud. Upon review of M.S. Howes textbook we found many correlations. It is however a graduate level MATH book. Fun!!! In the book vortex sound does not require a spinning ring like a vortex ring from a Dolphin or Vortex Cannon (While totally cool) it is the study of all non-laminar flow (turbulent flow) and interactions of such.

As for the Frequency independent part we have utilized the same cabinet as both a dual driver 8" sub or cross-fired Coax loaded PA top. Driver seems to tune the cab more than the other way around.. Not to say it is completely independent as the size of the cab can limit extension on top or bottom of the frequency range.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 17 Oct 2013, 06:53 pm
Hi Guys I am BigE of BigE Loudspeakers.

We Hope to clarify things a touch.

If you wanted a more conventional name we could have stuck with a ...
Frequency Independent Virtual Compression Labyrinth Horn.

This naming convention however ignores the fact that we actually induce Vortex Shedding intentionally inside the cabinet. The theory of Vortex Sound is actively taught still today and was re-examined after the advent of the Jet engine to explain why it is so dang loud. Upon review of M.S. Howes textbook we found many correlations. It is however a graduate level MATH book. Fun!!! In the book vortex sound does not require a spinning ring like a vortex ring from a Dolphin or Vortex Cannon (While totally cool) it is the study of all non-laminar flow (turbulent flow) and interactions of such.

As for the Frequency independent part we have utilized the same cabinet as both a dual driver 8" sub or cross-fired Coax loaded PA top. Driver seems to tune the cab more than the other way around.. Not to say it is completely independent as the size of the cab can limit extension on top or bottom of the frequency range.

Thanks for posting, Tom! 

It occurs to me that physical spinning or turbulence of the air itself out beyond the cabinet may not be required for the sound to behave as if it's in a vortex.   The compression driver on a horn comes to mind as an example:  the air itself isn't actually flowing through the phase plug and being compressed - the air molecules are really just moving back-and-forth a small distance - but the sound energy behaves as if that's what's happening, and the result (increased efficiency) extends out well beyond the cabinet itself.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Berndt on 17 Oct 2013, 07:27 pm
Welcome to AC, Thomas!
A friend of Dukes is a great thing.
Look forward to hearing this beast.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 17 Oct 2013, 07:40 pm
None of this should be taken as criticism of the idea you're working on Duke, and you should absolutely protect the intellectual property you're working so hard to develop.  I think there is just a desire for any naming or description to accurately reflect the science involved.  Marketing efforts have taken so many liberties with legitimate scientific language and principles over the years that I suspect that those in your target market with even the remotest interest in how things work may not hang around long enough to hear your product if the fundamental mechanisms are described in a manner that is perceived as "fake".  This is probably especially true when you're trying to break new scientific ground.  (And yes, it can be painfully challenging to reduce the complex down to a point where those that are interested, but lacking complete background in a field, can absorb and appreciate the details in full.)

Thanks for your kind words, Brian.  Hopefully Tom's post has shed some actual light, as he understands this stuff, whereas I'm just winging it from the bits and pieces that have stuck in my mind.  I'm the blind man trying to describe the elephant.

I'd be curious to know if a driver vibrating at higher frequencies can actually set up a fully formed toroidal vortex even with the help of the cabinet.  It seems most likely at the lowest end of the audio range.

To the best of my knowledge you are correct that it's the longer wavelengths that are involved in the vortex shedding.  Fortunately they seem to act as a carrier wave for the shorter wavelengths - and no, I don't begin to understand the mechanism.   But something is making the dispersion wider and more uniform than it should be.   

I don't think Duke can change the name of it as it was invented by those other guys.

Other than that, I'm confused as heck :D

But I'm just really intrigued that there's a new type of enclosure. Who would have thought? Looking forward to reading/learning more about it in future.

I can't begin to tell you how exhilirating it is for me to be involved in this project, even though my technical contributions are in the peripheral area of crossover design.   The implications are pretty big, I think.   Over in the bass cab world where the technology essentially made its battlefield debut, the MVW cabs are totally kicking my butt.  I used to build what were arguably the best boutique bass cabs of their general type, but now I'll have to find a different niche if I'm going to stay competitive over there. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 18 Oct 2013, 11:37 pm
Not one, but two new designs unveiled?
Youvguys are killing me. How low do they go?

I'm sure Duke replied, but in case not...Duke mentioned to me f3 circa 40 Hz and that sounds about right.  Open low E on electric bass and double bass is 41 Hz.

It did seem like Dream Maker LCS went lower.  IIRC boundary reinforcement causes DM LCS Effects Speaker to have slightly lower cutoff (low 30s) than the Main Speaker (mid-high 30s).  (One visitor, after the on-off Effects Speaker demo, thought it was a sub.  It likely does provide a slightly lower bass cutoff, but a lot more than that too.) 

As Duke likely mentions in this thread, I've not heard anything start/stop like this Vortex thingy ever, including many outrageous horns like the Volti Vitora next door.  Scot Hull already reviewed Vitora, then heard it at RM, and said the recent post-Stereophile review (Class A, diminished low bass) improvements are hugely audible.  Vitora sounded absolutely huge, but where I sat far L not even close in neutrality vs. AudioKinesis.  Cupped hands effect too, but extremely broad range/not narrow so you can adapt to that.       

Anyway, back to Vortex...extremely arresting....you can't easily have conversation while they play because the sound is so deep in your head...not just loud.  The sound is as dense as I've ever heard, likely more so.  SPL wise they will crack walls even with the S30 we used.  Duke may disagree, but I thought maybe a couple times the S30 might have run out of juice powering DM LCS, sounded better when I turned it down.  Conversely, Vortex never ever any hint of strain and levels that made me retreat to the alcove in back.

On a side note no apparent long term ear damage from the show thank goodness. 

Hey, did Duke mention he used 16 or 18AWG on the Vortex, about 30', with tiny little alligator leads on the end to make it easier to switch with Dream Maker?

Remarkable sweet and wide image and just incredibly good first impression. 

First meeting with Scot Hull, pro reviewer, Confessions of a Part Time Audiophile.  He first listens to the Vortex, is just slack jawed, he can't fit this into any pre-existing paradigm (he recently reviewed the above mentioned Vitora behemoth horns). 

After the audition, prior to hearing Dream Maker...Scot approaches Duke taking a brief break (probably sleeping while standing up after being so sleep deprived) in the back alcove.  Scot is a big guy, thick black hair and black beard IIRC, has this huge camera and light tree, he looks sternly at Duke and says, as if Duke is in trouble: "Now the first thing is why do those speakers sound so good and image and stage like that pushed up against the wall?  That's not supposed to happen!"   

Scot's as close as a pro reviewer can get to our dear Tyson.  Honestly, I am sure Tyson and Pez have made permanent imprint and changed the entire show review Gestalt.

Vortex: about as consistent in top/down response as I've ever heard.  If there was any irregularity or FR glitch I never caught it.  One does wonder how they sound per Cardas setup, spaced out from the wall.  But the credenza/console begs to be next to the wall. 

The more you hear them the more you want to listen.  Absolutely no fatigue except a couple times it was just a bit loud for me.  They have this immediacy and extreme coherence, kind of like a stat that plays like a horn but better than any prior horn. 

IMO less treble extension vs. DM LCS, but I'm 6-3, maybe better down lower, don't know.  Thing is though you don't really care about that once they start playing. 

Big E licensed Pro bassist Mike Arnopol to make the bass guitar Vortex cabs.  TalkBass forum speaker techs have ripped Mike several new orifices for claims such as maximum output, dynamics increase with input, room loading, speed, start/stop, etc, etc.  I have to agree with Mike: there are two camps, skeptics and those who heard it.  Bass mode wise, I will state categorically, although DM LCS goes about 1/2 octave lower...I'm convinced the Vortex had less modal effects even though DM LCS damps bass modes via six mid bass all with different boundary path lengths and eight ports to close or leave open.   

These Vortex thingys are a new paradigm.  Doesn't matter if they can't explain it properly or if science says LLPOF.  The lap times tell the story.

I liked the Vortex look first time I saw them.  The cabinet is simultaneously 50s retro and modern somehow.  Scot said "They're the ugliest best sounding speakers in the world!"  Owner/proprietor of San Francisco Audio Vision (super high end) Antonio came in twice with a woman.  Second time she had her high end camera phone, she (discreetly) took a lot of images, and he kept nudging her to get more.  I can only imagine he:
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 19 Oct 2013, 12:43 am
OK, but a jet engine has a whole lot of air flowing through and exiting out the exhaust. The air flowing past or over an exhaust structure will produce many vortices. But for a speaker there is no net air flow, just very small air oscillations. Maybe the internals of your speaker enclosure use standing wave resonances very creatively to generate an increase in efficiency and great sound, but I have my doubts about any vortex being created.

Call the Volti Audio guy and ask him what was the sound like in his room Saturday night from our room two rooms over from his.  I've been around dozens or hundreds of so-called ultra high powered floor to ceiling subs, studio experience, Different Fur, Record Plant, others.  Nothing I've ever heard including Infinity IRS III in a pro built sound room had the overall impact of the Event Horizon 210.  Surely, absolutely nothing stops and starts like it.

45W per channel we used.   

EH 210 reminds me of Doc Kupka walking into the Record Plant Control Room warming up his baritone sax. 

   
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: mamba315 on 24 Oct 2013, 05:13 am
Found this (http://forum.bigeloudspeakers.com/t156-mvw-technology-revealed#1013) on the Big E forum posted October 5th.  I know I'm curious how these things work and I'll bet I'm not alone.

"We want to thank the Bass community for being the first to embrace our MVW technology. Now that we have done the legal groundwork to protect our intellectual property the time has come to say "Thank You". In a hat tip to the Bass community Tom and I are preparing to reveal the workings of the MVW technology in an upcoming issue of Bass Gear Magazine. This will be the first public unveiling of the working of our technology - Thanks Bass Players. "

I haven't been in the large local bookstores lately that carry the most magazines, so I don't know if this mag is available locally.  I'll hunt local retail if I have to, but is there an online way to order a single issue?  I live "a bit" outta town these days, so the drive isn't always cherished.

BTW, really fond of the finish on the show speakers.  I know the look was possibly some last-minute serendipity, but it makes a very strong statement to me that fits this new design.  While looking at the pics on PTA, my mind jumped to the popular Hitachi Maxell (http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDQQFjAB&url=http%3A%2F%2Ficonicphotos.wordpress.com%2F2010%2F05%2F31%2Fblown-away-man%2F&ei=fa1oUpL5BcKviAKfl4CwAw&usg=AFQjCNFd8ugHbemEYST7XZXb6I6h-9kMig&sig2=vXAe4NZQnBw_mbwFlVtmUA&bvm=bv.55123115,d.cGE) photo.  Seems like a good match, visually and perhaps sonically as well.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Quiet Earth on 24 Oct 2013, 12:15 pm
http://www.bassgearmag.com/bgm (http://www.bassgearmag.com/bgm)

www.talkbass.com/forum/f15/ (http://www.talkbass.com/forum/f15/)


most recent Big E thread is here : http://www.talkbass.com/forum/f15/big-e-speakers-pt-3-a-1020840/ (http://www.talkbass.com/forum/f15/big-e-speakers-pt-3-a-1020840/)

Older big E threads : http://www.talkbass.com/forum/f15/big-e-speakers-pt-2-a-963685/#post13971248 (http://www.talkbass.com/forum/f15/big-e-speakers-pt-2-a-963685/#post13971248)    and http://www.talkbass.com/forum/f15/big-e-speakers-898299/index53.html (http://www.talkbass.com/forum/f15/big-e-speakers-898299/index53.html)
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 24 Oct 2013, 02:17 pm
http://www.bassgearmag.com/bgm (http://www.bassgearmag.com/bgm)

www.talkbass.com/forum/f15/ (http://www.talkbass.com/forum/f15/)


most recent Big E thread is here : http://www.talkbass.com/forum/f15/big-e-speakers-pt-3-a-1020840/ (http://www.talkbass.com/forum/f15/big-e-speakers-pt-3-a-1020840/)

Older big E threads : http://www.talkbass.com/forum/f15/big-e-speakers-pt-2-a-963685/#post13971248 (http://www.talkbass.com/forum/f15/big-e-speakers-pt-2-a-963685/#post13971248)    and http://www.talkbass.com/forum/f15/big-e-speakers-898299/index53.html (http://www.talkbass.com/forum/f15/big-e-speakers-898299/index53.html)

Quiet Earth,
Thanks for posting the links!

