[Duke]

Ever since last year's Rocky Mountain show, I've been working on finding a way to bring the concepts embodied in the Dream Maker LCS system to a more affordable price point with minimal compromise.   A few days ago final drawings were delivered to my woodworker, so we're in the home stretch.

The main performance goal is to bring the rich timbre and sense of envelopment of Jim Romeyn's invention into a more or less conventional-footprint system that can be placed quite close to the wall.   I think this will be a significant step forward in what a small-room-friendly speaker can do.   

This will be a ported system with multiple small pluggable ports to provide a lot of flexibility in adapting to the room acoustics (along with user-adjustable top end balance).   In sealed-box mode the low-end extension will be more like 80 Hz or so, making this system a good candidate for adding a Swarm as an upgrade.   

Preliminary specs include 8 ohms; 92 dB; typical low end extension to about 40 Hz ballpark; and negligible thermal compression up to about 108 dB.   What doesn't show up in the specs are the psychoacoustic benefits (both timbrally and spatially) of having the right amount of relatively late-arrival spectrally-correct reverberant energy.

Price will probably be 4.5 grand/system.  This is similar to the original Jazz Modules of yesteryear (which were 4.5 grand), but with significant improvements in several areas.   

And maybe best of all from the marketing department's standpoint, this won't be a monolithic floorstander, for a change.   Sorry, you'll have to wait until I can post photos. 

[JLM]

This is good news, just wish 'more affordable' was even 'more affordable' but those nasty laws of physics I'm sure interfere. 

Probably no way to "reasonably" reduce cost of say the Plantarium Alpha monitors (F3 = 70 Hz).  That approach makes so much sense to me, but the price (¢4,000/pair) gives my great pause.

[Duke]

This is good news, just wish 'more affordable' was even 'more affordable' but those nasty laws of physics I'm sure interfere. 

Probably no way to "reasonably" reduce cost of say the Plantarium Alpha monitors (F3 = 70 Hz).  That approach makes so much sense to me, but the price (¢4,000/pair) gives my great pause.

Can't say I blame you a bit for wishing for "even more affordable", and if it turns out that my costs are a bit less than anticipated, that will show up in the pricing. 

Each speaker enclosure houses two independent two-way speaker systems, each optimized for its particular job.  The enclosure itself is quite labor-intensive; the labor cost will probably be 2-3 times higher than is normal for my floorstanders.   And I really don't like to skimp on dynamic capability for my drivers because I think that's an important area that most home audio speakers fall short on.

On the dynamics thing:  I like for the peaks to be uncompressed.  My general rule of thumb for achieving this is, I want the drivers to be able hit those peaks at 1/10th their rated power handling.   And that would be based on their RMS (or more likely AES) power handling, not "music program" (which is twice as high), and not "peak" (which can be inflated enormously by using a shorter and shorter duration peak).   My focus is not so much on keeping the voice coils from melting; rather, it's on keeping them from getting hot in the first place. 

High efficiency and/or large diameter (or multiple) voice coils in each frequency range will get us there, but they may present other challenges along the way.
 
Anyway following these guidelines, if we want 90 dB average SPL and uncompressed peaks 20 dB higher, we need a system that can deliver 110 dB at 1/10th its RMS rated power handling.   Well in this system I fell short a little bit.   The AES power handling of the system is 400 watts, and the claimed efficiency is 92 dB, for a calculated 108 dB at 1/10th power (40 watts).   That's still pretty good.

And, there is a hidden cost savings from the higher-than-average efficiency:  Reduced amplifier power requirement.

To hit that same 108 dB peak, a "typical" 87 dB efficient speaker would need about 150 watts.  And this is before we factor in thermal compression - it that system's RMS power handling is 150 watts RMS (or 300 watts "music program"), well we might actually need something more like 250 watts to deliver a 108 dB peak. 

Depending on how expensive your taste in amplification is, being able to do well with 1/3 to 1/5 the amplifier power might make a significant difference.

