Audio Kinesis Swarm Subwoofer Awarded 2019 Golden Ear Award by Robert E. Greene

Hello Hans,

     I was just wondering how you're progressing on your Swarm system in your office.

Thanks,
   Tim

Here’s what a wrote on my first post on this thread:
" Congratulations again on your extremely well deserved awards, Duke and James. I highly recommend the 4-sub DBA concept and system to anyone wanting sota bass response in their systems and rooms. Since these systems will work seamlessly with any main speakers, you’ll never need to buy another sub system again, even if you switch main speakers or use very fast planar-magnetic or electrostatic main speakers.
I’ve stated this many times before but it’s the honest truth; I’m constantly surprised that more individuals don’t know about how effective DBAs are and that more don’t use one, especially members of a high quality audio site."

I just confirmed the part I stated about " these systems will work seamlessly with any main speakers, you’ll never need to buy another sub system again, even if you switch main speakers or use very fast planar-magnetic or electrostatic main speakers."
I just bought a pre-owned pair of Magnepan 3.7i speakers from a local shop and traded in my almost 25 year old pair of Magnepan 2.7QR speakers that were still going strong and sounding good.
I just had to connect the 3.7is, position them about 8’ apart from each other, with a slight toe-in and the true ribbon tweeter sections on the inside to optimize the mid/treble and dial in the imaging at my listening seat about 12’ away and I was all set.
The only thing I needed to adjust on my Audio Kinesis Debra 4-sub DBA system was to slightly decrease the volume and crossover frequency settings on the supplied sub amp/control unit and the bass seamlessly integrated with the 3.7i just as it did with the 2.7QR.
All 4 subs remain in their exact same positions and there’s still no bass room treatments or room correction software/hardware utilized. I’m fairly certain the AK Swarm or Debra 4-sub DBA systems would still provide excellent in-room bass response and seamless integration regardless of the main speakers I chose and whether or not I changed rooms. Although I do concede I’d likely need to start anew in sequentially positioning each of the 4 subs and setting the control settings to optimize the bass performance if I’d chosen to utilize traditional dynamic main speakers.
Just thought readers would like to know that claims of the 4-sub DBA concept working equally well with any pair of main speakers and in virtually any room are not exaggerations.

Thanks,
Tim

"I guess speakers that are weak between 80 and 140 are not very common ..." 

I agree, not very common. This was the only such case I have been involved with. 

Duke

I understand very interesting, just the subs closer to the speakers at 140 (because the listener been able to pinpoint their location) and the other 2 at 80 to make it sound more natural, very cleverI guess speakers that are weak between 80 and 140 are not very common or is it?

Luisma31 wrote: "...no no no, with your midbass driver I think the 80 hz works wonderful, actually I run mine 60 below, don’t you dare touch my crossover Duke, sounds perfect the way it is." 

Thank you Luis! 

I was referring to the hypothetical situation where an 80 Hz crossover was not high enough.

One time we were integrating a Swarm with a system that was horn loaded down to 80 Hz, but it turned out that the response started rolling off at about 150 Hz and then the rolloff accelerated below 80 Hz. So we placed two Swarm units near the main speakers and drove them with one amplifier and rolled them off at about 140 Hz, and then the other two were placed much further from the main speakers and were rolled off around 60 Hz. We used the parametric EQ’s to fine-tune the blending.

Something like that would be the work-around if the crossover needed to be higher than 80 Hz. 

Duke

I have frightening dreams about being attacked by a swarm of woofers...otherwise yeh, I get it.

My Swarm is trained not to attack, you have 2 subs? That's heresy :) with your perfect speakers

That being said, there are work-arounds if the need arises to cross over higher up

@audiokinesis no no no, with your midbass driver I think the 80 hz works wonderful, actually I run mine 60 below, don't you dare touch my crossover Duke, sounds perfect the way it is

I use 2 subs and although I think the Swarm is a great idea, I have frightening dreams about being attacked by a swarm of woofers...otherwise yeh, I get it.

" The bottom octave is generally considered to be 20Hz to 40Hz, the second octave 40-80Hz and so on. "
This is what I had in mind when I was talking about "the bottom octave or so".  

I don't normally recommend running the Swarm higher than about 80 Hz because the ear may be able to detect the locations of subs that are well away from the main speakers, and that would be distracting.  That being said, there are work-arounds if the need arises to cross over higher up.

Duke

Thanks Ralph, that explains a lot...

