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Anyone Else Using an Audio Kinesis Swarm or Debra Distributed Bass Array System?

I have Magnepan 2.7QR speakers and posted a similar question about 2 years ago on whether others were using an Audio Kinesis Swarm or Debra or any similar multiple sub distributed bass array system. I thought it might be useful for members to learn about this type of solution for attaining excellent bass performance in virtually any room and with any main speakers for both 2-ch stereo music and ht. I thought a new thread detailing this effective solution may be helpful and attract responses from other users of a distributed array sub system. I’m also wondering if there are any more members using one of these bass systems since I posted my original thread 2 yrs ago.


About 3 years ago I purchased the Audio Kinesis DEBRA (Distributed-Eq BassReflex Array) sub system from James Romeyn Music and Audio in Utah. Here’s a link describing the system:

http://jamesromeyn.com/old-pages/home-audio-gear/dsa-1-0-distributed-subwoofer-array-5-pieces-4k-usd...

This system is a bargain at $2,500 and well worth the investment. I rationalized the price by noting it’s about the same as a pair of very good regular subs.


The performance of this system in my 23’ x 14’ living room is excellent. The bass can be fast, tight and tuneful for music or loud and impactful for music and home theater. The subs seem to disappear since there are no audible clues to their locations; the bass is very well integrated into the music and movies.

From my personal experience, I was not convinced at the time of the reality of perceiving stereo bass but was willing to give it a try. I was originally thinking of buying 2 high quality subs such as Rhythmik, SVS, JL, Martin/Logan, Vandersteen or REL. I was skeptical of the DEBRA system at first but, after reading a lot of research about multiple sub systems on the internet, I decided to give it a try and I’m now very thankful that I did.

Because it is such an ideal system for me, and because I think it would work well in almost any room or system, I want to go into more detail about the system, its setup and the theory behind it. I have no affiliation with the company but will admit, after considerable phone and email time with the dealer, that I now consider James Romeyn a friend of mine but don’t know if he feels likewise.

The system consists of the following:

A dedicated Dayton Audio mono class A/B amp rated at 950 watts @ 4 ohms with dual A&B spkr output terminals.

Four 44lb. bass-reflex subs that measure a relatively small 23.75" H x 14.5" W x 10.375" D.

Each sub is ported on the bottom, supported by 3 spiked cones and contains a single 10" 4 ohm driver. The subs are designed to be facing, and within 2" of, the room walls.

The setup procedure is:

Sub#1 is hooked up and placed on its back (driver facing the ceiling) at the normal listening position. Music is played that has good and repetitive bass.

Walk around the edges of the room and determine exactly where the bass sounds best to you.

Attach the 3 spiked footers (flat adapters are also supplied for use on non-carpeted floors) to Sub#1 and position it upright facing the nearest wall to the spot you determined the bass sounded best.

Sub#2 is hooked up and placed on its back at the primary listening position. With sub 1 & 2 playing, continue walking around the edges of your room and determine again where the bass sounds best to you.

Attach the 3 spiked footers to Sub#2 and position it upright facing the nearest wall to the spot you determined the bass sounded best.

Repeat this procedure for sub 3 & 4.

Small positioning adjustments may need to be made for each sub due to avoiding furniture and the WAF.

Once completed, final sub hook up is done in series/parallel:

Attach a single wire from the amp’s speaker A’s pos. output terminal and to Sub#1’s pos. input terminal.

Attach a single wire from the amp’s speaker A’s neg. output terminal and to Sub#2’s neg. input terminal.

Attach a single wire from Sub#1’s neg. input terminal to Sub#2’s pos. input terminal.

Attach Sub 3 & 4 using this parallel method on the amp’s speaker B’s output terminals.

I ordered single, high quality and low gauge speaker wire along with the sub system for a very reasonable price. Once the ideal locations for the subs was determined, I drilled holes in my room’s floor to the crawl space below, and was able to hide the connecting wires.

I’m definitely not an expert on subs or room acoustics but, from my reading, here is how I understand the theory behind the distributed array sub systems:

The lower the frequency the longer the sound wave produced, or launched, into a room.

Since these waves can be even longer than the actual dimensions in many rooms, these low frequency waves bounce off room surfaces and the music may dictate subsequent bass waves being launched into this acoustic environment. These initial waves, their reflections and subsequent bass waves inevitably collide and cause ’standing waves’.

Areas in the room where sound waves meet can make the bass sound under emphasized, over emphasized or even totally missing (nulls caused by wave cancelation).

When one sub is launching low frequency waves from 1 specific location, areas in a specific room where bass response is not accurate will be numerous and predictable based on sub location and room dimensions.

Adding a 2nd sub to the room will decrease standing waves and increase bass accuracy and bass dispersion.