A rule of thumb among the SET guys is, shoot for an amp/speaker combination that would theoretically give you 102 dB, and adjust from there for your room size and listening style.   This system would hit 102 dB with 10 watts, so that would probably be a decent ballpark starting point for tube amps (for solid state I'd like another 3 dB headroom before clipping sets in, so more like 20 watts). 

So back to the specifics here, and a look at how my "claimed" efficiency is derived.   Each box will have four 6" midwoofers in it, partially so that we can run 'em in series-parallel and end up with an 8-ohm load.   Each is 89 dB efficient based on its T/S parameters - which is a conservative yardstick (the manufacturer's spec sheet says 91 dB, and eyeballing the curve that's not based on a midrange peak).   Four 89 dB midwoofers would theoretically give us 95 dB efficiency, but again I take a conservative path because half of the midwoofers are dedicated to the reverberant field.   If I were making my efficiency claim based on an optimistic yardstick, I could easily claim into the upper 90's.  If I also added several dB in anticipation of the reverberant sound's contribution at the listening position, might even claim 100 dB.  This isn't so far-fetched:  An amplifier manufacturer once compared one of my 93 dB speakers with a "101 dB" speaker by someone else, and said that they sounded as if they were the same efficiency.  (Ever run into a situation where, on paper, the speaker/amp combination should play plenty loud, yet it's falling well short?  Optimistic yardsticks.  I'd rather lose those sales than have someone be disappointed with something they bought from me.)

My point being, there's decent value for my asking price.

Sorry for the long-winded tangent, dynamic capability is not the raison d'etre of this system; rather, getting the reverberant field right is.  But the dynamics will be there too, which isn't always the case. 

[JLM]

I agree that your logic regarding dynamics is spot on, if not overly ambitious for real worlders (with family/neighbors to consider, limited room sizes, and puny budgets).

Just curious, but how does the Plantarium Alpha main speakers compare to these?

[Duke]

I agree that your logic regarding dynamics is spot on, if not overly ambitious for real worlders (with family/neighbors to consider, limited room sizes, and puny budgets).

I have tried a number of times to come up with a considerably more affordable speaker, and of course I can do so, but so far haven't felt like any of my prototypes offered a significant advantage over the competition.   If I can use high quality prosound drivers, and/or build an intelligent polydirectional, then I think I have something to offer.   But as my flexibility gets limited by cost constraints, my designs start to look more and more like everyone else's, and I have no desire to do a "me too" product. 

That doesn't mean I've given up... just that I haven't gotten there yet. 

Just curious, but how does the Plantarium Alpha main speakers compare to these?

The Planetarium Alphas are more efficient but can't be used without a sub... well, not easily.  Actually a pair did get used without a sub at T.H.E. Show in Las Vegas a few years ago.   Someone on the source-component side liked the dynamics of the Planetarium Alphas but wanted to use them with an ubersub from another manufacturer, which was fine.  Well the amplifier for the ubersub went out first day of the show.   Fortunately the source component included powerful EQ capability, so the Planetarium Alphas were EQ'd to deliver good bass well down into the 30's. They had enough excursion capability to get there at high levels without farting out, something not many "satellite speakers" could do.  Of course my woofer has about four times the cone area and nearly twice the linear excursion of typical satellite speakers, so that helped!

I have switched to using rectangular waveguide-style horns augmented by a rear-firing tweet (to fill in the reverberant field), so a current-day version of the Planetarium Alpha would look different, and would outperform the original.   

Okay, back to the comparision:  A modern-day Planetarium Alpha would be more efficient and ultimately go louder, and have better dynamic capability.   This new speaker I'm working on, let's call it the "Z speaker" for now, would have enough low end to be used without subs, more natural timbre, and would rival or surpass the best polydirectionals out there as far as combination of good imaging and sense of immersion in the acoustic space of the recording.   Both would have good sweet spot width when set uo correctly, and both would have good tonal balance from pretty much anywhere in the room.