I found no Big E connection in the top two links.  The Talk Bass links worked, and I subscribed to Part 3.  Looks like Mike stirred up quite the hornet's nest with his MVW cabinets for bass guitar and amplified double bass.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Tyson on 24 Oct 2013, 04:23 pm
I wish I'd had a chance to hear them.  For reference, the GR Research Open Baffle Servo Subs are my current standard for what bass can be.  It's on a different playing field entirely from anything else I've ever heard.  But reading this thread makes me thing the EH-210 might be a real challenger.

Has anyone considered making it in a bigger cab and tuned a bit lower to make it into a true subwoofer for use with regular "main speakers"?  Seems like these would make nice "stands" for a small bookshelf speaker, or even a large bookshelf speaker like Geddes stuff that doesn't do real bass, but does great mids/highs.   
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 24 Oct 2013, 05:36 pm
Found this (http://forum.bigeloudspeakers.com/t156-mvw-technology-revealed#1013) on the Big E forum posted October 5th.  I know I'm curious how these things work and I'll bet I'm not alone.

"We want to thank the Bass community for being the first to embrace our MVW technology. Now that we have done the legal groundwork to protect our intellectual property the time has come to say "Thank You". In a hat tip to the Bass community Tom and I are preparing to reveal the workings of the MVW technology in an upcoming issue of Bass Gear Magazine. This will be the first public unveiling of the working of our technology - Thanks Bass Players. "

I haven't been in the large local bookstores lately that carry the most magazines, so I don't know if this mag is available locally.  I'll hunt local retail if I have to, but is there an online way to order a single issue?  I live "a bit" outta town these days, so the drive isn't always cherished.

BTW, really fond of the finish on the show speakers.  I know the look was possibly some last-minute serendipity, but it makes a very strong statement to me that fits this new design.  While looking at the pics on PTA, my mind jumped to the popular Hitachi Maxell (http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDQQFjAB&url=http%3A%2F%2Ficonicphotos.wordpress.com%2F2010%2F05%2F31%2Fblown-away-man%2F&ei=fa1oUpL5BcKviAKfl4CwAw&usg=AFQjCNFd8ugHbemEYST7XZXb6I6h-9kMig&sig2=vXAe4NZQnBw_mbwFlVtmUA&bvm=bv.55123115,d.cGE) photo.  Seems like a good match, visually and perhaps sonically as well.

Thanks!

The Bass Gear article will be coming out some time shortly after January 2014, so it'll be a little while yet.

I wish I'd had a chance to hear them.  For reference, the GR Research Open Baffle Servo Subs are my current standard for what bass can be.  It's on a different playing field entirely from anything else I've ever heard.  But reading this thread makes me thing the EH-210 might be a real challenger.

Has anyone considered making it in a bigger cab and tuned a bit lower to make it into a true subwoofer for use with regular "main speakers"?  Seems like these would make nice "stands" for a small bookshelf speaker, or even a large bookshelf speaker like Geddes stuff that doesn't do real bass, but does great mids/highs.

I haven't used an MVW box in pure subwoofer mode yet myself, but did hear a subwoofer version in a home theater system last year.    The cabinet shape itself is not very flexible, in contrast with a sealed or vented box.  The cabinet isn't tuned in the sense that one tunes a vented box; it's more like a particular size driver calls for a particular set of dimensions (internal and external) for the cab.  There is a bit of leeway, with low-frequency extension predictably improving as the box grows in size, but only up to a point.   Nor does it perform as well with a vertical orientation, so I'm not sure how well it would work as a stand... but it would certaily work as a sub.   The same enclosure can be used for either a wideband woofer or for a subwoofer; in other words, the characteristics of the speaker itself are the dominant factor in low-end extension, assuming corners haven't been cut in the box design.

But the technology does the "slam" thing very well, so a subwoofer system is a logical step at some point.  Thanks for your ideas! 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Thomas Ewers on 24 Oct 2013, 05:50 pm
Has anyone considered making it in a bigger cab and tuned a bit lower to make it into a true subwoofer for use with regular "main speakers"?  Seems like these would make nice "stands" for a small bookshelf speaker, or even a large bookshelf speaker like Geddes stuff that doesn't do real bass, but does great mids/highs.

Yes we have up to 21" subs functioning already. We have a night club running on two of our 218SLVX iterations that is a Double 18 in a box about 56" IIRC Wide. They Thump and at war volume start making the dance floor feel like liquefaction. . The 21s will easily go infrasonic. But a single 21 is about 48"x40"x26" or so in Lil'E configuration which is like a huge version of just one side of the top down firing. Pics on our website.

A well tuned RachE 12 with a Lab12 Driver should be able to get down Infrasonic as well and make a darn good HT sub.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Thomas Ewers on 25 Oct 2013, 02:26 am
I haven't been in the large local bookstores lately that carry the most magazines, so I don't know if this mag is available locally.  I'll hunt local retail if I have to, but is there an online way to order a single issue?  I live "a bit" outta town these days, so the drive isn't always cherished.

I believe you can order them online and you can definitely view it online.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: mamba315 on 28 Nov 2013, 05:44 am
Anything new here to report?  When is their estimated release?
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 28 Nov 2013, 10:43 am
Anything new here to report?  When is their estimated release?

Well, the first order for a pair of Event Horizon 210s was place a little over a week ago.  They're going in a very large living room.  Some custom woodwork is involved and the build will probably take a while, but I'll post pictures when they are finished.   

In addition to the large three-way Event Horizon 210, there is a medium-sized two-way under development.   

The pair that we showed at RMAF is theoretically available... I say "theoretically" because my wife has started referring to them as her speakers. 

The mid/tweet module (top part) of the pair destined for the large living room will differ somewhat from the mid/tweet module that we showed at RMAF because we're going with a physically very large compression driver that has a beryllium diaphragm.  In the past I have shied away from ubertweeters, because I've heard far too many speakers with amazing ubertweeters where the mid/woofer section was clearly outclassed.  So despite how nice the top end was, I found myself unable to relax into enjoying the music because the disparity was constantly making itself known.  Well, the manipulated vortex weveguide is imo capable of keeping up with an ubertweeter, and I wanted one that would have no dynamic limitations for all practical purposes, so we went with a beryllium-diaphragm compression driver.   This will of course be available as an option, but note that retail on the driver is $1100/pair. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Berndt on 3 Dec 2013, 10:28 pm
I keep thinking I am looking at my next set of speakers.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 13 Dec 2013, 01:15 pm

A well tuned RachE 12 with a Lab12 Driver should be able to get down Infrasonic as well and make a darn good HT sub.

I'm late to the party but thought I'd chime in.  I am the prosound, ht, and middle home audio segment of the MVW world.  I completed last week the sub Tom refers to above.  It's a modification of the prosound subs designed for maximum extension rather than maximum output.  Stunning is the description.  Effortless and transparent.  Not usually adjectives I'd use to describe a sub.  Deep enough to rattle your insides, it goes infrasonic easily.  The transition from it to the tops was invisible. 

It's part of a prototype system going to a high end shop for evaluation. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: mamba315 on 14 Dec 2013, 07:46 pm
So, would this sub be good in a "swarm" config with Dukes upcoming 2-way?
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Berndt on 14 Dec 2013, 07:57 pm
Tantalizing adjectives.
With baited breath.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 14 Dec 2013, 09:30 pm
So, would this sub be good in a "swarm" config with Dukes upcoming 2-way?

My understanding and listening experience seems to confirm that MVW has at least three unique desirable features: unequivocally highest SPL per enclosure volume (by huge margin, my understanding is no one who auditioned MVW at high levels would contest this), dynamic range rises with increasing SPL (inverse of otherwise universal thermal compression), and a large dose of natural bass mode damping effect. 

Again, Dream Maker enjoys considerable bass mode damping effect via six different active drivers and eight ports.  That's a sum total fourteen bass sources each with disparate path length to room boundaries (plus each port can be either open or air-tight sealed).  Conversely, EV210 has effectively only two active bass sources (because each channel's dual 10s are tightly spaced) plus the vortex openings (unknown number). 

I'm convinced, when we switched from DM to EV210, the latter had more linear bass/less modal effects.  I am 100% supporter of Distributed Array.  But I also think the MVW approximates the linearity of a Distributed Bass Array more than any other architecture (except for possibly a Dual Bass Array, which in theory looks ideal but costs far more than a Distributed Array, requires eight subs in semi-permanent wall installation above the floor, and lacks the other ideal qualities of MVW).

The above, coupled with considerable minimum enclosure volume resulting from the vortex design, seems to minimize benefits of the Distributed Array when employing MVW. 

That said, I'm first in line to help setup and audition a Distributed Sub Array with four MWV subs in a sound room with suitable floor space!       
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Russell Dawkins on 14 Dec 2013, 11:17 pm

 ....dynamic range rises with increasing SPL (inverse of otherwise universal thermal compression)....   
   

This characteristic alone has me completely baffled and curious.   :scratch:

I wonder if, when playing back a completely uncompressed recording of an orchestra, does this mean that the dynamic range produced would exceed that of the original source? If so, I would not want that. Are these aimed instead at dynamically expanding over - compressed pop music?
It seems to me that if dynamic expansion is taking place, then it might "work" for some recordings and at specific levels, but that would depend on the nature of the compression employed in the record production.

I don't want my playback system to interpret the signal–I just want the straight goods.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 15 Dec 2013, 12:26 am
This characteristic alone has me completely baffled and curious.   :scratch:

I wonder if, when playing back a completely uncompressed recording of an orchestra, does this mean that the dynamic range produced would exceed that of the original source? If so, I would not want that. Are these aimed instead at dynamically expanding over - compressed pop music?
It seems to me that if dynamic expansion is taking place, then it might "work" for some recordings and at specific levels, but that would depend on the nature of the compression employed in the record production.

I don't want my playback system to interpret the signal–I just want the straight goods.

Yes, that makes sense. 

I suppose one would decide between two distortions as level increases: thermal compression or expanding dynamics.   

Also, one might prefer the SPL "sweet spot" of standard bass loading vs. MWV.   

From my three day exposure, I think I prefer the dynamic distortion of the MVW vs. standard bass loading.  I could see how/why a recording engineer might prefer the latter.     
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 15 Dec 2013, 02:23 pm
As has been the case so many times with this technology, many of the standard adjectives don't really reveal what we hear.  James is correct with the dynamic expansion, but only because it's the closest terminology we have.  What happens is as you increase the power to the cabs the vortex field expands.  It feels and sounds like sensitivity is increasing, which it does to a degree. 