According to scientific studies I read (mainly Dr.Earl Geddes and Dr.Floyd O’Toole White Papers), standing waves are reduced, and bass accuracy and dispersion increased, as more subs are used in a given room. Their experiments utilized more subs than anyone would even consider for home use. They basically concluded that the more subs in a room, the fewer standing waves are produced/perceived and the better the bass quality and bass dispersion results.

However, they determined that most of the benefits are gained with the use of 4 subs, with only minimal and incremental gains in performance attained through additional subs. Due to practical room considerations, the researchers recommended 4 subs for an effective distributed bass array system. Here’s a link to an Absolute Sound review of the Audio Kinesis Swarm system which is almost identical to the Debra system I own:

http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

So that’s the equipment, set-up and the theory behind the DEBRA system and I can personally attest to its effectiveness in my room. I have 6 listening/viewing positions in my combination music and ht system in my living room. Bass response is equally good at all 6 positions without the use of acoustic devices (no absorbing or diffusing panels or bass traps) and without any electronic equalization (room analysis/correction equipment, software or eq). I should mention I’ve never had my system/room analyzed using a mike and software. From my purely subjective perspective, however, I’m confident the results would be good since I spent hours on the setup and critical listening from all six listening positions in my room. I would suggest this type of sub system as a viable alternative for anyone considering investing in one or more quality subs. The system is rated clean at 113 decibels at 20 hz. I’ve often heard and felt it go much lower. It feels and sounds clean and right but I can’t verify the decibels or lack of distortion.

Sorry this turned out so long and windy,

Tim

Also, my system photos are updated showing my current system with the subs and new electronics.



noble100
noble100's avatar
noble100 OP
2,419 posts
 
Hello Duke,

     First, I am thrilled, as I'm sure you are, to discover that you're still alive and kicking!
     I am thoroughly embarrassed and want to apologize profusely for my bone head mistake.  I wanted to find out a bit more about you and mistakenly googled 'Dick Lejeune' instead of 'Duke Lejeune'.  Dick Lejeune passed away on 2/18/2017 and I didn't notice I had renamed you on my Google search until I read your post today.  Honestly, I realize my explanation just further demonstrates my stupidity but I couldn't care less because.... YOU'RE ALIVE AND STILL WITH US!!!
      
     Secondly, thank you very much for your very interesting post on the AK Swarm and Debra beginnings and the finer points on how and why distributed bass arrays work so well.
     I was originally very skeptical about whether the Debra dba would work in my room (23' x 16' with 8' ceiling and a 6'h x 8'w window along one of the 23' walls) and my system (combo computer audio music and 5.1 surround ht system consisting of a laptop running JRiver software, 2 TB NAS, Oppo 105, class D amps, 'fast' Magnepan 2.7QR  large mains panels and CC3 center along with traditional cone in-ceiling Infinity rear surrounds).
     
     My initial bass improvement plan was to get 2 high quality conventional self- amplified subs.  I was talking to James Monteyn about having a pair of Hypex NCor class D mono amps built when he first informed me about the AK Debra dba system as an alternative that would provide sota in-room bass response in virtually any room.
     I recall thinking at the time that the Debra/Swarm dbas, at about the same price as a pair of good quality subs, sounded too good to be true.  I was also a bit concerned about accommodating the 4 subs in my combo A/V and living room.
     But I then read all I could find online about dba theory and practical uses, mainly Earl Geddes and Floyd O'Toole material, and it all began to make a lot of sense to me.  I continued to have good discussions via phone and email with James Romeyn and, when he offered a free 30-day in-home trial period with purchase, I decided to give the Debra system a try.
     I think I'll be eternally grateful that I decided to give the Debra a try.  I've posted many times on Audiogon about how well this system has worked in my room/system.  I believe I could write a book about how almost magically the Debra dba transformed bass response in my room and system from mediocre to truly excellent.and, as the 2015 Absolute Sound review accurately stated, provides state of the art in-room bass reproduction.  
     In fact, this concept works so well that I have perpetually felt an obligation to spread the word and sing the praises of the Swarm, Debra and really any "roll your own" dba system on almost any posts that inquires about improved bass response or the 'best' sub to use/buy,  
     I'm fairly certain many frequent thread readers likely know my common refrain by now and roll their eyes when they begin reading another of my bass posts.  I'm generally not too concerned because the truth is the truth regardless of what Trump and Guilliani may say.
     My current opinion is that most readers won't be convinced about how well the Swarm/Debra and custom dbas work no matter how many thoroughly honest testimonials they read from myself and others or even rave reviews on the AK Swarm by The Absolute Sound.  Yet I'm almost certain that just a few minutes of listening to the sota bass response these distributed bass arrays provide in person would convince virtually everyone.  
     Do you notice this discrepancy between descriptions and actual personal auditioning in your experiences? 
     It continually perplexes me, and it must be constantly a bit frustrating to you and James, why there seemingly aren't more users of high performance dba systems, especially by members of a high performance audio site like Audiogon.  I would think they'd be selling like hotcakes and used in many more systems after multiple Golden Ear awards and a rave review along with a Product of the Year award back in 2015.
     Thanks for telling me about your room at Rocky Mountain Audio Fest, I'm going to try to make it out there to see you guys and check out your room.
     Sorry again for my idiotic misstatement, I'm so glad you're still with us!