@luisma31  The bottom octave is generally considered to be 20Hz to 40Hz, the second octave 40-80Hz and so on.


80Hz has a bit of a special meaning to subwoofers and the human ear because it is at about this frequency that bass appears omnidirectional to the human ear. This is partially because it takes some time for the ear to register that the bass has occurred. So it does not matter where the woofers are if they are only operating below this frequency; the rest of the speaker system (80Hz and above) provides the location information on those bass notes from their harmonics.

Thanks Tim, I thought the bottom octave was technically 11-22 Hz (not that I can hear anything there), then you have 22-44 Hz and 44-88 HzSo what you guys speaker / audio equipment experts refer to as the "bottom octave" would be as you are describing 32 Hz (possibly what we most can hear) and 88 Hz?

luisma31,

     The bottom octave refers to 16-32 Hz, 32-88 Hz is what is technically  referred to as the 'or so'.


Tim

use the Swarm to fill in the bottom octave or so.

@audiokinesis just checking, this means 88 hz and below right?

audiokinesis:"In my opinion room treatment in the bass region is virtually always beneficial, as the improved damping reduces the magnitude of the peak-and-dip swings."


Thanks Duke.  My room acoustics and GIK products efficacy adventures begin.

Tim

@noble100 wrote: "I was just going to contact you with a question I have about whether room bass treatments negatively or positively effect the performance of the Swarm/Debra bass systems in a given room." 

In my opinion room treatment in the bass region is virtually always beneficial, as the improved damping reduces the magnitude of the peak-and-dip swings.

Duke

Hello Duke,

Another Swarm bass success story that, as an owner of the AK Debra 4-sub distributed bass array (DBA) system, doesn’t surprise me at all.

I’m glad you posted again, Duke, because I was just going to contact you with a question I have about whether room bass treatments negatively or positively effect the performance of the Swarm/Debra bass systems in a given room.
I recently had a free analysis of my room by GIK Acoustics done and they recommended I utilize some of their bass treatment products in my room, mainly the following:


1. Stacked TriTraps in all 4 corners of my room.

https://www.gikacoustics.com/product/gik-acoustics-tri-trap/

2. 244 2’x2’ and 5.25" thick bass trap panels on the floor level of my front 14’ 2" front wall behind my Magnepan 3.7i main speakers.

https://www.gikacoustics.com/product/gik-acoustics-244-bass-trap-flexrange-technology/

     This plan would result in a 2’x2’ Debra sub being located between a 2’x2’, 5.25" thick 244 bass trap panel and the bottom TriTrap located in the corner behind each main speaker which are both positioned about 3’ away from the front wall.
My question is what effect do you think these combined bass room treatments would have on the overall perceived bass response in my 21’x12.2’x8’ room?
     The current bass response with the Debra system operating in my room is extremely good with zero room treatments and room correction in use. My main concerns are doing no harm to the current results and not spending the time and money on these treatments if you don’t believe they’ll have a meaningful positive effect.
     Within a few weeks on a different but related concern, I’m also going to upgrade my about 25 year old pair of Magnepan 2.7QR main speakers, containing quasi-ribbon treble sections, with a pre-owned pair of 1 year old Magnepan 3.7i speakers, with true-ribbon treble sections. Given your considerable experience in speaker design, room acoustics and knowledge of Magnepan speakers, I was hoping you could also give me your opinion on my general plan for utilizing GIK room treatment products to optimize the perceived full range frequency response of the pair of 3.7is in my room.
     The 3.7is will be positioned about 8’ apart, with the true-ribbons on the inside, along and about 3’ away from the front short wall with my listening seat about 12’ away centered on the rear short wall. There’s a 6’ tall x 8’ long window section along the left 21’ long wall, covered by a plantation blind window treatment with 1" wide wooden horizontal slats, that begins about 2’ in front of the left 3.7i and continues for 8’. The right 3.7i is positioned at the beginning of a 4’ x7’ opening at the front of the right 21’ long wall. The remaining portion of this section is a solid wall with no other openings with an 8’ leather couch positioned along it.
     There’s also a wall mounted 65" hdtv centered along the 12’ wall between my speakers and a Magnepan CC3 center ch speaker attached to a smaller tv wall mount that positions it just above and centered on the hdtv beow it.