In the PA world because we're covering such large area you can walk the sound field and hear the "event horizon".  In the space of about 2 ft you'll hear a sudden dropoff in the output.  It doesn't measure as a big change, 2-3db, but it's very apparent.  It's where the reverberant vortex field suddenly becomes a standard sound field.  It's not there with the home audio boxes, you have the vortex field virtually all the time, covering the entire area. 

It's incredibly useful for PA use.  You can mitigate the spill to unwanted areas by controlling the power.  A show I did last summer outdoors with 4 WT8's per side (2x8 PA Cab) 4 RachÉ18 subs dropped the event horizon about 300ft from the mains.  Perfect, right at the edge of the street, keeping the neighbors happier. 

Two of the home audio subs I think would be more than enough for virtually an installation.  They just don't interact with room modes the same as a standard direct radiator box.  I can get dead even coverage in a high school gymnasium with 2.  And those places are modal nightmares. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 15 Dec 2013, 05:16 pm
I appreciate others such as Leland chiming in because MVW is difficult to explain.  To repeat what musicians said after hearing Mike Arnopol's MVW cabs for bass instruments: "There's skeptics and those who've heard it."  Duke first mentioned this technology to me several months ago.  I did not really grasp it very well with words.  Finally the day prior to setup for RMAF I arrived to pickup Dream Maker LCS and saw EH210 for the first time stacked up in Duke's entry hall way.  Wow, those are pretty cool, me thinks.  Kind of an industrial garage Leave It To Beaver era, retro chic Gestalt.  Interesting.  If you're old enough, think of furniture in glossy magazines around the time Master Soichiro Honda landed his Honda Super Cub 50 on these shores (while you're at it, you'll not find a more interesting success story than that of Soichiro, who started with better pistons and piston rings, delivered by family members on their bicycles, wrapped in bags in handlebar racks...then his fast growing industry decimated by war, and starting from scratch again...).   

The first time you hear MVW you just know, wow, whatever on earth I'm hearing it's unlike anything prior.  No matter what you might think you absolutely have no prior paradigm in which to fit these.

I definitely get the feeling, once tested for THD, these will stand atop the pyramid for quite a long time.  I wonder if anyone else might agree with this: It's like ultra-low distortion ultra-high output headphones, but with all the more pleasurable effects of listening to speakers properly setup in a well treated room.  But it's actually better than that.           
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 16 Dec 2013, 02:01 pm
It's like ultra-low distortion ultra-high output headphones, but with all the more pleasurable effects of listening to speakers properly setup in a well treated room.  But it's actually better than that.           

That is it exactly.  I've been saying it's like wearing headphones since I first heard them a couple of years ago.  I coined the phrase "Intimate Power" to describe it.   That's the tagline for my line of home audio, a tad more plebian than Duke's killer Event Horizons. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Russell Dawkins on 16 Dec 2013, 07:44 pm
I would certainly jump at the chance to hear these. Anything fundamentally new always intrigues me.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: atmasphere on 16 Dec 2013, 10:33 pm
BTW Duke's room sounded really nice this year and it was good to have him and his lovely wife back at the show.

I was not expecting what this speaker did! It seemed very easy to drive, much more so than its appearance suggests. Imagining was first-rate. I found the speaker to be quite musical and a bit disarming, given its small size.

Any plans of a larger model??  :)
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: avahifi on 16 Dec 2013, 11:07 pm
Quote
Now the MVW speaker is not without its idiosyncracies.  In some ways, it behaves more like a musical instrument than like a typical speaker system.   For instance the type of wood used makes a significant difference.   Many different types have been tried, and so far Baltic Birch gives the best results.

This comment raises a red flag for me.  I thought the only part of a loudspeaker system that should contribute to the acoustic output is the driven elements themselves and necessary manipulation of the air.  When some other hopefully inert part is making a sonic contribution, that can only be some spurious resonance in the structure.  Changing wood types should have no effect unless this is changing the basic stability of the cabinet structure.  My vote for an ideal cabinet would be solid concrete bonded and wrapped in lead.  Not very practical, but I want no sound from my speaker cabinet at all.

Frank Van Alstine
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Quiet Earth on 17 Dec 2013, 12:45 am
I thought the only part of a loudspeaker system that should contribute to the acoustic output is the driven elements themselves

This is a common mistake in my very humble and unpopular opinion. A great sounding speaker does not always have to be made this way. I don't know why the cabinet (or room) is not allowed to contribute to the overall sound. This is a silly rule that needs debunking.

No disrespect to Frank or anyone else is intended in my comment. I just see this misguided statement made over and over and over. I think that's why so many acoustically inert speakers sound dull, lifeless, and boring. Again, it is just my observation over many years of trying to be a good listener.

Hope this vortex things works out. I would love to hear it some day. Good luck with it.  :thumb:
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: *Scotty* on 17 Dec 2013, 01:14 am
I also have vote for as accurate as possible acoustic analogue of the electrical signal fed into the loudspeaker. If the intent is to accurately reproduce the incoming electrical signal, structural cabinet resonances approaching the same levels as the THD and IM that drivers themselves produce can only be viewed as an additional source of signal distortion.
 The room on the other hand, will always have a contribution to make to the sound we hear from our stereo systems, all we can do is attempt to manipulate it to our advantage.
Scotty
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 19 Dec 2013, 12:54 pm
MVW speakers bend the rules.  Or at least seem to create new ones.  One of those is the wood.  I believe the difference is the surface density of the wood.  The bass cabs are mostly done from poplar and Okume, for light weight.  It creates a slightly darker tone.  If you compare the surfaces of those vs baltic birch you'll see they are a much more open grain structure.  BB is so close it just about won't take stain.  These cabs are incredibly sensitive to teeny variations in layout, bracing, and the wood used.  They're not easy to build.  Back pressures are very high.  There's no cabinet resonances structurally, that's for sure.  The upper mids seem to be absorbed by the more open grain.  It all has to do with the vortex interaction in the cabinet. 

A/C plywood won't stand up to the pressures.  It has voids, and MVW cabs will find it.  We've blown plys apart in the subs. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: MaxCast on 19 Dec 2013, 01:22 pm
Quote
We've blown plys apart in the subs.
He he he, I want see it.   :D
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 25 Dec 2013, 10:39 pm
BTW Duke's room sounded really nice this year and it was good to have him and his lovely wife back at the show.

I was not expecting what this speaker did! It seemed very easy to drive, much more so than its appearance suggests. Imagining was first-rate. I found the speaker to be quite musical and a bit disarming, given its small size.

Any plans of a larger model??  :)

Thank you, Ralph!

Yes there is something a bit larger in the works, as well as something a bit smaller. 

This comment [the wood makes a difference] raies a red flag for me.  I thought the only part of a loudspeaker system that should contribute to the acoustic output is the driven elements themselves and necessary manipulation of the air.  When some other hopefully inert part is making a sonic contribution, that can only be some spurious resonance in the structure.  Changing wood types should have no effect unless this is changing the basic stability of the cabinet structure.  My vote for an ideal cabinet would be solid concrete bonded and wrapped in lead.  Not very practical, but I want no sound from my speaker cabinet at all.

Frank Van Alstine

Philosophically I agree with you, that the cabinet should be sonically inert, and don't blame you for your skepticism of a design where the type and quality of the wood is critical.  But the big picture is, what gives the best overall results?  This design has some extremely high internal pressures, and if those high pressures aren't dealt with by using high quality plywood and aggressive bracing, then performance suffers unacceptably.  But if we effectively deal with the design's idiosyncracies, imo we end up with some very worthwhile benefits. 

And if the whole idea is still just too unorthodox for you, I still do conventional cabinets.   
 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Russell Dawkins on 25 Dec 2013, 11:13 pm
Merry Christmas, Duke! :xmas:
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: mamba315 on 28 Dec 2013, 07:49 am
Something bigger.. Same top w/ bigger sub(s)?

Will the smaller 2 way be mainly designed to run solo, or with sub support?

Some version of this technology is definitely my next speaker purchase or two.  The way these (are purported to) spread sound evenly throughout a room is a big deal to me.  Who wants to sit in the sweet spot all the time?
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 31 Dec 2013, 03:24 pm
Duke and I have split up the home audio world.  He handles the high end, I do the middle and entry level.  The smaller system can be run with or without subs.  The GC25H upon which it's based is good to 40hz.  I highly recommend it with the RachÉ12 sub though.  Cross at about 60hz.  The RachÉ12 sub with it's chosen driver for home audio is the best I've ever heard.  Seamless into the GC25h's, and utterly transparent. 

It's not in the Event Horizon range in absolute bottom end, but then again I'm not sure what else is.   8)
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Vlad on 27 Feb 2014, 01:08 am
Hi Duke,

Any update on the MVW speakers? I am interested in the smaller 2-way you mentioned before.

Thanks,
Vlad
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 27 Feb 2014, 06:06 am
Hi Duke,

Any update on the MVW speakers? I am interested in the smaller 2-way you mentioned before.

Thanks,
Vlad

Hi Vlad,

The smaller two-way is in the refinement stage of development.  Unfortunately that is very time-intensive for the enclosure designers because it means building test enclosures and/or modifying existing ones.  I'm not at all qualified to do the actual cabinet design on these - that is done by the inventors.  I will do the crossover design when they are done with their work.

The direction of the two-way version changed several weeks ago.   I worked on the crossover design for a two-way bass cab that uses four 6.5" woofers, and I was so encouraged by its performance that I asked the inventors to let me shift directions and do a home audio version thereof for this two-way project.  They agreed, and that is what is in the refinement stage right now.

My version will have different drivers and probably a slightly-to-somewhat different enclosure (depends on which direction the refining process goes), but it will retain the sort of impact that is dominating the high-end bass guitar cabinet world (in that market I compete against this technology, and so I get to see it from a competitor's standpoint as well, and it has superior low-end extension AND pitch definition AND dynamic impact relative to my cabs). 

So this project is definitely moving forward, but I can't yet project a date.

Duke
Title: Re: The Manipulated Vortex Waveguide speaker
Post by: JICRO on 20 Mar 2014, 07:36 pm
Hello Everyone,

For the readers here that would like to know more about what is under the hood in the MVW systems the patent application was published at the USPTO this month as US 2014/0060959. 

Anyone that would like a copy of the patent application, just let me know and I'll send you a copy.
(http://www.audiocircle.com/image.php?id=96640)


All the best,

- Jim Croft


Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 20 Mar 2014, 10:22 pm
Hi Jim,

Good to hear from you!  I always enjoy your patent reviews in Voice Coil.  Thanks for posting this information, I was not aware of it, and for your offer to make a copy available to people. 

If anyone would like, here's a direct link to the patent application on the USPTO site:

http://www.google.com/patents/US20140060959

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: MJK on 20 Mar 2014, 10:41 pm
My opinion.

Looks like a complicated folded transmission line speaker. Interesting design but not new physics. Manipulated Vortex Waveguide appears to be nothing more than clever marketing lingo.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 21 Mar 2014, 12:07 am
My opinion.

Looks like a complicated folded transmission line speaker.

Yes, it does.   My first thought was that it not only looks like a complicated folded transmission line speaker, but a poorly designed one at that. 

My opinion...

Interesting design but not new physics.

Not until you take into account vortex shedding, and I don't know of a mathematical model for doing so, and as a result the design work is dominated by educated guesswork and trial & error at this point.  (I don't do any of the actual design work; Steve and Tom may use mathematical models that I'm unaware of.)

My opinion...

