[Duke]

That's the question Chris aka lonewolfny42 asked in a recent thread here, and in another it sounded like Boris aka audiovista was curious as well. 

So, let me talk about what's coming and what might be coming.

The Swarm is a done deal.  It's four-piece subwoofer system that's just waiting for one final little piece of the puzzle.  Briefly, the Swarm is intended to blend well with dipole speakers like Maggies and Quads.  By spreading four small subs around the room instead of using one or two big subs, the result is a low frequency soundfield that's a closer approximation of the sort of soundfield that dipoles reproduce.  So far those who have tried the system have been happy with it.  Price will be $1800 for the set.  Details to appear in a separate post in the not-too-distant future.

The following are in various stages of prototyping, modelling, or conceptualizing:

1.  For several months now I've been working on an affordble, tube-friendly, high efficiency speaker specifically intended to mate well with Audiovista's affordable tube amplifiers.  Thus far, I have not come up with something that I'm entirely happy with.  I want to do something significantly different from what Louis Chochos and Ed Schilling are doing, for example, but that doesn't leave much.  Target is under $2k, and the farther under the better.

2.  The Jazz Module concept could be scaled back in size and efficiency, to a roughly 90 dB floorstander with a smaller footprint.  Estimated price $3k.

3.  My bipolar Dream Makers have been pretty well received, with good feedback from audio shows along with a Golden Ear award.  So, I might try to do a less expensive, scaled-down version.  I'd trade off some bass extension and some efficiency, but maybe be able to cut the price in half.  Unfortunately, I wouldn't be able to keep the solid wood on all cabinet surfaces - I'd have to go to veneered MDF.  But there might be some real mileage in the format, as sort of a tube-friendly, equalization-free alternative to dynamic dipoles.   Probably $5k.

4.  I'm really encouraged by the performance of the Swarm system, so I might do a high-efficiency "satellite" speaker to go with it.  This could take two forms:

4a)  Monopole satellites, sort of like a high-efficiency, bass-deficient, smaller-box variation on the Jazz Modules, ballpark $3k, or

4b) Bipole satellites, sort of like a high-efficiency, bass-deficient, smaller-box variation on the Dream Makers, ballpark $5k.

5.  High-performance stand-mount.  The details are top secret for now, but if it works it would shoe-horn most of the performance of the Jazz Modules into a package measuring roughly 24" tall by 11" wide by 15" deep.   The price would probably be the same as the Jazz Modules - $4.5k a pair.   

6.  Multi-role loudspeaker, basically something similar in concept to the Jazz Modules with more rugged drivers in a utilitarian cabinet with prosound input jacks so that it can be used for a wide variety of applications.  Target is $3k, but I'd be lucky to keep it that low.

Now no way will my time and R&D budget allow me to do all of these projects.  I might get one or two done before the end of the year.  An obvious target date for one of them is the Rocky Mountain Audio Fest in October.  So...

If any of these projects look especially interesting to you (from either a hobbyist or a potential buyer standpoint), let me know. 

Also, if any of you want to make a suggestion about a possible product, please feel free to do so.  Ideally, start a new thread  (here in this circle) so that it stands out and attracts people who might have otherwise missed it. 

Thanks!

Duke

[zybar]

Duke,

Since I own Emerald Physics CS2's and Omega Revolutions, I am very interested in the Swarm package.

George

[NealH]

Interesting projects there.  I too like the thought behind the Swarm package.  And, for item #4 I like the idea of a mating bipole or OB satellite except, the price needs to be consistent with the Swarm package itself.  This would make it more value conscience.   Another thought would be to construct the bipole, or OB, in a slim 40'ish inch package which should also appeal to the home theater crowd.  Of course room concerns might be more problematic with an OB approach - I dont' know.   

[nullspace]

Hi Duke --

What I would love to see from AudioKinesis is a high-efficiency (maybe 100dB/1W) open baffle (100hz-1500hz)/waveguide(1k5hz and up). Filling <100hz left as an exercise for the end user. Broadly speaking, this would be one path to meeting the goals laid out by LO in his  elephantine 'Beyond the Ariel' thread over at diyAudio.

Just so happens to be the DIY project I've been working on for 6 months with little/no progress, so your market for such a speaker would >=1 for sure.

Regards,
John

PS: The Bottlehead guys have off and on offered an amp building class, where the participants get some lectures on theory and then a fair amount of hands-on experience building one of their kits. If you were ever to offer a speaker-building seminar, or just a class on loudspeaker measurement, I'd pony up some serious cash to attend. Just an idea...