     My general plan is to use an approximate 50/50 balance between absorption and diffusion GIK treatments throughout the entire room with nothing on the 8’ tall ceiling and the floor covered with fairly thick wall to wall carpeting. There are room pics on my profile page if it helps.

     As I stated, this plan would result in a 2’x2’ Debra sub being located between a 2’x2’ 244 bass trap panel and the bottom TriTrap located in the corner behind each main speaker which are both positioned about 3’ away from the front wall. There will be side by side 24.5" w x 48.5" tall GIK 242 absorption panels, with diffusing scatter plates underneath the top cloth covers and positioned above each bass trap and sub behind each 3.7i.
https://www.gikacoustics.com/product/gik-acoustics-242-acoustic-panel/

     The remainder of my plan is to use an even distribution of absorption, diffusion and combination panels on the remaining solid wall portions on both side walls and rear wall. The goal being to ensure that there’s adequate diffusion of soundwaves at the front and rears of the room to avoid over damping the overall room and sound.
Based on your knowledge and experience, do you believe my overall plan is a good one?
      I really appreciate any help you can offer, I’d like to order all GIK treatments by end of tomorrow, Thursday Dec. 12th.

Thanks,
Tim

Installo43, yeah I don't think I could buy a testimonial like that one if I wanted to!
In your situation I think we'd use essentially the same approach... run the Treo's fullrange, and use the Swarm to fill in the bottom octave or so. 

I have owners of speakers like Wilson and Magico who run their main speakers fullrange and then use the Swarm for the very bottom end.
Duke

Duke,

Thanks for the response! Wow. That is certainly a rave testimonial...and in keeping with all the other things that I have heard about the Swarm.

I guess I should have been more specific about my situation. My application will be strictly stereo, not surround. It sounds as if the customer with Vandersteen Quatros ran the Quatros full range and the Swarm was running simply as LFE...which I see as a very different application.

The question I had was about the best way to integrate the Swarm with relatively full range speakers in a stereo only setup.

"Does anyone here have experience pairing a Swarm/DEBRA with relatively full range speakers...in this instance the Vandersteen Treo’s?"

Installo43, one of my customers has Vandersteen Quatros.

Before getting the Swarm, he had been using one sub and a Meridian processor with 16 of its available 60 digital filters professionally calibrated to smooth his in-room bass response.

He replaced his sub with the Swarm, ran the Quatros full-range with their filters set to neutral, and hired the same (highly experienced) technician to make measurements and calibrate the filters on his Meridian processor. The technician found that the ONLY adjustment needed was to the level of the subwoofer amp. No further equalization was needed, either from the Meridian processor or from the Vandersteen’s analog filters (well, the Meridian did equalize the two surround speakers a bit, but that doesn’t affect what the Swarm was doing). He wrote that the Swarm "had rendered both the Meridian Room Correction and the Vandersteen’s analog equalizers unnecessary" for his room.

Quoting from his e-mail:

"The technician, J___ S____, who has performed dozens of these calibrations, said he has never seen anything like this. The room is rendered literally flat in frequency response and spatial energy distribution - sonically the room disappears. We played one of Kal Rubinson’s recommended demo discs, the 100th anniversary for the San Francisco Symphony Orchestra using the John Adams piece, "Short Ride on a Fast Machine", and you would swear you were in the hall. You can "feel" the ripple in the tympani skins! Very impressive."

I DO NOT claim that these results are "typical", but apparently it is possible to use the Swarm with a set of Vandersteens.

Duke
got a dog in the fight

I find this concept to be fascinating although I have never actually heard it. For many years I have known that multiple subwoofers can greatly smooth the bass response in a room but I haven’t actually experimented with it.

Does anyone here have experience pairing a Swarm/DEBRA with relatively full range speakers...in this instance the Vandersteen Treo’s? The Treo is -3db @ 36Hz.
For those not familiar, Richard Vandersteen has a very specific technique for pairing the Vandersteen subs with his full range speakers. It involves an outboard first-order high pass crossover for the main speakers.(installed between the preamp and amp) The subwoofer also receives this signal from the amp by speaker wire and is built with some sort of low pass first-order crossover and it also somehow equalizes to compensate for the reduced bass level received through the speaker wires. So it results in very gentle 6db rolloffs for the subwoofer and mains either side of 100Hz. I really like this setup and think it works extremely well.