Even if subwoofers are planned, the Z speaker would still be my recommendation unless very high SPLs were called for.  That additional spectrally-correct reverberant energy it puts out makes more of a contribution to natural timbre that you would think, and imo that's what matters most.  The improved sense of envelopment is nice, and adds to the feel of being at a live performance, but imo timbre is job one.

In sealed box mode the Z speaker goes down to about 75 Hz, and then the Swarm (or whatever) would take over.  Or the Z could be used as a low-tuned vented box, and then the sub(s) would be augmenting the very bottom end, instead of supplying all of it.  The Z speaker will be quite flexible, among my lineup only surpassed in that regard by the Dream Maker LCS system.

[matt.w]

Man, this has me interested. Any updates?

[Duke]

Man, this has me interested. Any updates?

I should be able to pick up the first set of Z speaker cabinets from my woodworker in the next few days, and then I can get to work on the crossover (in this case in particular, I want to use the actual enclosures for designing the crossover, rather than a test box that's an approximation).

Earlier today I went to my woodworker's shop and took a picture of one of the Z's, in the middle of getting clear-coated: 



Imagine looking at it from the side, and you'll see where the "Z" comes from.

Approximate dimensions are 42" tall, 16" wide, 13" deep for the top section, and the base is 18" deep. 

The top section is the airspace for the front-firing array, and the slant section + base are the airspace for the upfiring LCS array.  There are horizontal window-pane braces in between the cut-outs, and I will be adding some bracing to the top panel.   

The Z speaker will get a real name once I've completed the crossover design.  The reason I don't name speakers in advance is, it's harder to come up with a good name than it is to come up with a new speaker design!

The Z speakers will make their debut at T.H.E. Show in Newport Beach, which starts one month from today.   They will be in the Electra Fidelity room, Room 920.  Tony Chippelo of Electra Fidelity is a longtime friend turned dealer.  Inventor Jim Romeyn will also be there, but I probably won't make it. 

[Charles Calkins]

Duke:

  Call your new speaker DEE speaker!!!
  Cabinets look GREAT!!! Hope I get a chance to listen to them someday.

                                                               Cheers
                                                                 Charlie

[James Romeyn]

Some details that might push you over the edge to make the trip to Newport.  The associated gear driving Z Speaker at THE Show is as good as it gets!  Bring CDs and 1/4" analog master tape if you have any!  Tony below mentions the system plays Memory Stick but not sure what digital formats are supported.     

Newport Beach THE Show, Hilton Hotel Room 920 (not Tony's second room 923), 30 May-1 June 2014  http://theshownewport.com/visitors/exhibitors.html  Show System...
Music Sources: Otari MX5050 MkIII reel to reel, 15ips, stereo 1/4", heads feed custom tube tape head preamp built into Atma-Sphere preamp...Master Tapes: Paul Stubblebine Tape Project and Opus Three/Sweden...Digital Source: Resolution Audio Cantata CDP and Streamer....Power Amps: Electra-Fidelity 300B mono 10-12W....also Atma-Sphere M60 OTL, 60W @ 8 Ohm or 100W @ 32 Ohm depending on Z Speaker configuration

Sensitivity 93 dB

Input impedance, one channel comprises one Main Speaker (MS) top/forward firing section + one Effects Speaker (ES) base/up firing section:
MS 16 Ohm
ES 16 Ohm

Power MS and ES each with separate amp (four amp channels per stereo pair) or parallel-wire MS + ES for 8 Ohms with one amp channel. 

Bass via four 6.5" drivers per channel successfully employed in prototype bass guitar cabinet.  Unique natural bass mode cancelling effect available in no other loudspeaker except larger Dream Maker LCS.

Treble drivers: Main Speaker horn loaded compression driver, adjustable gain.  Effects Speaker: four 1" soft domes, adjustable gain.

Two ports per MS/ES, four ports per channel, eight ports total per stereo pair...each port can operate either open or sealed for wide latitude in variable bass tuning for premium response in any room.  Eight tunable ports + aforementioned LCS natural bass mode damping feature yield linear and natural bass throughout the listening room, and minimize hot spots as results from digital EQ.