[mateo]

One area somewhat addressed by the Jazz Modules, but I would love to see explored further, is a wall-friendly speaker.  North Acoustics does this, but there's certainly more room in the market IMHO.  A side benefit, which may or may not be a separate issue, is that a waveguide/single driver (examples of things you've worked with) might help with nearfield listening- put wall-friendly adjustable ports and nearfield ability in a small package and you have a small room winner.  Ha, that's so easy to type, wish it were that easy to do.

Other than that, I think the Dream Maker in a smaller physical footprint, sacrificing bass to be covered by the Swarm, could also be a real winner.  The Dream Maker is one of my dream speakers (hence the name), but I could never, ever imagine it being in a living space because of its size (the Jazz Modules, on the other hand...I might be giving you a call next year, Duke...).  I'm also fond of slimmer floorstanders instead of large monitors as a smallish-speaker format; it's a personal aesthetic bias, but I think not so drastic reduction/repackaing of your speakers should stay within floorstanders, at least at first.

/ramble

PS- I might be off on the Dream Maker size bit- I'm not really into the physics of everything, but I seem to recall the path from one driver to another around the side being a design factor...?

Matt

[cryoparts]

Go up.  I wonder what you could do for $15-20k?  Hmmmm?

Peace,

Lee

3.  My bipolar Dream Makers have been pretty well received, with good feedback from audio shows along with a Golden Ear award.  So, I might try to do a less expensive, scaled-down version.  I'd trade off some bass extension and some efficiency, but maybe be able to cut the price in half.  Unfortunately, I wouldn't be able to keep the solid wood on all cabinet surfaces - I'd have to go to veneered MDF.  But there might be some real mileage in the format, as sort of a tube-friendly, equalization-free alternative to dynamic dipoles.   Probably $5k.

[jhm731]

Duke-

Are the JM cabinets MDF?

[lonewolfny42]

Wow Duke.....looks like your going to be a very busy guy...
lots of good ideas.

Good luck.....

Some cowbell for you.......    

[Duke]

Thank you all for participating here!  This is great!

Okay, I'm going to reply to each one of you, but it's after midnight so I won't get very far in this post.

*   *   *   *   *

Zybar, I can't say that I'm sure the Swarm will be a worthwhile addition to the CS2.  But, some time in the not-too-distant future, I'm willing to risk the cost of round-trip shipping to find out.  If so, great; if not, c'est la vie.

Unfortunately I'm not familiar with the Omega Revolution, and couldn't find it on their website.  Can you tell me more about it?  Assuming it's a compact high-efficiency speaker, I think it's a reasonable candidate for the Swarm.

*   *   *   *   *

rnhood, great to hear from you! 

Okay, your idea is a very good one:  Namely, to do satellites in the same price ballpark as the Swarm.   I'd have to trade off some efficiency, but the impedance curve would still be smooth. 

Now the problem with doing an open baffle is this:  I really want the satellites to go down to 80 Hz, and to be capable of hitting 105 dB peaks without running into thermal or mechanical limitations.  The 80 Hz target is because if we cross over to the Swarm higher than 80 Hz, we won't have nearly as much freedom to spread the subs around the room, as we'll probably be able to hear their location. 

Now if I used a open small baffle along with a higher crossover, I'd be duplicating Bastani's work - which I don't want to do.  We can get down to 80 Hz either by using equalization, or by using a large baffle and maybe a specialized driver.  But... I don't want to duplicate Emerald Physics or Hawthorne Audio either.  While we're at it, the really cost-effective route would probably be Maggie MMG's plus the Swarm (even takign into account the Maggies' hidden amplifier cost).

So, if I'm going to do a poly-directional satellite, it would probably be a bipole.  I might be able to do fairly compact 91 dB tube-friendly bipole for roughly the same price ballpark as a Swarm set.  I'll do some modelling and report back. 

For the home theater crowd, I think that monopoles would work best because monopoles can be placed closer to the walls with good results; bipoles and dipoles need to be out from the wall several feet to avoid coloration from the reflected backwave energy arriving at the listening position too early.  A home theater friendly speaker system would be an interesting challenge.  I wish somebody made a shielded compression driver with the characteristics I want so that I could do a center channel.  But, maybe we'd get a decent phantom center channel using waveguides and 45 degrees of toe-in.  I'll have to try that some day and see if it works well.

*   *   *   *   *

Okay, that's all I have time for today.  I'll reply to some more tomorrow.