My big question is what would be the best way to setup if I wanted to integrate Swarm/DEBRA with the Vandersteen full range speakers.
-No crossover on the Vandersteens and the 24db crossover on the Swarm/DEBRA at about 36hz?
-A Vandersteen first order high-pass crossover on the mains(100Hz) and a low-pass 24db crossover on the Swarm set at....?
-or some other variation that I haven’t thought of?

@luisma31 If you do have a pre with capacitor coupled outputs, at 39k, you’ll need 2uF of capacitance (or more)... https://www.v-cap.com/coupling-capacitor-calculator.php

First @audiokinesis congrats on this very well deserved award, you guys have changed the way I enjoy music and I was very lucky to find you. Needless to say Duke your altruistic attitude is a quality very scarce these days on this modern world.
Thank you everyone else posting as I actually have noticed a few tricks I could use to improve my AK swarm
Now, @cal3713
Interesting comment, I am using a tube preamp but going 1st to a Jensen balanced to single ended isolator which impedance is 39 kohm, in this case the tube preamp is presented with the transformer impedance not the SA1000's one, need to find out if my preamp have output capacitors.I have been considering splitting my digital source output as today my preamp is feeding my mono's and the Dayton's and when the Daytons are connected the speakers connected to the mono's changes sound, maybe because of the impedance change. This will allow some digital filtering sending 60 Hz and below to the Daytons and 60 Hz and above to my monos (need to ask Duke about the exact frequency as I also have his speakers)

Just a quick note to those using the Dayton sa1000 to drive their subs. It has a very low input impedance, 12k ohms. If you're driving it with a tube preamp with output capacitors, you'll need a cap at around 6-7uF to avoid rolloff above 20Hz.  I had to order some new caps to fix that issue, still, it drives my subs amazingly.

Hello davekayc,

    Congrats and welcome to the DBA Concept club! Even in your huge room, I don't think there's a need to go beyond 4 subs but, otoh, 6 subs is...… extremely cool.  
    Each sub beyond 4 will not only marginally increase the perception of the bass as being smoother, faster, more detailed and natural, it will also increase the overall perceived system bass quantity, impact and bass dynamics.  
    You are now officially a member of the esteemed 4-sub DBA Concept club. Having automatically earned this coveted honor upon utilizing 4 subs in your room and system, you nevertheless bravely ventured forward into unchartered bass territory, beyond state of the art bass, by continuing to deploy additional subs #5 and 6. That my adventurous and intrepid grasshopper, is definitely worthy of at least another superlative, nice job!


Venture forth and prosper,
          Tim

I have 6 subs aligned now . And i can see the benefit of more of them. I set them in the obvious spots as per Tims suggestions. Unreal. I could see having 2 more still. Especially being it is a large room and they have to all be set quite low compared to the mains. The effect is there but not boomy if you walk out of the sweet spot. 

Here is how Greg Weaver of Enjoy The Music describes our Sextet/Swarm demo in his CAF 2019 show report:
"The Sextet is an ambitious speaker system that is a collaborative effort, building upon the Tubulous technology from Gingko Audio, the Swarm subwoofer system from AudioKinesis, and unique cabinet construction from Salk Sound. Leveraging the 1-inch soft dome tweeter and 6.5" paper-cone woofers used in both the Gingko Audio Clarissa and ClaraVu speaker systems, the Sextet is a fully configurable system that can be purchased as just the Sextet 2 (the pair of Sextet monitors - $4,995), the Sextet 2+2 (the monitors and two dedicated stands - $5,795), or with various combinations of the subs, including the full Sextet 6.2 (using two monitors, two powered subs – which also act as monitor stands, and two outboard subs – $8,995). The subs have switchable polarity, 0° and 180° to better integrate and help manage constructive or destructive interference.

The tremendous versatility here is that users can start with just the monitors, and later, as budget or space permit, add a pair of subs (Sextet Swarm 2-One powered sub with built-in amp and one passive outboard sub $2,000) which can be used as stands for the monitors, and/or then add the second Swarm sub system for the full Sextet 6.2, to maximum effect.

Vinh's demo was impressive, using the 6.2 system set up at follows. The left Sextet monitor was mounted atop a powered sub, with its mated outboard sub in the front right corner of the room. The right Sextet monitor was mounted atop the second powered sub, with its mated outboard sub in the rear left corner of the room.

Vinh now played a track with just the Monitors on. The sound was smooth and engaging but didn't really fill the room or convey the space and power of the music. Next, he turned on the left powered sub mated to the outboard sub in the front right corner of the room, then he played the same track. Knowing what to expect, I loved seeing the reaction from all the listeners in the room who may have not been familiar with what this would do. The look on most of the faces in the room was one of almost incredulity, of unbelievability!

