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.



128x128noble100
I run these systems:

1. Biamp: Acoustat Model 2 (modified panels) with Acoustat servo amps (direct drive, no transformer interface) driving the panels, Beveridge RM-3 active crossover (100 Hz 4th order Linkwitz-Riley high and low pass filters), Luxman M-02 powering the woofers. So the panels play everything over 100 Hz and the woofers 100 Hz and below.

2. Biamp: Same as above except Quad ESL-57 powered by Atma-Sphere M-60s.

I also run the ESL-57 and M-60s without biamping and the bass is quite good in that set up as well.
Hello amg56,

     Welcome to the party.

     The reason I, and I think  the other users of 4 sub distributed bass array systems on this thread, have not mentioned or discussed their main speakers and amps is because we understand it's irrelevant; this concept performs and integrates exceptionally well regardless of the main speakers  and the amp(s) driving them.                 

     My system is a fairly good example of this benefit.  My main speakers are 6 x 2 foot Magnepan 2.7QR planar panels driven by a pair of 1,200 watt class D mono-blocks.  Planars and electrostatics are considered to  be 'fast' speakers that are difficult to integrate conventional subs with because they' usually are much slower, have difficulty keeping pace with 'fast' type speakers and the bass tends to lag behind, making the bass sound disconnected and poorly integrated with the mids and treble from the 'fast' main speakers. 
     The Debra system I use integrates seamlessly with my mains panels both with music and ht.

I hope this cleared things up for you,
  Tim
Thanks for the awesome and informative post! I started on another thread discussing woofer size and followed your link here. Great info and nicely presented.
You got me thinking...! I’m a little unclear on the amplification end though. Forgive me, you probably clearly addressed this but I got really focused on the acoustical aspects and now instead of re reading I’m being lazy and asking.haha Does this involve a special and dedicated amp or a receiver equipped with the technology? I remember reading "any four subs" ; does that mean the size and type don’t matter?
My room is kind of small. It’s 14×22 but due to doorway/closet configuration I’m forced to orient front/rear on the 14’ and only able to use 16’ of the 22’ for speaker placement and that leaves 6’ of space on the left channel which is sonically killing me!!! This (one of a few ) system is in the main living room and therefore used for music and theater. It mainly consists of an older and higher end Onkyo THX 5.1 reciever, Definitive BP-2000 (each speaker has its own powered 300 watt 15" sub) mains, Definitive surrounds, an Atlantic Technologies center (that I couldn’t be happier with!) and until recently a high end Polk 10" sub that was tuned to its lowest (until recently) pass. I couldn’t understand how I blew it up until reading your post and I’m not at all unfamiliar with acoustics but you described exactly what I believe happened! I guess I should have mentioned that I recently moved in to a new home... After setting up the system and being nothing but disappointed I started trying different tunings and settings...no matter what I did/do I’m disappointed in a system I have loved for years! Now I know after reading your posts that the dynamics of the room were cancelling out frequencies that I knew were missing so I just kept feeding it more power and turning the crossovers up until the Polk could take no more even though there was no audible distortion.
Sorry for rambling on, ultimately my question is about the amplification and do you know if I could incorporate my main speakers as part of the array or is that 6’ void in my available space going to wreak havoc no matter what I do? The mid and high frequencies sound perfect as they are directional but I’m a full range fanatic and I NEED my bass! If I could afford them I'd have subs that went all the way to 14htz even though you can't hear it, you can feel it!  In the past I had a perfect blend of pop and boom but now it’s completely lack luster...

Here is the amplifier used in the Swarm/Debra set up. You just need 4 passive woofers to connect to the amp.

https://www.parts-express.com/dayton-audio-sa1000-subwoofer-amplifier-rack-mountable--300-811

I use a different set up as described in one of my posts above, but the objective is the same.

Also, I built my own woofer boxes and bought off the shelf 8" drivers. My goal in a 12 x 20 room was a more compact footprint for the woofers. Then for aesthetics I had the boxes painted with Jaguar black automotive paint.

magzxi,

Sorry, I just noticed your post requesting advice from 8/19/18.

But it looks like clio09 covered for me with accurate info on the amp supplied with the Debra system.

Yes, the 15" subs built into your BP-2000 main speakers would count as 2 of the 4 subs used in a custom DBA (distributed bass array) system. But there’s a specific setup process you need to follow for best results that I can explain to you later.

You’ve stated the mid and high frequencies sound perfect to you in your current system setup. This is very good but I need answers to a few questions before I can help you further:

1. Do you have only 1 listening and viewing position/seat in this room or multiple seating positions?

2. Do you plan to build or buy the additional 2 subs required? Remember, the Dayton amp requires 4 Ohm subs, not 8 Ohm.

3. Is there anything along the 2 long side walls and shorter back wall in your room?

Tim