Rnhood's suggestion raises the issue of bipole vs dipole.  Obviously I've cast my lot with the bipole as a viable alternative to the dipole or open-baffle speaker, so at some point I should probably start a thread explaining in more detail why I made that choice.

In the meantime, thank you all!

Duke

[zybar]

Thank you all for participating here!  This is great!

Okay, I'm going to reply to each one of you, but it's after midnight so I won't get very far in this post.

*   *   *   *   *

Zybar, I can't say that I'm sure the Swarm will be a worthwhile addition to the CS2.  But, some time in the not-too-distant future, I'm willing to risk the cost of round-trip shipping to find out.  If so, great; if not, c'est la vie.

Unfortunately I'm not familiar with the Omega Revolution, and couldn't find it on their website.  Can you tell me more about it?  Assuming it's a compact high-efficiency speaker, I think it's a reasonable candidate for the Swarm.

*   *   *   *   *

Okay, that's all I have time for today.  I'll reply to some more tomorrow.

Rnhood's suggestion raises the issue of bipole vs dipole.  Obviously I've cast my lot with the bipole as a viable alternative to the dipole or open-baffle speaker, so at some point I should probably start a thread explaining in more detail why I made that choice.

In the meantime, thank you all!

Duke

Duke,

The Omega Revolutions are a box speaker that is now using a special single 8" Alinco Hemp driver built just for Omega Loudspeakers.  The speaker itself is 31"H x 15"W x 10.5"D. The base adds 10" to the height and is set up to be mass loaded (I have about 50 lbs of sand in each base).  Louis uses an aperiodic vent which helps in making the driver think it's in a larger cabinet amongst other things.  I will have to find out from Louis how low the Revolutions go, but I am guessing it is solid to around 40-45Hz when on the sand filled bases.

Here is a picture:




George

[Duke]

Nullspace is up next, with his interest in a 100 dB open baffle/waveguide speaker that goes down to 100 Hz.   

I will have to investigate this possibility.  My initial calculations indicate that either equalization or a very large baffle are needed, but maybe there are woofers out there that I'm unaware of.

I think could do a 98 dB bipolar speaker that would go down to 80 Hz and not take up much space... but, it wouldn't be cheap. 

As an aside, I've noticed that some of the systems claiming extremely high efficiency seem to be a bit optimistic - the Thiele/Small parameters for the woofers they use often come in several dB below what's claimed, and then when the speaker is actually measured... well, it falls a bit short.  Presumably they're assuming half-space loading, but I'm not sure that's always justified.

Yeah, it would be fun to do something that is competitive with what Lynn Olson is working on!  Must admit I've stopped following the thread as closely as I once did. 

I will look get some software and take a closer look at a high-efficiency dipole, as my dipole calculations at this point are just cookbook-based.   If I can do one that goes down to 80 Hz in a reasonably-sized wing-backed enclosure without undue equalization expense, then it becomes a possible front-runner. 

*   *   *   *   *

Mateo talks about a wall-friendly speaker.  Yesss!  I like the idea a lot!  I've long wanted to do a speaker whose characteristics would make it very small-room-friendly.  In my mind, I'm seeing controlled radiation patterns (to minimize early reflections) and placement up against walls or even in the corners.  Nope that's not ideal for imaging, but might be necessary because of limited space.  Some prototyping would be necessary to answer a few questions that I don't think a computer simulation can answer.

As for single-driver speakers, yes I have experimented with several single-driver speakers as well as coaxial or concentric drivers.  So far I don't feel like I've been able to meet all the goals I'd like to with either format.  Not to say that it can't be done (and several other designers are way ahead of me in this area), but for now at least I'm leaning towards having separate low and high frequency sections - woofer + waveguide, sorta like the Jazz Modules format.

On the Swarm-friendly variation of the Dream Maker, I'd want to retain a format where the box is considerably wider than it is deep.  This is part of how I address the wrap-around at low frequencies.

*   *   *   *   *

Lee of Cryoparts wonders what I could do for $15-20k.  Hmmm.  The Dream Maker's controlled-pattern offset bipole format is pretty much my best and brightest idea at this point, so I'd probably want to do some variation on that theme.  Assuming a handsome R&D budget, it would be fun to do a version with field-coil drivers and while we're dreaming maybe even beryllium diaphragms for the compression drivers.  Such a speaker might well bust his $20k ceiling, though.

*   *   *   *   *

Jhm731 asks whether the Jazz Modules are made of MDF.