Not only was there more bass fueling impact and weight, but the space of the recording completely opened up, filling the room, with more honest timbre and more realistic, three-dimensional staging. Finally, he turned on the right powered sub and its mated rear left outboard sub and started the same track yet again. While this was the more subtle of the two reveals, it was still handily impressive. More of everything, more weight, more space, more accurate tone and texture, more detail and dimension.

This was a masterful demo; one that clearly demonstrated why you need the extension provided by a full range speaker or a well-mated satellite/subwoofer system. It is not just deeper, more pitch defined, impactful bass, but the addition of the bloom and body, the more correct voicing, and the expansive space and dimensionality that it affords. I truly wish more people would demonstrate this effect. As such, my hat is off to Vinh, and the Gingko team. I hope they see wild success with this superbly versatile and enjoyable Sextet speaker system."

haywood310:
"The "Earl Geddes" effect done right is just SPOOKY! It takes all of your rooms weakness’s and makes them work against each other push/pull, Yeng Yang, Women are from Venus and Men are from Mars. Good bass is not just about pounding AC/DC although it can do it right. More importantly it will bring your highs, mids, and sound stage depth to a new level. Like plannars Maggies or Soundlab stats done right. It is just hypnotic and SOOOOO much better. Im trying to get that with Kinergetics SW 800s right now and asking for advice. But I will be using 26 10 inch woofers instead of 4. I have heard the Audio Kinnesis system and it is simply amazing. I just happen to like AC/DC and hate my neighbors Haha. "

Hello haywood310,

You’ve experienced the Earl Geddes inspired 4-sub distributed bass array (DBA) concept that Duke Lejeune and James Romeyn of Audio Kinesis have developed into their Swarm and Debra 4-sub DBA complete kit systems. Having used the AK Debra 4-sub DBA system in my system and room for about the last 5 years, I completely agree with your description of the bass performance results as SPOOKY good. I would just add to your colorful description of the way it works to explain my understanding of the degree that adding subs actually increases the bass sound quality in virtually any given room:

To summarize PHD Dr. Earl Geddes’s scientific findings that were later developed into the more practical 4-sub DBA concept and product by others- In virtually any given room, 2 subs will produce bass that sounds about twice as good as 1, 4 subs will produce bass that sounds twice as good as 2 and each sub added beyond 4 will only result in producing bass sound gains that are smaller in magnitude and more marginal. This is the reason the AK Swarm and Debra systems utilize 4 subs.

As far as your requested advice on how to get the same bass quality performance gains that a 4-sub DBA provides by utilizing your Kinergetics SW-800s, some advice I can offer is that there are obstacles you’ll likely face in your endeavor.
You stated that you’ll be using 26 10 inch woofers instead of the Swarm’s typical 4 10 inch woofers, one per sub cabinet. It’s my understanding that the Kinergistics SW 800 are sub towers that each contain 5 10 inch woofers arranged vertically. Does this mean you have 5 SW- 800? If so, this would equal 25 total 10 inch woofers(5subsx5 woofers each=25), Where does the extra 26th 10 inch woofer reside? In a separate cabinet as a discrete additional sub?
I’d like to advise you on how to optimize the bass performance in your room using your SW-800s but I first need your answers to the above questions to do so effectively.

Thanks,
Tim

To follow up on Duke's post, we did feature the Gingko Audio Sextet at CAF earlier this month.  We gave a demo to illustrate the effect of the Swarm concept by just playing the monitors first in a large conference room (35x22x10), then adding two subs (one powered and one passive), then another two, playing the same music track.  The effect was very noticeable by all attendees.  Here are some impressions that were posted about the rooms (we had two rooms at the show, the bigger showcased the Sextet):
“Gingko Audio had for me, the most realistic soundstage with their Sextet speakers that include 2 monitor speakers and 4 subs in a swarm arrangement. Excellent imaging, and the bass was spot on.” Rusty on Audio Circle

“There were two rooms running Ginko speakers and both systems were very good sounding. One was a $10,000 system running in one of the big rooms which sounded beautifully balanced, natural, and relaxed, without sounding lifeless. The small stand-mounted speaker in another room (I think it was $3,000) sounded very good too-very well balanced and natural sounding.” Larryi on Steve Hoffman Forum

“Gingko audio had small speakers in a small room and bigger speakers in a big room. I only spent a small amount of time in each room, but they both accomplished the naturalness and dimensionality that hits me hardest when it's there and leaves me least engaged when it's not.” willsw on Super Best Audio Friends

Thanks to Duke again for his very generous sharing of his expertise in designing the Sextet subs, kind of a Mini-Swarm version.