I wish you a long and happy life with continued prosperity,
    Tim
shoresaudio's avatar
shoresaudio
20 posts
 
@noble100 I like the concept of the DEBRA, but unfortunately have pretty much every inch of wall space accounted for (it's a multi-purpose room--listening room, family room, office), and enough openings for doors that running cables is a challenge. Using bass traps and room treatments for bass is also nearly impossible given the layout. 

But I wanted to experiment nonetheless, and I found two wireless subs from Martin Logan so I could give it a try.  (My main speakers extend down into the upper 20Hz range, the MLs into the mid 20s.)  Given the challenges, I decided to split the output at my preamp and send one of them to a MiniDSP for now, as one of the subs was in a particularly boomy part of the room, and I also time-aligned them to the main speakers.  (The MiniDSP has four outputs, so, I can use up to four subs with it.)  Placement--one is off to the side, and the other is to the side/rear in an opening to the kitchen.

Even with only two subs, it's a major improvement in bass!  My only possible listening position in the room had a major bass suckout, where anything under 60Hz was nothing but wishful thinking.  At first the additional subs were way too boomy, but I kept dialing them back until I thought they weren't even working.  That was the trick.  At the listening seat now, I hear *all* the bass notes in, say, classical or jazz at an even level, much cleaner and deeper than before.  Most of the time, I have to walk over to the subs to make certain they are working--they are that low in level.  The effect also covers a larger area of the room--I'm finding the bass evened out throughout the listening end of the room.

I do plan on adding two more subs and doing this "officially" per the instructions, but even with the two subs, I find it cured a lot of my existing problems in the room.  For not much of a cash outlay, I was able to (roughly) try it and see if the concept would work, and it does.  I'll probably spring for the "real thing" once we move in a few years and I can have a more flexible arrangement in a listening room.  It's definitely worth the investment in time and money.  
noble100's avatar
noble100 OP
2,419 posts
 
Hello shoresaudio,

     Yes, as the owner of Audio Kinesis, Duke Lejeune, likes to say: 
"Two subs will sound twice as good as one. Four subs will sound twice as good as two. And 8 subs will probably get you divorced."

     As you've discovered, the bass response starts to improve (more detailed, smoother and over a larger section of the room.) significantly once you have two subs operating in the room.
    I'm glad you like the results thus far and you should notice another significant improvement going from two to four subs in your new room.   
   I'd just suggest following the sub positioning procedure as closely as you can.  You've already gained good experience realizing how setting the crossover frequency and volume of the subs as low as possible makes the blending of the subs with your main speakers more seamless.     I've been trying to spread the word on how well the 4-sub distributed bass array (DBA) concept actually works and I'm glad you're a new member of the DBA Club.


Best wishes,
     
   
    
jdlynch
62 posts
 
Could a system like the HSU ULS15 quad system be made into a swarm array? 
noble100's avatar
noble100 OP
2,419 posts
 
jdlynch:"Could a system like the HSU ULS15 quad system be made into a swarm array?"

    Hello jdlynch,

      The answer is a definite Yes.  A custom 4-sub distributed bass array (DBA) system can be created utilizing any four subs one chooses. The subs don't even need to be the same brand, model or even size to produce excellent bass performance results in virtually any 
     In fact, a custom DBA consisting of four HSU ULS15 quad subs would certainly outperform an Audio Kinesis 4-sub Swarm/Debra complete kit DBA in bass power and dynamics as well as likely at least matching it in bass smoothness and integration with your main speakers.   It may even equal the Swarm or Debra bass speed and detail, too, but I'm not certain.
     The main downside of a custom DBA, utilizing four conventional self-amplified subs, is that the three main settings (volume, crossover frequency and phase) would need to be set optimally for each sub individually rather than once for all four subs optimally as a group on the included sub amp/control unit with the Swarm/Debra complete DBA kit.  
     I don't know the price of four Hsu ULS15 subs so I don't know if it has a price advantage over the $3K price of the Swarm/Debra DBAs but it does have the advantage of being wireless.
     Based on my sub experience with Magnepan main speakers, I can state with certainty and in general that 2 subs sound twice as good as 1 and 4 subs sound twice as good as 2.  I believe the threshold for attaining near state of the art in-room bass performance in any room is reached by deploying 4 optimally positioned and configured subs.  Fewer subs can definitely perform very well but the bass will likely be compromised and not optimized in all bass performance qualities. 

Tim
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