Manipulated Vortex Waveguide appears to be nothing more than clever marketing lingo.

It's both accurate and clever.   

One person might use the term Mass Loaded Transmission Line, and another person might say "Mass Loaded Transmission Line appears to be nothing more than clever marketing lingo."  The second person would be overlooking significant refinements that are not obvious. 

In my opinion, the MVW is a bigger advance over the transmission line than the MLTL is over a ported box. 

(In case anyone is wondering why I chose that example, it's because MJK is the inventor of the Mass Loaded Transmission Line.)
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: MJK on 21 Mar 2014, 01:44 am
Quote
One person might use the term Mass Loaded Transmission Line, and another person might say "Mass Loaded Transmission Line appears to be nothing more than clever marketing lingo."  The second person would be overlooking significant refinements that are not obvious.

ML TL  and the original ML TQWT are two catchy phrases I coined after mathematically modeling these tall ported cabinet designs. The designs had been round for many years without an accurate computer model for DIYers to use during the design phase, simple lumped parameter bass reflex models were not accurate. I invented nothing other then a neat catch phrase that was based on the physical behavior of the air in the enclosure, to be honest I threw it out there onto the Internet tongue in cheek and to my surprise it stuck and seemed to be generally accepted. Understanding the physics and putting together a computer model allowed many DIYers to design these tall cabinets, build them, and then measure the electrical impedance and SPL curves to find that what they had built performed as expected. No more trial and error designs, the loop is closed and the methods proved out. The physics are completely understood.

Quote
Not until you take into account vortex shedding, and I don't know of a mathematical model for doing so, and as a result the design work is dominated by educated guesswork and trial & error at this point.  (I don't do any of the actual design work; Steve and Tom may use mathematical models that I'm unaware of.)

So there is no mathematical model to predict vortex shedding, yet the claim is that this is the source for superior performance. I am not disputing the superior performance, if you say they sound great I trust your ears.

Over the past 15 years I have reverse engineered many different folded passage speakers (probably many 100's), some similar to the pictures in the patent (look at the old Lowther back loaded horn designs for example), once independent impedance and SPL measurements are presented in an independent review and a picture of the cross-section is shown that I can scale. If the picture and measured data is accurate then my TL based model predictions usually are very close. Based on this experience with TL models and looking at the pictures in the patent, I believe this enclosure is nothing more then a very creative TL application that may produce excellent bass output due to complicated standing waves generated by the unique geometry. The behavior of the air in the enclosure can only be accurately predicted by computer models. My TL experience tells me that there is no such thing as a "manipulated vortex waveguide", sorry. When there is enough independent information and measurements available I will probably reverse engineer this design and figure out how it works and if it can be improved, it should be a very interesting intellectual challenge.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 21 Mar 2014, 03:46 am
So there is no mathematical model to predict vortex shedding, yet the claim is that this is the source for superior performance.

What I should have said is:  None of the loudspeaker models that I'm aware of take vortex shedding into account. 

I'm pretty sure that vortex shedding can be modeled, along with its acoustic implications.   The previously mentioned graduate-level text "Vortex Theory of Sound" by M.S. Howe goes over my head almost immediately, but the first paragraph is within my grasp:

"Vortex sound is the sound produced as a by-product of unsteady fluid motions. It is part of the more general subject of aerodynamic sound. The modern theory of aerodynamic sound was pioneered by James Lighthill in the early 1950's. Lighthill (1952) wanted to understand the mechanisms of noise generation by the jet engines of new passenger jet aircraft that were then about to enter service. However, it is now widely recognized that any mechanism that produces sound can actually be formulated as a problem of aerodynamic sound. Thus, apart from the high speed turbulent jet - which may be regarded as a distribution of intense turbulence velocity fluctuations that generate sound by converting a tiny fraction of the jet rotational kinetic energy into the longitudinal waves that generate sound - colliding solid bodies, aeroengine rotor blades, vibrating surfaces, complex fluid-structure interactions in the larynx (responsible for speech), musical instruments, conventional loudspeakers, crackling paper, combustion and combustion instabilities in rockets, and so forth all fall within the theory of aerodynamic sound in its broadest sense."

Distilling down that first paragraph a bit:

 "...any mechanism that produces sound can actually be formulated as a problem of aerodynamic sound. Thus... complex fluid-structure interactions in the larynx (responsible for speech), musical instruments, conventional loudspeakers, crackling paper, combustion and combustion instabilities in rockets, and so forth all fall within the theory of aerodynamic sound in its broadest sense." [emphasis in the original text]

Point being, the aerodynamic theory of sound, a subdivision of which is the vortex theory of sound, is a more general and all-encompassing theory of sound generation than are the loudspeaker models we are accustomed to.   So in a sense the inventors have unplugged from conventional loudspeaker models, gone up a level, and plugged back in, using loudspeaker motors & cones to generate the initiating energy.

I am not disputing the superior performance, if you say they sound great I trust your ears.

Thank you for the vote of confidence, in my ears if not in my grasp of acoustic science!  I'll take whatever I can get!!

Based on this experience with TL models and looking at the pictures in the patent, I believe this enclosure is nothing more then a very creative TL application that may produce excellent bass output due to complicated standing waves generated by the unique geometry.

One of the issues I ran into with transmission lines was cancellation at the frequency where the line length is equal to one wavelength, as at that frequency the energy from the terminus is 180 degrees out-of-phase with the energy coming from the front of the cone.  Various techniques can be used to mitigate this cancellation dip, but none of the ones I'm aware of are obviously applied in any of the MVW designs shown in the patent.  So if the enclosures were transmission lines, I think we'd expect to see that cancellation dip in the measured response. 

I haven't seen anything like the one-wavelength cancellation dip in my own measurements of MVW enclosures.   Now maybe that's for reasons other than the ones the inventors claim, but in watching them follow their vortex paradigm, I've seen them make improvements that I do not think would be predicted by any loudspeaker model I'm aware of.  That being said I certainly do not hold myself out as an expert on loudspeaker modeling.  But if the inventors' paradigm is useful in predicting (though not yet precisely modeling) performance of the MVW loudspeaker, whereas to the best of my knowledge other paradigms are not, then for now at least I'm subscribing to theirs. 

Anyway I don't blame you one bit for being skeptical; if I were in your position, I would be to the extreme.  The most I could ask of you or any other skeptic would be to not indulge in contempt before investigation.   
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: *Scotty* on 21 Mar 2014, 07:01 am
Here are some links to fluid dynamics modeling programs which could be used to analyze what is happening in the loudspeaker.
Open source freeware
http://www.openfoam.com/

http://www.macworld.com/article/1024399/tetruss.html
"TetrUSS is used in aerodynamics and fluid dynamics analysis, and has been used on major projects including High Speed Research / High Speed Civil Transport, Hyper-X, Abrupt Wing Stall, Mars Scout, Joint Strike Fighter and more. What's more, the software has been used in the civilian aerospace industry, academy, automotive, biomedical and civil engineering fields.

NASA research scientists and the Air Force Research Laboratory developed TetrUSS for their own use, and it has evolved into an unstructured-grid flow analysis and design Computation Fluid Dynamic (CFD) software system. It's available free of charge to U.S. entities, citizens and permanent residents. A free training course is even available at NASA Langley Research Center, as well."

Also fluid dynamics for your iPad
http://www.algorizk.com/
Navier Stokes equations
https://itunes.apple.com/nl/app/fluid-dynamics/id382274493?mt=8

Check iTunes for the apps
Scotty
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 21 Mar 2014, 08:06 pm
Scotty is the real deal.  I can't believe how cool is some of the stuff I've learned from his posts.  His range of references is huge, useful, and informative.  The post above is more of the same.  I'm interested in his observations re. MVW, both regarding the math (as he learns about it) and audition if/when he hears it. 

Scotty, you might consider joining Talk Bass toward finding someone local employing Mike Arnopol's MVW Bass Cabinets.  An ideal audition would include A-B test with same "head" amp, MVW cabinet vs. non-MVW cabinet.  5-string bass lowest string is most often tuned to low B, 31 Hz fundamental (though the first harmonic is higher in output vs. the fundamental).  Mike reports MVW is the only system capable of reproducing 16th-note open low B with clarity of each transient.   

Sorry to repeat Mike's adage again, but there appear to be two MVW groups, skeptics and those who heard it.

The same year, maybe late 80s, I heard at The Riviera in Las Vegas CES, both the Duntech Sovereign and hugest flagship IMF Transmission Line speaker.  Both were audio high marks for me, leaving deep impression.  Looking back on it, the IMF transmission line may have offered considerable mode damping effect.  A few years later, Allen Perkins' (Immedia) short-lived (possibly never in production) transmission line/ribbon speaker also had a special quality of bass linearity.     
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 21 Mar 2014, 09:54 pm
Hi Jim,

Good to hear from you!  I always enjoy your patent reviews in Voice Coil.  Thanks for posting this information, I was not aware of it, and for your offer to make a copy available to people. 

If anyone would like, here's a direct link to the patent application on the USPTO site:

http://www.google.com/patents/US20140060959

Hello Duke,

Thank you for your kind words...It is good to know that you enjoy the patent reviews.

I came back to make a short reply for now, and see that the discussion is off and running.

I must say that I can relate to MJK's response to the presentation of the MVW system.

It is unfortunate that the inventors choose to use language that obfuscates the understanding of the functionality of the enclosure topology.  If they truly wish to have others in the field of loudspeakers/acoustics understand and support their concept, then it would be much more effective if they either created a definition of terms, or drew linkages between their terminology and concepts that are more commonly referenced in the field.

In looking back over nearly a hundred years of loudspeaker history, I have yet to see any advancement that could not be reduced to simple terms and analogies to allow better understanding.

While I will attempt to keep an open mind, historically, I have found the use of terms that are new, exotic, or from another field or narrow aspect the field being discussed, the out come usually exposes one of a few things, such as;

   A marketing device, meant to impress the naive and befuddle the well informed, or, reference to criteria that do create real effects, but those effects are so small, or out of band, as to be audibly insignificant.

I have a number of comments about the design concept, which I will try to get around to posting after today.

For now, I must say that after a first pass read of the patent, one is immediately disappointed in the lack of useful disclosure.

The patent system was originally set up with the basic premise that the government will offer a substantial monopoly on an invention for 17 years from the grant date (now, since 1995, 20 years from the filing date) in exchange for the inventor teaching the public enough reduction to practice information that one skilled in the art would be able to build a ‘best mode’ version of the invention.

In the patent there are no specifications, dimensions, references to T/S parameters and their relationship to the architecture, no relational dimensions of the different chamber sections, nothing whatsoever that would teach one how to create a reasonably functioning unit, let alone an optimized device.   

Also, there are no measurements disclosed and no comparative benchmarks illustrated.

This combined with the manner in which the system has been discussed by the practitioners and fans, does nothing to minimize one’s skepticism.

I realize that a good demonstration has been achieved, and those that heard it were impressed, but anyone experienced in the industry knows that the number of external variables involved in show demonstrations is enormous.

That said, I will keep an open mind and pursue further analysis.  Frankly, the main reason for doing so is based on my respect for your (Duke’s) understanding of which parameters impact loudspeaker sound quality and the assumption that he has studied the concept adequately to have uncovered some achievement that cannot be duplicated, or approached, with prior art technology.

At least, it is always entertaining to have a new item that generates excitement by tapping into that part of us that wants to believe there is something that can come along and transcend anything we have experienced before.