Vinh Vu

Gingko Audio

The "Earl Geddes" effect done right is just SPOOKY! It takes all of your rooms weakness's and makes them work against each other push/pull, Yeng Yang, Women are from Venus and Men are from Mars. Good bass is not just about pounding AC/DC although it can do it right. More importantly it will bring your highs, mids, and sound stage depth to a new level. Like plannars Maggies or Soundlab stats done right. It is just hypnotic and SOOOOO much better. Im trying to get that with Kinergetics SW 800s right now and asking for advice. But I will be using 26 10 inch woofers instead of 4. I have heard the Audio Kinnesis system and it is simply amazing. I just happen to like AC/DC and hate my neighbors Haha. 

@noble100 Thanks Tim. I'm definitely considering it.  

Hello cal3713,

     Thanks for the tip on sorting.  Fortunately, it looks like today everything's back in normal order.  Maybe it was just an IT issue that they fixed.
     I'm glad you got your Coincident sub cabinets working and integrated well with your main speakers.
     If you have the time and inclination, I'd suggest that even higher quality bass performance and more seamless integration with your main speakers can be obtained by adding 2 subs to your system.  All you'd need to create a custom 4-sub distributed bass array (DBA) system in your room is to use 2 additional subs with 10 or 12" drivers and position each using the crawl method.  The main obvious benefits would be greater bass detail, impact and dynamics along with a seamless integration with your main speakers.  
     The 4-sub DBA concept works incredibly well in virtually any room and with any pair of main speakers.  I know you'd be very pleased and amazed if you give it a try.



 
     
     
 

@audiokinesis Also, I just wanted to thank Duke for being so open and upfront about what he does and the products he uses to build the swarm.  Based on his postings, I purchased a pair of the Dayton Audio SA1000 subwoofer amplifiers to try on my Coincident Pure Reference Extreme subwoofer cabinets.  

Over the past year and a half I've struggled mightily to extract bass from these speakers despite using many different amplifiers ranging from 8 - 250 watts (and 300B SET, Class A, OTL, and Digital topologies).  Adding in the Daytons on the subwoofers was a revelation that finally allowed me to hear them as designed. 

I'm using a 25W DIY First Watt F4 (or SIT3) on the head units and the 500W Daytons on the subs and they finally sound like the reference speaker they're supposed to be... and I am not losing imaging coherence as I have in previous attempts at biamping.  The adjustments on the sub amps have allowed me to nicely dial them in for system matching.  Not a ton of Coincident PRE owners out there, but I think anyone with this speaker simply must try out the amps to see what they're missing/getting with their current amplification.  The 45 day trial period makes it risk free.

Thanks for posting Duke, I so appreciate what you bring to the community.

@noble100 Hi Tim, I've got a "sort" option at the top of the thread that allows you to flip the order back and forth from "most recent first" to "oldest first."

Hello all,

    Well, my first test post today, 11/17/19, confirms that Audiogon seems to have a system malfunction that places the most recent post on a thread first sequentially which is the exact opposite of how post sequencing has been handled here previously for years. 

     Did I miss the notice that Audiogon decided to change the sequencing of posts?  If so, somebody made a real bone-head decision that suddenly throws a huge monkey wrench in their forum functionality. 
    I find it hard to imagine the administrators of this forum would be this dim-witted but I'll need to wait and see.

Tim 

Hello all,

     I was following this thread but it now seems like something mysterious happened to make it somehow be out of sequence and therefore no longer easy to follow.

    I posting this on Sunday morning on 10/17/19 just as a test to find out sequentially whether it is placed properly.  If it's properly placed as the last and most recent post, perhaps this post can serve as a marker so we can then continue this thread's discussion in a normal subsequent progression, meaning one after the next with the last post being the most recent.
     We shall see.

Tim

     

@davekayc - Did you place the sub up on the listening chair itself or on the floor where the chair would be located? Interesting (and clever!) that placing a sub down the stairwell enhanced impact of the lower bass. 