We will bring a switch to turn the Effects Speaker on/off.  Judge for yourself the value of LCS or lack thereof. 

[Duke]

Thank you, Jim!

impedance, one channel comprises one Main Speaker top/forward firing (MS) + one Effects Speaker (ES) base/up firing:
MS 6 Ohm
ES 16 Ohm

Minor typo:  The main speaker section's impedance is 16 ohms, not 6 ohms.

At this point I can't guarantee that series connection (resulting in a 32 ohm load) will become a practical reality.  It's a lot harder tailoring the impedance curves of two significantly different speaker systems so that they work well when wired in series.   But if that does materialize, it will offer an attractive option for use with amps like the Atma-Sphere S-30 and M-60, both of which like to see a high impedance load.

Jim mentioned that these woofers were tested in a prototype bass cab.  Before that I tested them in another experimental system, and compared them with other high quality 6.5" woofers.   They're actually smoother than is normally ideal for bass guitar, and really only have one minor frequency response glitch across the spectrum (and it's an easy one to address).   

The theoretical calculated max SPL of the system (400 watts into 93 dB efficiency) will be 119 dB, which doesn't take into account thermal compression or mechanical limits, but then virtually nobody else admits to such things either.   That 400 watts is the RMS rating, not "music program" (which is twice as high), and not "peak" (which is whatever the marketing department wants).    Anyway at 10% of its rated RMS power handling thermal compression will be less than 1 dB, which corresponds to 40 watts, and 109 dB SPL.   So in addition to the benefits of the LCS configuration, this system will offer really good dynamics and will deliver with modest amplification.

[Russell Dawkins]

"ZZ" would actually be a pretty good name for this model, wouldn't it? The shape begs a name that refers to it, and you'd have a ready consumer group in ZZ Top fans.

[James Romeyn]

I wanted to add that LCS energizes the room different from other radiation patterns.  Image and stage density is increased such that sensitivity might compare more favorably than a regular mono pole speaker of the same rating.  Because the sound room's boundaries more thoroughly disappear (as per Scott Hull's comments 2014 RMAF), sound scape size increases.  The result is increased listening pleasure and more thorough suspension of the brain's natural tendency to disbelieve the illusion.  Spatial effects fill the room more like a good MBL setup, but the goal is more accurate image sizing.  Images detach from the boxes more like a good panel speaker too.  Then there's the natural bass mode damping feature.   

If all the drivers employed were forward firing like a regular mono pole, the sensitivity spec would increase but at the expense of the above described goodies.

I requested Duke also work on a future option of grinding the freshest raw nut butter this side of a gourmet kitchen, and automatic lawn mowing function while you sleep.  He resists to date, but I suggest it as often as possible and hope to wear him down to submission.         

[Clio09]

Thanks Duke and Jim for your kind words. I am more than honored to be able to use Duke's speakers in our room this year. As Jim mentioned Electra-Fidelity will have two rooms and the "Z" speakers will be in room 920 in the Hilton. We will have a pretty eclectic system as Jim mentioned. Our 300B SE amps, or more commonly known as the A3-500, based on a Class A3 circuit and a few proprietary tweaks resulting in extremely low IMD will be on display. These amps were used recently at Axpona and previously CES this year in Jeffrey Catalano's (High Water Sound) rooms with Horning and Cessaro speakers respectively.

Also, we will have Atma-Sphere components with the M-60 amps and a modified MP-3 preamp. The preamp is a full function linestage but in addition to the phono section Ralph added a tape head circuit. As Jim mentioned we will have an Otari Mx-5050 MKIII that was pulled from its console and modified to have the tape signal taken directly from the playback heads in balanced configuration and fed to the MP-3. One correction I would like to make to Jim's post is that playback is 15ips not 30ips. We will have a nice selection of master, production master, and Tape Project tapes on hand.