Mostly.  The front panel is solid walnut backed by 3/4 inch baltic birch, but all the other surfaces are walnut veneered MDF.   Internally, there are several contrained layer damping panels (not "dampening" - that's what happens when something gets wet), and a couple of baltic birch plywood window braces.  There's also some internal reinforcement to beef up the cut-outs on the back panel.  On the bottom are a couple of solid walnut feet, so that when the speaker is moved around the MDF corners and edges don't get all chipped up.

*   *   *   *   *

Chris thinks I'm gonna be a busy guy. With any luck, busier than a two-dollar whorehouse on a Saturday night!

We lose money on every pair, but we make up for it in volume...

Seriously, not all of this is going to happen, at least not this year.  But I'm shooting for showcasinging one of these projects at the Rocky Mountain show in October. 

*   *   *   *   *

Zybar posted a beautiful picture of the Omega Revolution, worth at least 1.0k words, and a detailed description.  Thank you!  Okay, I think the Swarm is a reasonable candidate for a subwoofer system for the Revolution.  Not to take anything away from Louis's subwoofer systems, you understand!  Louis does fantastic work - he is innovative and a perfectionist who knows what he's doing. 

*   *   *   *   *

Okay, I'm leaning towards trying to combine a couple of these ideas into one speaker.  For example, mateo's wall-friendly speaker might, with a mere change in port tuning, become a monopole satellite for the Swarm.  That change in tuning would require a screwdriver, some electrical tape, and maybe ten minutes at the most.  If I do the speaker as a stand-mount and use veneered MDF, I could keep the cost comparable to the Swarm, resulting in a fairly flexible, room-friendly full-range package for about four grand - consistent with rnhood's suggestion.

That's just an off-the-top-of-my-head thought at this point.  I still want to do some modelling of dipoles. 

I invite any further comment anybody wants to make.  I'll probably be coming back to ya'll for more opinions and input as I narrow things down a bit.

Thank you all very much. 

Best wishes,

Duke

[nullspace]

Nullspace is up next, with his interest in a 100 dB open baffle/waveguide speaker that goes down to 100 Hz.   

I will have to investigate this possibility.  My initial calculations indicate that either equalization or a very large baffle are needed, but maybe there are woofers out there that I'm unaware of.

I think could do a 98 dB bipolar speaker that would go down to 80 Hz and not take up much space... but, it wouldn't be cheap. 

Thanks for your comments Duke. For me, the sub-1000hz has been the easy part. I'm using a pair of the ToneTubby AlNiCo 12", one as midbass and the other as a helper woofer, on a flat 18"Wx35"H baffle and ungated in-room measurements have the setup flat to ~120hz and rolling off quickly after that. Theile/Small sensitivity is ~97.5dB/1W, so on an open baffle that gets us to our 100db mark; freq. response measurement comparisons to Beyma CP380M and B&CDE250 bear this out. It's the whole doing reputable measurements and putting together a reasonable crossover that's causing me sleepless nights...

By the by, I'm already booked for RMAF and very much looking forward to whatever you come up with for the show.

Regards,
John

[Berndt]

I would like to see the future of AudioKinesis include a new/improved website?
Duke, I'd like to see more info on your websight. Maybe a video tour of the batcave?
Also like to see a links to friends websights?
How about your "B" stock?
How about owners pictures? (Not meaning to ride your coat tails... )

[Duke]

Nullspace, thanks.  Yeah those Alnico Tone Tubbys do look very interesting - Alnico & hemp, large diameter cone, high efficiency, high Qts for open baffle...  I'm under the impression that the linear x-max is very small.  Do you high-pass filter them, or is it not a problem in practice?  I have memories of low x-max wideband drivers losing coherence on loud complex passages, and I attributed it to the voice coil spending too much time outside of the linear zone.  If one Tone Tubby is a "helper woofer", I think that implies that the impedance curve has a "shelf ", and is 4 ohms at the bottom end and 8 ohm higher up (or 8 and 16 ohms - depending on whether you've got the 8 ohm or 16 ohm versions).  Correct me if I'm wrong.  My whole set of assumptions could well be wrong.

Crossovers can indeed induce sleepless nights.  I spent about 600 hours doing a crossover once... but it wasn't 600 hours straight; I did take a few breaks for sleep.  I'd say 580 of those hours were spent learning what didn't work in that application.  So, my next crossovers should only take me 40 hours or so. 

Looking foward to seeing you at RMAF.  I'll be in room 1100, probably sharing it with Atma-Sphere.  Please make sure and introduce your self using both of your names, so I'll be able to mentally connect Nullspace with whatever other name you go by.  And hey, if Nullspace is your real name, that's cool too!

*   *   *   *   *

Berndt, great to hear from you!