It could happen…

All the best,

- Jim
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: genjamon on 21 Mar 2014, 10:28 pm
Jim! Classy post! Much appreciated  :thumb:

I'm not technically literate in loudspeaker design, but interested in these designs and hoping the dialogue remains productive among those of you with expertise.  :)
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: DS-21 on 22 Mar 2014, 05:55 pm
Anyway I don't blame you one bit for being skeptical; if I were in your position, I would be to the extreme.  The most I could ask of you or any other skeptic would be to not indulge in contempt before investigation.

Duke, have you, James, or  the inventors taken any ground-plane measurements of these devices?

FR would show whatever bass extension differences exist between this cabinet and "conventional ones," and sweep at various levels would show as the claimed dynamic expansion at higher SPLs. The best way to quell skepticism is data, especially now that the invention has legal protection. I for one would love the device to do what's claimed. You seem to chase what actually matters in loudspeaker design, and in the past your public posts have led me to discover some great loudspeakers, such as the Gradient Revolution. But at this point it's hard to call the assertions as to performance of the MVW "claims," because (at least I haven't seen) any data to support them.

If I'm wrong about the absence of public data, I apologize and ask you to point me towards it. Because I've looked and haven't found it.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 23 Mar 2014, 02:07 pm
Not my place to answer for Duke, but I do feel compelled to respond to just one item asked for in the patent by Jim.  I don't know why it jumps out at me from all the other pertinent questions, but it does.  I do have more experience in running multiple transducers in this design. 

T/S parameters have very a small impact on the loudspeaker cabinet.   They're incredibly flexible as to driver choice.  I can take a dual 8" PA system top, drop 2 8" subwoofer transducers into it and it will perform admirably, better than a sealed or ported box.  That's true of all of the dual driver designs, and to a great degree of all the of single driver subwoofer versions.  The only T/S parameter we've defined as very important is F/S.  It needs to be minimum 80hz, 60-70 is optimum,  for a limited high range cabinet like a PA top.  As low as possible if a full range loudspeaker is desired.  For subwoofers the lower the better, depending on the application and sensitivity in the passband required.  QTS between .4 and .5 seem to be best also, but we've found many exceptions to that.     Those are the two starting points we use when selecting appropriate transducers. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 23 Mar 2014, 09:41 pm
Thanks for your thoughtful and professional post, Jim.  I apologize for this reply being slow; my internet connection has either been timing out or non-existent. 

My understanding is that the modern patent law protects the first to file, not the first to invent, assuming the patent is granted, so there is pressure to get something filed quickly.   If it were me, this would be among my concerns:  If the patent isn't granted and you've disclosed all of your trade secrets in the application, you've just given all of your intellectual property away for nothing in return.  The inventors have told me that their wording is deliberate, that they have followed the advice of their patent attorney, and that their intention is not to mislead customers, but rather to avoid assisting competitors who would rather be given the fruit of their labors for free instead of licensing it.   

They play things close to their vest.  It has only been since my last post here that I learned they do in fact have and use math models and a computer model.  Again, this is not something they are inclined to give away.

For now, I must say that after a first pass read of the patent, one is immediately disappointed in the lack of useful disclosure.

The patent system was originally set up with the basic premise that the government will offer a substantial monopoly on an invention for 17 years from the grant date (now, since 1995, 20 years from the filing date) in exchange for the inventor teaching the public enough reduction to practice information that one skilled in the art would be able to build a ‘best mode’ version of the invention.

In the patent there are no specifications, dimensions, references to T/S parameters and their relationship to the architecture, no relational dimensions of the different chamber sections, nothing whatsoever that would teach one how to create a reasonably functioning unit, let alone an optimized device.   

Also, there are no measurements disclosed and no comparative benchmarks illustrated.

This combined with the manner in which the system has been discussed by the practitioners and fans, does nothing to minimize one’s skepticism.

As I understand it, the intent of the inventors is to patent their basic alignment, rather than a specific loudspeaker design, and the figures are the starting points for the different embodiments of their alignment.   Using those figures as guides, a person could build a working model.  It would not be optimized, but it would be functional.   

Big E has their own forum (http://forum.bigeloudspeakers.com/), and if you register, they have a section entitled "Big E BS".   In their words:  "Want to call out the Big E inventors and/or manufacturers. Do it here. We welcome skeptics...just keep it clean and professional."

That said, I will keep an open mind and pursue further analysis.  Frankly, the main reason for doing so is based on my respect for your (Duke’s) understanding of which parameters impact loudspeaker sound quality and the assumption that he has studied the concept adequately to have uncovered some achievement that cannot be duplicated, or approached, with prior art technology.

At least, it is always entertaining to have a new item that generates excitement by tapping into that part of us that wants to believe there is something that can come along and transcend anything we have experienced before.

It could happen...

THANK YOU FOR HAVING AN OPEN MIND!!

I think everyone involved with this (myself included) have had to ask themselves whether they are self-deceived.   

A pivotal point early on for me was watching a youtube video (http://www.youtube.com/watch?v=AttKekXC2Do), listening through headphones.  In the video, a camera with attached high-quality microphone is moved around a gymnasium while a singer rehearses for a play, singing through the PA system.  I was surprised by the consistency as the camera/microphone is moved around; it was beyond what I would have expected from a good quality conventional PA system.  Listen to the song all the way through and pay attention to where the camera (with attached microphone) is in relation to the PA speakers, as the distance changes quite a bit, and remember this is in a high school gym, which is about as bad an environment for clarity and intelligibility as you can get.  This is the direct unprocessed feed from the microphone. 

I don't know whether that video clip will impresses anyone besides me, but after hearing it, I decided it was time to play my "if you can't beat 'em, join 'em" card, because I don't think I could beat the consistency-throughout-the-venue that that system demonstrated.  Granted the venues my home audio speakers are used in are a lot smaller, but still, to my ears that video demonstrates something done well that I wanted a piece of.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 23 Mar 2014, 09:58 pm
Here are some links to fluid dynamics modeling programs which could be used to analyze what is happening in the loudspeaker.
Open source freeware
http://www.openfoam.com/

http://www.macworld.com/article/1024399/tetruss.html
"TetrUSS is used in aerodynamics and fluid dynamics analysis, and has been used on major projects including High Speed Research / High Speed Civil Transport, Hyper-X, Abrupt Wing Stall, Mars Scout, Joint Strike Fighter and more. What's more, the software has been used in the civilian aerospace industry, academy, automotive, biomedical and civil engineering fields.

NASA research scientists and the Air Force Research Laboratory developed TetrUSS for their own use, and it has evolved into an unstructured-grid flow analysis and design Computation Fluid Dynamic (CFD) software system. It's available free of charge to U.S. entities, citizens and permanent residents. A free training course is even available at NASA Langley Research Center, as well."

Also fluid dynamics for your iPad
http://www.algorizk.com/
Navier Stokes equations
https://itunes.apple.com/nl/app/fluid-dynamics/id382274493?mt=8

Thank you very much, Scotty!  Steve Regier (one of the inventors) told me that he was unaware of these, and appreciates your taking the time to find and pass them along.   

Duke, have you, James, or  the inventors taken any ground-plane measurements of these devices?

FR would show whatever bass extension differences exist between this cabinet and "conventional ones," and sweep at various levels would show as the claimed dynamic expansion at higher SPLs. The best way to quell skepticism is data, especially now that the invention has legal protection. I for one would love the device to do what's claimed. You seem to chase what actually matters in loudspeaker design, and in the past your public posts have led me to discover some great loudspeakers, such as the Gradient Revolution. But at this point it's hard to call the assertions as to performance of the MVW "claims," because (at least I haven't seen) any data to support them.

If I'm wrong about the absence of public data, I apologize and ask you to point me towards it. Because I've looked and haven't found it.

I haven't done any ground-plane measurements or outdoor measurements, just on-a-stand measurements in my lab, some time-gated and others not, depending on what I'm looking for.  For then non-gated measurements, I compare them with measurements of known quantity speakers taken with the same speaker and microphone locations. 

This was posted on TalkBass some time ago: 
(http://www.talkbass.com/forum/attachment.php?attachmentid=329372&d=1365142239)

The red curve is one of my bass cabs, and the blue curve is a Big E bass cab.  I recognize the dips and peaks in my cab's curve well enough to conclude that the data is good.  This doesn't prove anything of course, but imo that Big E curve is darn good for a bass cab.   

My cab uses a single 15" woofer whose parameters predict -3 dB in the upper 50's in the size box I'm using.  My woofer is roughly a cross between the Eminence Kappalite 3015 and 3015LF woofers, and then the Big E cab uses eight of these little 5" woofers: 

http://www.faitalpro.com/products/files/5FE120/8/5FE120_datasheet_8.pdf

There will be more data in the future, addressing the points you bring up. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 23 Mar 2014, 10:43 pm
...The patent system was originally set up with the basic premise that the government will offer a substantial monopoly on an invention for 17 years from the grant date (now, since 1995, 20 years from the filing date) in exchange for the inventor teaching the public enough reduction to practice information that one skilled in the art would be able to build a ‘best mode’ version of the invention...

USPTO granted a friend of mine full patent for waveguide used for planar loudspeaker drivers.  I can't remember the exact costs associated with the process, but the total was in the neighborhood of $10k or $15k USD.  The first half of the cost goes toward the original application itself, the second half goes toward defending the request against persons who spend their life searching out and contesting every application request.  They contest and contest until they are convinced there is no further hope in contesting the patent, and the person requesting the patent intends to fight to the end.  In this case the "end" comprises the person requesting the patent spending about $5k to $7500 defending their original application.  Other independent professionals confirmed this scenario. 

Possessing full Patent after it is granted does not, by itself, protect IP.  If/when someone cheats and steals the protected IP for profit, the Patent holder must first find out, then decide whether to ignore it or sue the individual/industry committing the violation.  Patent attorneys cost about as much as any other attorney, maybe more.  At the end of the day, the IP holder is unlikely to recover the fees associated with the required legal action.  If the violators are overseas, forget it.   


Quote
I realize that a good demonstration has been achieved, and those that heard it were impressed, but anyone experienced in the industry knows that the number of external variables involved in show demonstrations is enormous.

That said, I will keep an open mind and pursue further analysis.  Frankly, the main reason for doing so is based on my respect for your (Duke’s) understanding of which parameters impact loudspeaker sound quality and the assumption that he has studied the concept adequately to have uncovered some achievement that cannot be duplicated, or approached, with prior art technology.

At least, it is always entertaining to have a new item that generates excitement by tapping into that part of us that wants to believe there is something that can come along and transcend anything we have experienced before.

It could happen…

All the best,

- Jim

I very much appreciate your professional input and attitude and look forward to your future comments on MVW cabinet loading.


Duke,
I humbly suggest you mention respective cabinet weights/volumes/dimensions: your TC15 reflex cabinet and MA85 (MVW 8x 5").  Also, just to confirm: all else being equal, at 1k Hz, actual MA85 output is about 2.5dB < TC15?     
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 28 Mar 2014, 09:15 pm
Jim! Classy post! Much appreciated  :thumb:

I'm not technically literate in loudspeaker design, but interested in these designs and hoping the dialogue remains productive among those of you with expertise.  :)

Thank you for the nice reception. 
Hopefully there will be the opportunity to come to a full understanding of the MVW concept and how it relates to the prior art, and if that is the case, I'm sure this will be one of the primary locations to be able to read all about it.
Cheers,
- Jim
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 28 Mar 2014, 09:44 pm
Not my place to answer for Duke, but I do feel compelled to respond to just one item asked for in the patent by Jim.  I don't know why it jumps out at me from all the other pertinent questions, but it does.  I do have more experience in running multiple transducers in this design. 