The digital front end is as Jim described and we will be using wired Ethernet networked for streaming music. We should be able to accommodate a USB stick and the Cantata can also play CDs. Lastly, I hope to be able to have the latest turntable design from Thom Mackris at Galibier Design on hand. So all told with Duke's new speakers this is shaping up to be one of the best set ups we have put together at a show. If you are attending the show please drop by for a listen.

[borism]

The speaker looks very cool! I would love to hear it. To throw another name suggestion in the hat, how about naming it ZED (the pronunciation of Z in Commonwealth English)?

[matt.w]

Thanks for the update!

The only thing that would ever draw me from my custom Planetarium Alphas is something multidirectional like this. Very small chance I'd ever actually switch, but all the recent developments are so intriguing.

Any reason for the move to smaller mids in an MTM arrangement? Would these guys also be angled 45 degrees to crossfire, or are they set more traditionally facing forward?

[Duke]

As Jim mentioned Electra-Fidelity will have two rooms and the "Z" speakers will be in room 920 in the Hilton. We will have a pretty eclectic system as Jim mentioned. Our 300B SE amps, or more commonly known as the A3-500, based on a Class A3 circuit and a few proprietary tweaks resulting in extremely low IMD will be on display...

Also, we will have Atma-Sphere components with the M-60 amps and a modified MP-3 preamp. The preamp is a full function linestage but in addition to the phono section Ralph added a tape head circuit. As Jim mentioned we will have an Otari Mx-5050 MKIII that was pulled from its console and modified to have the tape signal taken directly from the playback heads in balanced configuration and fed to the MP-3. One correction I would like to make to Jim's post is that playback is 15ips not 30ips. We will have a nice selection of master, production master, and Tape Project tapes on hand.

The digital front end is as Jim described and we will be using wired Ethernet networked for streaming music. We should be able to accommodate a USB stick and the Cantata can also play CDs. Lastly, I hope to be able to have the latest turntable design from Thom Mackris at Galibier Design on hand. So all told with Duke's new speakers this is shaping up to be one of the best set ups we have put together at a show. If you are attending the show please drop by for a listen.

Wow, that's pretty fantastic!  My turn to be honored that my speakers will be in one of your rooms! 

"ZZ" would actually be a pretty good name for this model, wouldn't it? The shape begs a name that refers to it, and you'd have a ready consumer group in ZZ Top fans.

The speaker looks very cool! I would love to hear it. To throw another name suggestion in the hat, how about naming it ZED (the pronunciation of Z in Commonwealth English)?

Thanks guys, just to be clear, at this point there's a name lined up.  I just like to hold back until I've actually heard the speaker.

Thanks for the update!

The only thing that would ever draw me from my custom Planetarium Alphas is something multidirectional like this. Very small chance I'd ever actually switch, but all the recent developments are so intriguing.

The original Dream Maker LCS effects speakers, or perhaps a scaled-back version, could be added to your Planetarium Alphas, so you could sort of have your cake and eat it too. 

Any reason for the move to smaller mids in an MTM arrangement? Would these guys also be angled 45 degrees to crossfire, or are they set more traditionally facing forward?

The smaller woofer/MTM arrangement allows me to bring the parts cost and internal volume down.  I wanted 16-ohm sections so that they'd still be a reasonable 8-ohm load when wired in parallel.   It took me a while to find a small woofer that didn't sound dynamically squashed to me, having been spoiled by big prosound woofers with very powerful magnets. 

And yes, the design should work well with the 45-degree toe-in, but be a little bit more forgiving of more "conventional" setup. 

[jtwrace]

Look forward to hearing them at RMAF 2014.   

[James Romeyn]

Thanks for the update!

The only thing that would ever draw me from my custom Planetarium Alphas is something multidirectional like this. Very small chance I'd ever actually switch, but all the recent developments are so intriguing.

Any reason for the move to smaller mids in an MTM arrangement? Would these guys also be angled 45 degrees to crossfire, or are they set more traditionally facing forward?