Yeah, the website could use some updating.  I'm not real good about that...

I'll probably post notices of B-stock here, as that's easier to do.  I'm not website-savvy yet (hoping to take a class later this summer though).   

And Owner's Pictures... YES!  That's a great idea.  I wonder if any owners would be interested, though??

The video tour of the batcave would reveal just how... ah... nevermind... my operation really is.

Cheers,

Duke

[nullspace]

Nullspace, thanks.  Yeah those Alnico Tone Tubbys do look very interesting - Alnico & hemp, large diameter cone, high efficiency, high Qts for open baffle...  I'm under the impression that the linear x-max is very small.  Do you high-pass filter them, or is it not a problem in practice?  I have memories of low x-max wideband drivers losing coherence on loud complex passages, and I attributed it to the voice coil spending too much time outside of the linear zone.  If one Tone Tubby is a "helper woofer", I think that implies that the impedance curve has a "shelf ", and is 4 ohms at the bottom end and 8 ohm higher up (or 8 and 16 ohms - depending on whether you've got the 8 ohm or 16 ohm versions).  Correct me if I'm wrong.  My whole set of assumptions could well be wrong.

Crossovers can indeed induce sleepless nights.  I spent about 600 hours doing a crossover once... but it wasn't 600 hours straight; I did take a few breaks for sleep.  I'd say 580 of those hours were spent learning what didn't work in that application.  So, my next crossovers should only take me 40 hours or so. 

Looking foward to seeing you at RMAF.  I'll be in room 1100, probably sharing it with Atma-Sphere.  Please make sure and introduce your self using both of your names, so I'll be able to mentally connect Nullspace with whatever other name you go by.  And hey, if Nullspace is your real name, that's cool too!

Cheers,

Duke

Hi Duke,

I don't hi-pass the ToneTubbys. I assume they only have a couple mm of linear xmax, but here the high Fs -- around 80hz -- works to our advantage. For me, that works just great. At my typical listening levels in a smallish room there's no chance of running out of linear travel. For a manufacturer, I would assume that this would be somthing to take a closer look at.

I've attached a plot of the impedence. I roll off the .5 woofer with a 4.7mH inductor. I have 4 ohm taps on my amplifier, so I haven't given much thought to the load presented to the amplifier by the woofers in the bass region. I have messed around with zobels and conjugates up around the crossover.



The moniker comes from my Econ grad school days at Duke. In mathematics, the nullspace of a matrix is a precise concept. It's also generally 'an open space'. The guys in my study group and I joked about opening a bar called "The Nullspace', which we thought was both a cool name for a college bar and precisely what a bar should not be -- empty. We thought the whole idea was uproariously funny.

Regards,
John

[Duke]

Hi John aka nullspace,

Great story behind your moniker!  I like the name of your school too.  Dignified, but in a mean streets/hired muscle/bad dog kinda way.

Thanks for the impedance measurement - is that just 1 driver, or 1.5?  It looks like just 1 from here.

Right now I'm doing more production than R&D (which is actually kinda nice), but soon as I get caught up I want to do some experimenting. 

Duke

[nullspace]

Hey Duke --

That's just one driver. I'll keep an eye out for any of your musings concerning forthcoming experiments.

Regards,
John

[Taterworks]

I'd personally like to see a two-way vented-reflex bookshelf-style standmount with the high-excursion variant of John Janowitz's new 6.5" midbass and a waveguide-loaded HF element of some sort that would allow a relatively low crossover point. Keep it under 2.5k/pair, and I may order a set. The mid driver itself looks like a true cost-no-object piece, with exotic cone fiber made from seed pods of some tropical tree, and lots of copper in the motor.

Also, I'd like to see more professional reviews. Send a set from your Planetarium series to 6moons.com or some similar site, and let's see what they have to say.

[Brucemck]

I vote with NullSpace and CryoParts: state of the art, extreme efficiency (SET friendly), close to cost no object, making new LO design sound like a tabletop Bose.

Would be ok, perhaps even desirable, if very lowest octaves were handled by separately powered bass unit

[jimdgoulding]

Duke-  A guy on a forum in the UK queried me about what would happen using my thing on his speakers.  Told him my thing couldn't ameliorate what wasn't there.  That the designer had taken diffraction into account already.  Dude told readers I was a good guy for not taking him for a ride.  Lives in North Carolina.  Don't know his name.  He's a customer of yours.  Listens with Jazz Modules.  Nice to see word about you is getting around.  I'll help when I can.  Best wishes for the New Year and Merry Christmas.  Ho-ho-ho.