T/S parameters have very a small impact on the loudspeaker cabinet.   They're incredibly flexible as to driver choice.  I can take a dual 8" PA system top, drop 2 8" subwoofer transducers into it and it will perform admirably, better than a sealed or ported box.  That's true of all of the dual driver designs, and to a great degree of all the of single driver subwoofer versions.  The only T/S parameter we've defined as very important is F/S.  It needs to be minimum 80hz, 60-70 is optimum,  for a limited high range cabinet like a PA top.  As low as possible if a full range loudspeaker is desired.  For subwoofers the lower the better, depending on the application and sensitivity in the passband required.  QTS between .4 and .5 seem to be best also, but we've found many exceptions to that.     Those are the two starting points we use when selecting appropriate transducers.


Hello Leland,

I would not be so bold as to argue with someone that is actually building and testing these devices, when I have not yet had any direct experience with an MVW loudspeaker.  But, I would say that optimized T/S parameters almost always provides an opportunity to maximize performance over random, or wide ranging T/S parameters.  Historically, there has always been an optimal T/S combination and relationship that will optimize performance to a theoretical maximum capability relative to efficiency/bandwidth/enclosure volume for a given system architecture.

One aspect that can fool one into thinking that a system is relatively impervious to T/S parameter variations, is that one can often find that a system can utilize a wide range of Qt values, but this is usually only the case if one also alters Vas and Fs in a compensating manner.  If one follows this formulation in an optimal fashion, one can create a table that appears to have widely varying T/S parameters, but in actuality, it is a very specific T/S parameter 'balance' that is important for maximizing performance.

One excellent example of this is expressed in Keele's AES paper "A New Set of Sixth-Order Vented-Box Loudspeaker System Alignments" presented in 1974 AES 49th Convention and in the June 1975, Vol. 23 No. 5, wherein Qt values were altered from 0.150 to 0.598, while maintaining the same performance, by way of maintaining precisely corresponding variations in Fs and Vas.

This may be an effect you are observing with the MVW systems.

If it is the first system ever to be independent of T/S parameters, that will make for a very interesting study in itself.

All the best,

- Jim
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 28 Mar 2014, 10:10 pm
Thanks for your thoughtful and professional post, Jim.  I apologize for this reply being slow; my internet connection has either been timing out or non-existent. 

My understanding is that the modern patent law protects the first to file, not the first to invent, assuming the patent is granted, so there is pressure to get something filed quickly.   If it were me, this would be among my concerns:  If the patent isn't granted and you've disclosed all of your trade secrets in the application, you've just given all of your intellectual property away for nothing in return.  The inventors have told me that their wording is deliberate, that they have followed the advice of their patent attorney, and that their intention is not to mislead customers, but rather to avoid assisting competitors who would rather be given the fruit of their labors for free instead of licensing it.   

They play things close to their vest.  It has only been since my last post here that I learned they do in fact have and use math models and a computer model.  Again, this is not something they are inclined to give away.

As I understand it, the intent of the inventors is to patent their basic alignment, rather than a specific loudspeaker design, and the figures are the starting points for the different embodiments of their alignment.   Using those figures as guides, a person could build a working model.  It would not be optimized, but it would be functional.   

Hey Duke,

I won't put everyone to sleep with an extensive discussion of patent law and strategy, but there are just a couple points;

I must admit, my first concern was that my BS detector went off when reading the patent and finding it using similar language and presentation that I had seen on this site and the BigE site.  Usually, even if one wishes to use a marketing-smoke-screen to impress, and/or maintain secrecy, the patent application usually provides a more serious and thorough disclosure of a new invention, assuming there is actually something of value to disclose. 

In this case the patent was essentially a mirror of what has been mentioned to date in the forums.

So, if I were to assume that what is being disclosed is new and valid, I would shift my commentary on the patent to be that I believe the inventors may be putting themselves at risk of their patent being invalid, in that the requirements are such that one must teach their "best mode" version of an invention.  One can't teach substandard versions and attempt to keep the best versions as a trade secret and still expect to have a robust patent if challenged in court.

Relative to one of your comments, it would seem to me that they would have very little risk of not getting their patent granted if their invention is as novel as suggested by the inventors.

That said, they and their patent council have determined a strategy that they believe is the best approach, so I can only wish them well, with the result, hopefully, being that of an effective patent application and successful business.

Cheers,

- Jim
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 28 Mar 2014, 10:48 pm
USPTO granted a friend of mine full patent for waveguide used for planar loudspeaker drivers.  I can't remember the exact costs associated with the process, but the total was in the neighborhood of $10k or $15k USD.  The first half of the cost goes toward the original application itself, the second half goes toward defending the request against persons who spend their life searching out and contesting every application request.  They contest and contest until they are convinced there is no further hope in contesting the patent, and the person requesting the patent intends to fight to the end.  In this case the "end" comprises the person requesting the patent spending about $5k to $7500 defending their original application.  Other independent professionals confirmed this scenario. 

Possessing full Patent after it is granted still does nothing to protect one's invention.  If/when someone cheats and steals the protected IP for profit, the Patent holder must first find out, then decide whether to ignore it or sue the individual/industry committing the violation.  Patent attorneys cost about as much as any other attorney, maybe more.  At the end of the day, the IP holder is unlikely to recover the fees associated with the required legal action.  If the violators are overseas, forget it.   


I very much appreciate your professional input and attitude and look forward to your future comments on MVW cabinet loading.


Hi James,

I agree that the nature of our legal system is such that it is difficult for the small entity to justify the cost of patent prosecution and defense.  I often find that individuals and small audio companies file patents to be able to use the USPTO as a marketing validation of their invention, and they ultimately have no intention of every challenging any infringers, which can reach cost levels that are easily ten times that of the cost of the patent itself, even if they prevail in the court battle.

Unfortunately, patents tend to offer the best protection to those companies that are so large, and with such deep pockets, that most competitors would be too afraid to ever risk infringement.  The small guy seldom has the ability to scare-off infringers to any great degree.  It used to be that large companies were concerned about negative PR if seen beating up a small company, and the courts favored the small guy to a degree that the large corporations would think twice before challenging a small inventor, but that does not seem to be the case these days.

That said, I've also found that some large, deep pocket organizations are afraid of taking infringement risks, even against a little business, because there are many "ambulance chaser" attorneys that will take up the cause for a little guy to go after a big deep pocket settlement if they can keep 50% of the 'winnings'.

So, it's a gamble from either direction.  If an individual has a significant invention, I usually recommend getting a patent, and then licensing or partnering with a large organization, such that any company that might consider infringing your patent will see the 800 pound gorilla standing at your side, ready to support your defense. It tends to be a good approach to both earning a good income from the invention and provides an effective deterrent to infringers.

In terms of further analysis of the MVW, I will be glad to share my findings as I continue to explore the rather interesting design. 

I have explored the structure and have found the apparent changes in cross sectional area, vs. position along the length of the waveguide, consistent with other work that we have done to smooth the response in wide-band, multi-resonant quarter wave systems and transmission lines, without using any damping materials. 

Much of the effort is to smooth the pass band, while avoiding any sacrifice in efficiency, and effective minimization of diaphragm excursion, at the system low-end cut-off frequency.

I must mention that I am at a loss as to understanding how the system would act as a dynamic range expander, as has been suggested.  I also question whether that is something to strive for, as it implies a non-linearity in the system, which is not a desirable attribute if one is aiming to create a neutral device.

But, as with all the observers that are attempting to opine from the bleachers, I may very well have a significant gap in my knowledge about the actual structural and functional elements that are incorporated in an MVW system.

Best regards,

- Jim

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 28 Mar 2014, 11:54 pm
Jim,
I'd be indebted for your comment on the following.  Maybe 15 years ago Bob Carver (yes, that BC) told me that listening tests support the conclusion that human hearing sensitivity to THD in the bass range is so low that humans perceive little if any difference between 1% and 30% THD. 

I posted the above many times and shockingly, no one ever contradicted it.  (Conversely, I presume there is similar agreement that human sensitivity is extremely high to mid range phase and THD.  John Krutke of Zaph Audio posted that humans have little sensitivity to large FR aberrations in the top most octave, IIRC, windows as large as 6 dB.)

Back to bass THD: What's critical about Carver's point is that any money spent reducing THD below the threshold of audibility is wasted.  IOW, THD spec below the threshold of audibility is, in effect, nothing more than window dressing.  I don't know how true or false is Carver's statement, but my experience indicates a resounding yes.

A friend of mine used to build 400+# floor to ceiling line source subs with four or six active 12s.  Over the years I heard several similar sub systems, including IRS III in dedicated sound room.  Every time I heard them I was impressed.  I became convinced their most attractive quality was exceedingly low THD, you know, woofers barely moving except for canon shots, etc.  Now, with further experience of other sub systems with higher THD but natural mode damping features, I'm convinced the most audible feature of the line source subs was their natural mode damping for one of the most audible modes, being floor to ceiling bounce.       

I think the only spec I've ever seen re. modal effects is FR graph or simple numeric dB.  Considering that modal effects are 100% synthetic bass notes generated by distinct numeric relationships (listener or mic location, boundaries, speaker locations) I have always thought that modes expressed as THD can easily be well over 100%.  Please LOL at my guess and correct at will.

But the most critical defect about modes is their effect on timing.  I think of modal effect as a synthetic note only indirectly related to the original note in the music score, and this unrelated note continues playing over the next note appearing in the score. 

I suspect MVW has natural mode damping quality, and this may be among it's best, most audible, and most desirable features. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 29 Mar 2014, 02:02 am
Hello Jim Croft,

Thank you very much for your in-depth replies here.  I greatly appreciate your insights and observations, and your taking the time to offer your experienced advice about patents.   

I am preparing for an informal showing of several of my conventional-technology bass cabs in Seattle this weekend, so my internet time has been limited for the past several days, but next week I should be able to catch back up on things.

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 29 Mar 2014, 03:13 am
Jim,
I'd be indebted for your comment on the following.  Maybe 15 years ago Bob Carver (yes, that BC) told me that listening tests support the conclusion that human hearing sensitivity to THD in the bass range is so low that humans perceive little if any difference between 1% and 30% THD. 

I posted the above many times and shockingly, no one ever contradicted it.  (Conversely, I presume there is similar agreement that human sensitivity is extremely high to mid range phase and THD.  John Krutke of Zaph Audio posted that humans have little sensitivity to large FR aberrations in the top most octave, IIRC, windows as large as 6 dB.)

Back to bass THD: What's critical about Carver's point is that any money spent reducing THD below the threshold of audibility is wasted.  IOW, THD spec below the threshold of audibility is, in effect, nothing more than window dressing.  I don't know how true or false is Carver's statement, but my experience indicates a resounding yes.

A friend of mine used to build 400+# floor to ceiling line source subs with four or six active 12s.  Over the years I heard several similar sub systems, including IRS III in dedicated sound room.  Every time I heard them I was impressed.  I became convinced their most attractive quality was exceedingly low THD, you know, woofers barely moving except for canon shots, etc.  Now, with further experience of other sub systems with higher THD but natural mode damping features, I'm convinced the most audible feature of the line source subs was their natural mode damping for one of the most audible modes, being floor to ceiling bounce.       

I think the only spec I've ever seen re. modal effects is FR graph or simple numeric dB.  Considering that modal effects are 100% synthetic bass notes generated by distinct numeric relationships (listener or mic location, boundaries, speaker locations) I have always thought that modes expressed as THD can easily be well over 100%.  Please LOL at my guess and correct at will.