My 2c till Duke chimes in.

Dream Maker LCS was the first commercial product with LCS radiation pattern. 

In a nutshell, an ideal LCS speaker system comprises so-called Main Speaker with dry, focused, smaller radiation pattern for low magnitude of reflections off boundaries and furnishings.  Conversely, the LCS so-called "Effects Speaker" supplies late-arriving high-magnitude reflections.  Beyond that, I can not confirm nor deny anything else is critical to performance. 

"Power response" is the sum total mix of a speaker's direct and reflected energy, a controversial subject in loudspeaker design.  One can argue that power response defines subjective opinion more than on-axis response. 

Compared to LCS other radiation patterns have less options in their power response.  For mono poles, reflections from boundaries and furnishings in proximity to the drivers generally arrive so early in relationship to on-axis that the ear detects those reflections as noise and/or distortion.  But too little reflection sounds overly dry.

The net effect of LCS "dry" on-axis energy + high-magnitude late-arriving reflected energy is even more than I previously mentioned.  When you visit the room and we turn the Effects on/off, those with good pitch sensitivity should notice the ES increases both detail and pitch center.  Yet if anything, it sounds even more relaxed.  Duke told me that Dr. Floyd Toole describes this ideal high magnitude late arriving reflected energy as a "second look" the ear uses to confirm it's first on-axis look.  This "second look" may increase pitch center.  The brain is quite sure that note was a C#, but ideal proper reflected energy seals the deal.  This increased pitch center may largely contribute to LCS' allowing the brain to relax and suspend disbelief that music exists in the room.     

This is another advantage vs. regular mono pole, in that mono poles generally increase negative etched effect as detail increases...the whole yin-yang thing.  LCS kind of cheats, letting us have our cake and eat it too. 

DM LCS employs rectangular wave guide which I believe shortens vertical radiation.  I believe the Z Speaker's symmetrical vertical array (with the symmetrical wave guide) minimizes the radiation pattern.   

I can't predict cross-fire angle with Z Speaker.  My favorite so far with DM LCS is extreme toe-in angle, almost 5' IFO centered listener, with Effects Speaker sitting square relative to the room's walls.  I tend to think Z Speaker will sound best with more moderate toe-in angle. 

[James Romeyn]

Duke said he might have working pair during the weekend.  Can't wait to hear them and see it in person.  ASAP I plan to bring one Z Speaker to my luthier's shop (Thorell Guitars) and attempt to fit Z Speaker in the photo tent.  If Z Speaker fits in the tent I'll shoot images till I get hungry, run out of flash card, or Ryan kicks me out, whichever comes first.

We bring state of the art DAC to RMAF, plus acoustic treatment, plus we developed the natural bass mode damping feature still unexplored at 2013 RM.  Even though Z Speaker is smaller than Dream Maker LCS, I believe the net effect at the show is much better overall performance except for the bottom half octave.

If so, that's a hat trick considering Z Speaker costs 50% less!         

[James Romeyn]

At 2014 Axpona Bill Dudleston of Legacy Audio gave video presentation on “The Future of Loudspeakers” (emphasis added).  http://parttimeaudiophile.com/2014/05/10/axpona-2014-legacy-audio/ :

"...Conventional speaker designs don’t radiate uniformly throughout their frequency range. They tend to be hyper-cardiod in the treble, broadly cardioid in the mids, while omni-directional in the bass. The result is a non-uniform and unnatural power response.

Full range Omnis can be more uniform, but can’t preserve stereo information due to high diffusion...More than 70%  of what you are hearing is room contribution and reflection and a ‘they are here’ character is imparted as the brain attaches the dominating room dependent signature. The bottom line is the acoustic shadow of the nose into the far ear is lost due to diffuse side fill.

Legacy has developed a radiation pattern control that is far more uniform with frequency and is not subject to early diffuse reflections. Additionally Legacy is nearing completion on a processor that will identify problematic room resonances from late energy buildup and move this energy back in time..."