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.



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Damn!!!! 

Thanks for the replies! 
I just typed a mini novel and when I hit post it went away!!!! GRRRRR!!!! HAHA! 
  I'm out of juice,  I'll try again tomorrow.  Thanks!!! 
I just realized that "post" and "help" were too close together and fat finger struck again! Haha! 
Thanks for the help! I've read the thread over again quickly and don't see the difference between SWARM and DEBRA. What am I missing???   
 
It seems as though any good sub amp could be used. Is that correct?  

Thanks Tim, to answer your questions in order...
1)  There are two couches and one recliner in the room. I have a sweet spot and everybody else gets what is left! Haha! 

2)  I'd have to do some serious research about that! First of all I'd have to wire the BPs passively which is forsaking a 300w rms class a/b amp on each speaker. The BPs dig all the way down to 15hz as they are. I'd want to be able to match that with the DEBRA. The other two speakers... good passive subs are not hard to build but if I could find a nice set of equal caliber for the right price...

3)  As for the room dimensions it sounds like you are interpreting them 90° out of actual orientation. The long walls are front to back and the short walls are left to right. That automatically sucks but to suck it up even more; due to passageway and door configuration there is a 5' unusable space front to back on the left side!  That's what is killing me!!! Highs are directional frequencies while lows are omni directional and radiate from an epicenter as you know so that void on the left is KILLING my bass response! What intrigued me about your post was the explanation of how these unequally refracted bass frequencies could cancel each other out.  I can attest! 

Thanks for your help Tim! 
Ha!!! I was closing old windows and found it! Score!!! Haha! 
Thanks again!!!
"Thanks for the help! I’ve read the thread over again quickly and don’t see the difference between SWARM and DEBRA. What am I missing???"

"Hello magzxi,

The AK Swarm and Debra dba systems are basically identical. The Swarm is retailed by AK founder and owner, Dick Lejeune who I believe passed away in 2017, and the Debra is retailed by his associate and AK dealer, James Romeyn, founder and owner of James Romeyn Music and Audio LLC. If interested, I’d suggest calling James Romeyn in Utah to verify I’m not missing something. and if he sells both now They both look the same, perform equally well,are the same price and I believe have the same setup procedures.

" 2) I’d have to do some serious research about that! First of all I’d have to wire the BPs passively which is forsaking a 300w rms class a/b amp on each speaker. The BPs dig all the way down to 15hz as they are. I’d want to be able to match that with the DEBRA. The other two speakers... good passive subs are not hard to build but if I could find a nice set of equal caliber for the right price..."

You can still use the 300w class a/b amps and subs in each of your speakers. These would count as 2 of the 4 subs required in a custom dba system you’re considering.
You could research the subs used in your BP speakers and try to find a source to buy j the same drivers and build your own subs, even possibly buying a similar plate amp for each (instead of building passive subs and using the Dayton amp) if you’d like. You could also buy 2 powered subs ( new or used).or buy the Dayton or other sub amp and buy or build 2 passive subs of whatever size and specs you'd like..

The important factor is having 4 subs, they don’t have to be the same brand, size or type. The setup procedure is also important but I can explain exactly how to locate your subs once you make a decision on the above.

"3) As for the room dimensions it sounds like you are interpreting them 90° out of actual orientation. The long walls are front to back and the short walls are left to right. That automatically sucks but to suck it up even more; due to passageway and door configuration there is a 5’ unusable space front to back on the left side! That’s what is killing me!!! Highs are directional frequencies while lows are omni directional and radiate from an epicenter as you know so that void on the left is KILLING my bass response! What intrigued me about your post was the explanation of how these unequally refracted bass frequencies could cancel each other out. I can attest! "

Yes, I was misinterpreting your system configuration but now understand the long walls are front to back and the short walls are the side walls ( my 23 x 16 ft room is configured short walls front to back and mistakenly thought your’s was the same.) As far as bass response, either way will result in great bass response as long as they are properly positioned according to the 4 sub dba recommended positioning procedure. I’m not certain, but I don’t believe the 5’ of unusable space will negatively affect the bass response. You already stated that you’ve got the more directional mid and high frequencies sounding very good so you should be good if the bass response improves.

You just need to decide what 2 additional subs to buy or build and how to power them.
Tim