But the most critical defect about modes is their effect on timing.  I think of modal effect as a synthetic note only indirectly related to the original note in the music score, and this unrelated note continues playing over the next note appearing in the score. 

I suspect MVW has natural mode damping quality, and this may be among it's best, most audible, and most desirable features.

Hi James,

Just as a point of disclosure, or disclaimer, Bob hired me as a consultant in the early 1980’s to develop the Carver Amazing Loudspeaker (Planar Magnetic Line Source // Dipole Subwoofer) for him, and then in the early 1990’s, I was the Chief Technology Officer at Carver until 1997.  We did a lot of psycho-acoustic threshold testing over a two-decade period, leading up to, and during, that period.

I will attempt to give the short form answer to your question, and then we may want to take it off-line if you wish to explore it further, as this being Audio Kinesis’ forum, I don’t want to inappropriately high-jack Duke’s forum with a non-AK discussion.

In terms of the high threshold of up to approximately 30% for THD at low frequencies, all thresholds are context dependent, but, I’ll give a conditional answer of “Yes” relative to listening to music in a standard living room as the use-model where this very high threshold tends to be realized.

If you are to listen to sine waves, in an anechoic environment, the majority of listeners will have a much lower JND (Just Noticeable Detection) level threshold, by a factor of 10 or more.

So, what we have in standard living room, use-model conditions, is a situation wherein a number of parameters, such as THD and phase, for instance, are masked by more dominant issues, such as environment boundary reflections (modal and non-modal bands) and source program complexity.

“Linear” room modes at low frequencies will tend to dominate over many other “non-linear” forms of distortion (but not all). 

It is somewhat of an over-simplification, but to a great degree, one can make a Pareto list of variables in order of audible and masking dominance for a given audio system interface environment.  In general, as one minimizes or eliminates a top-level system global variable, the remaining local variables will move up on dominance and JND thresholds.

To restate, THD thresholds are determined to a great degree by our binaural, ear/brain psycho-acoustical hardware scanning an audio delivery system dominantly impacted by a the relationship to the environmental boundaries and the nature of the type of complexity of the particular program source (at a given moment).

Your friend's floor-to-ceiling line-source system delivering impressive sound quality is most likely, strongly influenced by, as you suggested, the vertical room mode (and if he maintained an infinite line source throughout the midrange also, it can make for even more improvement by minimizing vertical, correlated reflections, which can be dominant for voice colorations) and also for the multi voice coil derived minimization of thermal compression, which is a type of audible distortion that is more complex that simple THD.

I would suggest that Duke’s conservative approach to minimizing thermal compression is a significant benefit of his design approach.

The position that money spent reducing THD is wasted, is generally true, at least to the degree that one has not yet spent money reducing modal conditions to a point of equaling an anechoic space.

In terms of your notion that modal effects are 100% synthetic bass notes that could be expressed analogously to equal or greater than 100% THD, is I would say at least partially correct, at least as an analogy.

One has to be careful comparing linear vs. non-linear effects, as they disrupt the signal in very different ways from each other, and are also perceived differently from each other.  Modal effects are, mostly (that’s another story for another time), linear where as THD is by definition, non-linear.

That said, the modal output of a room is like adding an additional set of sound sources (like having more speakers that are not very good!, each with substantial frequency dependent amplitude errors) adding their outputs to the primary “real” LF speaker(s).  From this standpoint, one could say that the ‘positive’ modal output is greater than that of the primary signal, and therefore creates more than 100% “linear” distortion.

In terms of modal impact on timing, I’ll save that for later, as it is a more complex subject, both as a produced reality and a psychoacoustic perception.

In terms of MVW having natural mode damping qualities, I have to say that without your experience of the device, I am skeptical of its ability to effectively damp room modes.  From my initial evaluation of the internal structure, I DO believe, that MVW could be effective at damping the internal resonant modalities that normally are problematic with wave-resonant air-columns. In the past, I have effectively squelched negative modal effects of quarter wave air-columns by way of internal structures similar to that shown in the MVW patent.  But, again, I’m not sure what effect you are experiencing with MVW relative to what you experience as “natural mode damping”, so I’m open to learning more about that effect, if it does exist.

I hope this at least partially addresses some of what you were asking about.  If not, please redirect me to the more specific point you were looking to discuss.

Fun stuff…

All the best,

- Jim Croft
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 29 Mar 2014, 03:17 am
Hello Jim Croft,

Thank you very much for your in-depth replies here.  I greatly appreciate your insights and observations, and your taking the time to offer your experienced advice about patents.   

I am preparing for an informal showing of several of my conventional-technology bass cabs in Seattle this weekend, so my internet time has been limited for the past several days, but next week I should be able to catch back up on things.

Thanks, Duke.  Glad to come play in your neighborhood.

Good luck with the Seattle showing of your wares.

Cheers,

- Jim C.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 29 Mar 2014, 01:15 pm
Best MVW thread ever.  I cannot tell you how much I appreciate your interest and intellectual skepticism Jim.  We've gotten pretty used to being called liars and worse, instead of honest discussion.  Also the outside opinion from James, who brings much experience as a designer to the table.

The designers have been building a database as we try various transducers in the cabs.  But no apparent commonality other than FS and QTS really jump out.  That's not to say that there is not something we're not seeing.   

 I will completely confess I am out of my depth in this discussion, all of you have vastly more experience/knowledge than I.   I did know enough that when Steve and Tom first approached me about MVW cabs I pretty much ignored them for 6 months.  Loudspeakers don't do what they were telling me.  I finally made a road trip and heard them, first generation cabs.  Dove in headfirst.  The most convincing demonstration was in a high school gymnasium.  Dead even sound field, virtually no drop off front to back.  Nulls in two corners, about a foot wide and 3 ft long. 

I greatly look forward to providing you some systems to listen to.  I started putting the finishing touches on one of the cabinets yesterday.  Yea or nay, all opinions are welcome. 

Back to what I do best, running a table saw, instead of arguing with industry heavyweights.   :oops:
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 29 Mar 2014, 05:25 pm
Besides giving a huge thanks to Jim Croft for visiting and commenting, adding his wisdom to this forum, I'd like to say the Carver Amazing Loudspeaker is one of my all time favorite loudspeakers.  A friend of mine owns at least three pairs (industry pro, full time audio engineer) and another friend is a regular guy who owns a pair.  A truly great loudspeaker some times overlooked simply because of controversy related to Bob Carver.  I can't believe how great it is to have Mr. Croft in the house!   
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 29 Mar 2014, 06:45 pm
Besides giving a huge thanks to Jim Croft for visiting and commenting, adding his wisdom to this forum, I'd like to say the Carver Amazing Loudspeaker is one of my all time favorite loudspeakers.  A friend of mine owns at least three pairs (industry pro, full time audio engineer) and another friend is a regular guy who owns a pair.  A truly great loudspeaker some times overlooked simply because of controversy related to Bob Carver.  I can't believe how great it is to have Mr. Croft in the house!   

Thank you for the generous accolades, James.

Good to hear from a fan of the Carver Amazing Loudspeakers.  One of my favorite development projects.  It was a rare opportunity, in that we truly had a clean slate as a starting point.  The goal was to create new local variable elements to fall below known psychoacoustic thresholds, and to interface and couple with the Global environment as effectively as possible, regarding both modal effects and wide band room interaction, while achieving bandwidth extension (19Hz to 30kHz) and dynamic capability that had no precedent in prior art gradient devices. 

Almost every component had to be created from scratch.  There was nothing in the transducer and loudspeaker supplier catalogs that could meet our requirements.  So, we developed a new large area full range line source planar magnetic transducer from components and processes adapted from unusual, non-audio sources, such as weather-stripping component manufacturers and automobile pin-stripers. 

David Graebener (formerly of Speakerlab, Bohlender-Graebener, and now Executive VP of technology at Wisdom Audio) and I developed the planar magnetic line source transducer together.

The open-dipole woofer transducers had such unusual parameters we were rejected by over a dozen transducer manufacturers with the same reply; “It can’t be done”.  So we had to design them ourselves and have them built in Japan by the one manufacturer that was willing to be adventurous. 
(To optimize the novel gradient alignment, the four 12” woofers each had a 12 gram moving mass, an X-max of 20 mm, 26 Hz fs, and a Qts of 2.7; unusual to say the least).

Okay, enough self-serving reminiscence.  But, for those interested, I will be repeating the story daily, at the Old Folks Home for Loudspeaker Engineers, starting in about 15 years.

All the best,

- Jim C.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 30 Mar 2014, 08:44 pm
My professional studio experience ended circa Herbie Hancock's Headhunters and soon after Roy Buchanan's last album In The Beginning.  (Dr. Patrick Gleeson was likely at least equal to then-Walter-now Wendy Carlos in analog synthesizer proficiency...Gleeson tutored me in synthesizer programming, introduced Hancock to the synth, co-owned Different Fur Trading Co. studio at which Headhunters was recorded, and I'm pretty sure co-engineered the album with John Viera...I was apprentice engineer and programmed synth for In The Beginning at Sausalito Record Plant).

Suppose some particular studio or pro sound person "X" found every single performance quality of MVW simply irresistible...except for one quality being dynamic range increasing with SPL.  What is the least costly method whereby such person X could modify the signal inversely relative to the unwanted dynamic range expansion, and being otherwise completely transparent to performance quality?     

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 31 Mar 2014, 12:04 am
My professional studio experience ended circa Herbie Hancock's Headhunters and soon after Roy Buchanan's last album In The Beginning.  (Dr. Patrick Gleeson was likely at least equal to then-Walter-now Wendy Carlos in analog synthesizer proficiency...Gleeson tutored me in synthesizer programming, introduced Hancock to the synth, co-owned Different Fur Trading Co. studio at which Headhunters was recorded, and I'm pretty sure co-engineered the album with John Viera...I was apprentice engineer and programmed synth for In The Beginning at Sausalito Record Plant).

Suppose some particular studio or pro sound person "X" found every single performance quality of MVW simply irresistible...except for one quality being dynamic range increasing with SPL.  What is the least costly method whereby such person X could modify the signal inversely relative to the unwanted dynamic range expansion, and being otherwise completely transparent to performance quality?     

Hey James,

Great to learn more about your background.  Very interesting.

In terms of the dynamic range issue, assuming that it is real, then the first thing we would need to do is to capture the transfer function of the effect.  Then we can decide if there is a direct inverse process that is practical. 

Again, I don't yet know if it is a significant issue or not, but, if so, I think it would probably be best dealing with it acoustically.  It will be interesting to see how much the effect actually manifests itself, and then also determine how entrenched the effect is in the MVW "acoustic process".  Is it possible to isolate, and control, without altering other favorable attributes.

But, I think we are getting ahead of ourselves.

I am certainly curious to learn more about how a dynamic range expansion effect within a passive acoustic loading system can even come into existence in the first place.

Currently, if you were to list all of the individual positive attributes of the MVW, what would be on that list?

Also, is the system supposed to have inherent bandwidth/enclosure volume/efficiency advantages over the prior art, such that it surpasses Hoffman's Iron Law?

All the best,

- Jim C.

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: steve f on 31 Mar 2014, 12:24 am
From someone who finds some of this "over my pay grade" I am fascinated with the MVW concept. Also way cool to read the related anecdotal  stories. Thanks guys.

Steve
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: genjamon on 31 Mar 2014, 02:56 am
While the technical issues are also absolutely beyond my pay grade, I have to say this dynamic expansion business sounds suspiciously like a violation of either Newton's first or second laws, or both.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: James Romeyn on 31 Mar 2014, 04:58 am
While the technical issues are also absolutely beyond my pay grade, I have to say this dynamic expansion business sounds suspiciously like a violation of either Newton's first or second laws, or both.

Yes, it certainly does seem to turn certain laws of physics upside down.   
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 1 Apr 2014, 01:24 pm
I'll give some of these a go. 

Quote
I am certainly curious to learn more about how a dynamic range expansion effect within a passive acoustic loading system can even come into existence in the first place.

Electrically there's no change in sensitivity in the cabs.  Acoustically there appears to be.  At least to the ear.  What we do know for sure is the system creates a soundfield unlike anything else.  The closest comparison is a line array.  Most of our testing and real world applications have been in the pro sound field.  The MVW system creates a defined sound field that changes in size with the amount of power applied.  There's boundary that's very apparent when running a system outside, or in a large venue.  For example, running 4 2x8 prototype cabs per side at an outside show last year the engineer and I were walking the venue prior to the show with low power running.  About 30ft from the stage you would take a couple of steps and the sound would just drop, at least 6db.   During the show while the cabs were running up to power, that boundary effect had moved out approximately 300ft from the stage. My admittedly inaccurate phone was showing 3db dropoff per doubling of distance until I got to the boundary, when it converted to farfield dropoff.   A 4ft tall stack is certainly not enough to create line array effects via traditional cabs.  I will be providing the system for all the concerts in the park in my town this year, and this time I'm bringing real test gear. 

All I know for certain is the louder you play them, the better it gets.  One of the gremlins we've been chasing for a year is getting that at lower power levels.  The originals required about 30% to really create the soundfield.  We've got that down to about 10-15% for the full effect, and it's there even at low power, just not as apparent. 

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Currently, if you were to list all of the individual positive attributes of the MVW, what would be on that list?
It feels like wearing a fine pair of headphones.  Very in your head sound.  Imaging that rivals practically anything I've heard. Not just width, but depth also.  Imaging that has almost no sweet spot.  You can be on axis with a cab and still have imaging, not as wide, but it's still there.  Very little regard for placement.  It's just not critical.  They just work about anywhere.  That's not to say there's no optimums, but for the vast majority just set them up and play. 

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Also, is the system supposed to have inherent bandwidth/enclosure volume/efficiency advantages over the prior art, such that it surpasses Hoffman's Iron Law?

Nope, Hoffman still rules, but he gets bent pretty hard.  Because we get reinforcement through the side waveguides up to almost 5k, there's nearly as much output from them as there is off the face of the driver.  A typical MVW alignment with 2 drivers will have spl in the range of a normal ported cabinet with 4 drivers.  Complete integration occurs about 1-2 ft in front of the cabinet.

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: steve f on 8 Apr 2014, 02:41 am
Is there any chance that a pair might make the rounds of shows like Axpona or similar?
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 8 Apr 2014, 05:00 am
Just as a point of disclosure, or disclaimer, Bob hired me as a consultant in the early 1980’s to develop the Carver Amazing Loudspeaker (Planar Magnetic Line Source // Dipole Subwoofer) for him, and then in the early 1990’s, I was the Chief Technology Officer at Carver until 1997.  We did a lot of psycho-acoustic threshold testing over a two-decade period, leading up to, and during, that period.

YOU DESIGNED THE CARVER AMAZINGS?  Wow, that is one of the most intelligent loudspeaker designs of all time!  You are invited to talk all you want about the Carver Amazings or any other subject here, anytime!   I take off my virtual hat and bow deeply in your digital presence.   Bob Carver is indeed as smart as we thought, but for a different reason - he was smart enough to hire you! You are more than welcome to talk about anything you want here - in fact, you are actively invited to - I don't care if it's about designs that I compete against, your work is legendary and I don't want you to feel like you have to censor your speech.   

Also, is the system supposed to have inherent bandwidth/enclosure volume/efficiency advantages over the prior art, such that it surpasses Hoffman's Iron Law?

That's not a claim that I would make at this stage; I've seen woofers in MVW enclosures go a bit lower than I would have expected, but the box size ends up being large enough (in the MVW speakers I've had hands-on experience with) that, in my opinion, Hoffman doesn't seem to be overthrown.   

While the technical issues are also absolutely beyond my pay grade, I have to say this dynamic expansion business sounds suspiciously like a violation of either Newton's first or second laws, or both.

This is just speculation on my part:  Maybe as the SPL goes up, the acoustic radiation resistance of the MVW enclosure increases, resulting in improved impedance matching with the air, and the net result is a bump in efficiency compared with the low SPL condition.   

Is there any chance that a pair might make the rounds of shows like Axpona or similar?

We will be showing a MVW speaker at Rocky Mountain Audio Fest in early October, room 1100.  Current plan is to show a stand-mount design that is still under development at this point, but that hasn't been carved in stone yet.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: PMAT on 8 Apr 2014, 05:17 am
Duke, you hooked me and others with the openness of that invitation to speak of the Carver designs. Can't we all learn from other great deigns? Yes we can.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 8 Apr 2014, 05:29 am
Duke, you hooked me and others with the openness of that invitation to speak of the Carver designs. Can't we all learn from other great deigns? Yes we can.

Thank you!

JIRCO, if you want to start a new thread here with Carver Amazing in the title, or if you would rather I start the thread (as long as you'd be willing to post in it), let me know.   I think that would be of interest to a lot of people, and would do better with its own thread title.   If you don't have time and/or don't feel free to do so because of confidentiality agreements or considerations, like need to keep trade secrets secret, I certainly understand.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 8 Apr 2014, 06:32 pm
YOU DESIGNED THE CARVER AMAZINGS?  Wow, that is one of the most intelligent loudspeaker designs of all time!  You are invited to talk all you want about the Carver Amazings or any other subject here, anytime!   I take off my virtual hat and bow deeply in your digital presence.   Bob Carver is indeed as smart as we thought, but for a different reason - he was smart enough to hire you! You are more than welcome to talk about anything you want here - in fact, you are actively invited to - I don't care if it's about designs that I compete against, your work is legendary and I don't want you to feel like you have to censor your speech.   

Very kind words; Thanks, Duke.

Of the many loudspeakers I have developed over the years, the Amazings for Carver, and more recently, ( the clue ) for Sjofn HiFi, are two that were most enjoyable, primarily, because they were developed from a clean slate of no preconceived notions, other than attempting to raise the bar.  Both systems took about two years each to develop, which is a longer time frame than what is normally allowed.

I have a hard deadline to finish a new LF signal-processing patent I'm filing in the next couple days, but once that is complete I'm glad to answer questions or discuss any topic with you and your gang here any time or in any format that is works for all involved. 

I'll watch for any questions that pop up here, and just let me know if the conversation moves elsewhere.

Thanks again for your generous comments.

All the best,
 - Jim C.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210 (REVIEW)
Post by: JICRO on 18 Apr 2014, 03:05 pm
For those that are interested, the Spring 2014 issue of the online magazine Bass Gear has a review of an MVW product, with a background story,  a measurements section, and a little bit of technical disclosure by the inventors of the MVW systems.

Three different sections, from page 60 to page 73.

I was surprised that it hadn't been posted here, so I thought I would do so.

http://btpub.boyd-printing.com/publication/?i=204655&p=60 (http://btpub.boyd-printing.com/publication/?i=204655&p=60)

Enjoy,

- Jim C.

Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Rubbbq on 18 Apr 2014, 07:41 pm
These were Just delivered. To soon to know if it will be a love affair  :lol:, need to run them in for a bit. Didn't have proper stands, so I whip up some made of copper pipe I had sitting around....
(http://www.audiocircle.com/image.php?id=97945)
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Russell Dawkins on 18 Apr 2014, 07:52 pm
Very curious about your impressions. I like the copper pipe stands!
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Rubbbq on 18 Apr 2014, 08:01 pm
I literally got them an hour ago, to soon to tell. These are not from Duke, they are from speakerhardware.com . It is my understanding that Duke's are different in the crossover and possible the drivers but that I'm not sure about.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: PMAT on 21 Apr 2014, 04:00 am
Ok rub a dub dub, now you've had them for a while. Let's have it! :nono:
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 21 Apr 2014, 11:50 am
Duke's use different driver, different bigger cab, and a very different crossover.  Mine are Duke designed, but fairly straightforward.  Not nearly as complex.  A whole different price point is part of the  reason.  Designing for that last percentage of performance is expensive in time and materials, which is what you get with Duke's cabs.   

I like the stands, a lot.  It appears I got a pretty good match on the finish.  I thought that natural would be easy.  That's what I get for thinking. 

Those are GC25H's.   Front fired tweeter.  Not perfect response, but they demonstrate the MVW effect amply.  The front fired tweeter is a bit more directional in the hf than some of the higher priced cabs, which are on the way.  I personally love the sound of silk domes, and that's why it's in there.   
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Rubbbq on 22 Apr 2014, 09:12 pm
Unfortunately, I have nothing to report. My system is having some issues and I think I blew a fuse. I haven't had a chance to diagnose the situation :scratch:
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Leland Crooks on 28 Apr 2014, 12:48 pm
 :(
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 16 Aug 2014, 02:14 am
Congratulations to the BigE guys on having all their claims allowed and patent granted on the MVW technology.

Cheers,

- Jim C.
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 21 Aug 2014, 08:36 pm
Congratulations to the BigE guys on having all their claims allowed and patent granted on the MVW technology.

Cheers,

- Jim C.

Yeah, I'm pretty excited for Steve and Tom as well, and of course my business benefits from their success. 

I'm planning to show a new MVW design at RMAF in October.  Will you be exhibiting there? 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: JICRO on 21 Aug 2014, 09:02 pm
Yeah, I'm pretty excited for Steve and Tom as well, and of course my business benefits from their success. 

I'm planning to show a new MVW design at RMAF in October.  Will you be exhibiting there?

Hey Duke,

I was looking forward to when you might present your spin on the MVW architecture.

I'd be curious, if you are up for sharing, to hear what your updated thoughts are on the design, and its attributes.

I hope to make it RMAF this year. 
I may be helping in the SJOFN HiFi room demonstrating ( the clue ) and possibly a new complimentary Dynamic Range Module/Room Mode Sub. 

If I'm there, I'll definitely stop by to say "hello" and will look forward to hearing your latest wares.

All the best,

- Jim
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: Duke on 21 Aug 2014, 09:17 pm
Hey Duke,

I was looking forward to when you might present your spin on the MVW architecture.

I'd be curious, if you are up for sharing, to hear what your updated thoughts are on the design, and its attributes.

I hope to make it RMAF this year. 
I may be helping in the SJOFN HiFi room demonstrating ( the clue ) and possibly a new complimentary Dynamic Range Module/Room Mode Sub. 

If I'm there, I'll definitely stop by to say "hello" and will look forward to hearing your latest wares.

All the best,

- Jim

It will probably be a couple of weeks before I can pass along updated impressions, as Steve and Tom have refined the design in several areas since I last heard a pair.  My "show pair" will incorporate their latest and greatest, and it's being built now. 

I'm very much interested in hearing ( the clue ) and its Complimentary Dynamic Range Module/Room Mode Sub, and in meeting you as well. 
Title: Re: The Manipulated Vortex Waveguide speaker - the Event Horizon 210
Post by: arjank on 17 Mar 2015, 09:45 am
Hi Duke,

Just chiming in to see what you're up to outside your basscabs  :D

Grtz,
Arjan