I went around my room today with one sub running a 30hz tone placed in the listening chair . I went around the room and identified all the hotspots with an iphone app like a spectrum analyzer. I like being able to reach around high and low to see actual numbers and readings.  Directly behind my seating area there is a wide  stairwell going downstairs .  I found a few 30hz hotspots down there. I put one sub there to try it . It really brought up the deepest bass impact without a ton of volume. Placing the sub as Tim suggests in the listening seat is a must . The whole  room is your subwoofer after. Its amazing what even one 10” is capable of with accurate room placement . I’m starting to think my dual 18” could have been more 10” instead . Although the nice part is i can dial them back and still achieve 20hz with authority.
 Been a very eye opening topic. 

@c_morris999 +1

Agree 100%!  noble100 has always been very forthcoming with detailed and thorough explanations. I now understand the basics behind the major advantages afforded by the DBA concept.  

It really does make sense. 

millercarbon is another great resource as he has built his own DBA system from scratch and is also very knowledgeable.  Learned a lot from him as well.

My listening room is a small office 9 x 11 with no floor space to spare and there was no way I was going to practically fit in a sub (let alone four of them!).  It just would not work.  I did not place an order.

Then about a week ago I read a post earlier in this thread from Duke mentioning that 2 or 3 subs can be mounted up high facing the ceiling. 
  
I called Duke from AudioKinesis (who was very accommodating and patiently spent a lot of time on the phone with me answering all of my newbie questions while giving me a mini education in acoustics) and ordered the Swarm in black finish.

Duke also explained that in addition to saving floor space in a small room, ceiling facing subs help with the vertical plane (don't ask me to explain) in most room sizes.

Duke also mentioned that the two subs on the floor (one under each main speaker) can be placed facing any direction and not necessarily right up against a wall.  

Now I can have two subs up near the ceiling and the subs under each main speaker will not take up any additional floor space!!

He said I might want to experiment with just one ceiling facing sub, one sub under each main and the fourth sub under my desk.  Perfect for a foot rest with the benefit of one less shelf to mount up high on the wall.

Now that's versatility!! 

I will post results after setting things up. Would be interesting to compare setup notes/results with other Swarm/DEBRA/Custom DBA owners using them in small (or any size) rooms.

Hans

@noble100 - thanks so much for the detailed and thorough response. I think I got caught up in setting up each sub in a symmetrical manner, rather than optimizing the position using the crawl method. I also tried to set them up without the main speakers running, which negated the bass output from that they provided. I will follow your guidance and let you know how it goes :). Thanks again.

Chris

I just wanted to make it known that, in addition to Jim Romeyn's DEBRA which differs from my Swarm in footprint (his is rectangular, mine is square), Vinh Vu of Ginko Audio offers a slimmer and trimmer Swarm-type system as part of his Sextet, which was introduced at Capital Audio Fest a couple of weeks ago: 

https://www.ginkgoaudio.com/2019/09/12/introducing-sextet-speaker-system/ 

Vinh is using two of the subs as speaker stands in that system, which works very well with his patented Arches resonance-control support system.  The Arches add stability without adding visual mass, as you can see at the link above, and can be used on a regular Swarm or Debra set as well, especially if two of them are going to double as speaker stands.  Jim and I will be offering the Arches as an option. 

Just for the record, I don't get a kick-back from Sextet subwoofer sales. Vinh paid me in Arches for my design work (it was a collaboration but I did the math with the same target curve in mind as for the Swarm and DEBRA). 

Duke

davekayc:
"Most every frequency had a standing wave in a slightly different location from each other . But most landed where i had each of the rear subs. (Rear subs off )  sound right to you tim ?  Felt like i should be putting them in the obviously quiet spots . A couple spots would almost cancel out."


Hello davekayc,

     Yes, it sounds exactly right to me.  The reason there were bass standing waves, and noticeably poor bass performance at the rear of your room, was because you only had the 2 front subs launching bass soundwaves into the room if you turn off the rear 2 subs.  But this makes perfect sense to me given my understanding of the 4-sub DBA concept.
     It's important to understand that having 4 subs well distributed throughout your room and launching bass soundwaves is the key ingredient of the 4-sub DBA concept and the main reason it works so well in virtually any room.  Reaching the threshold of having 4 subs launching bass soundwaves into the room is not an option but a requirement.
     The way it really functions is a bit counter-intuitive and involves psychoacoustics.  The 4 subs actually significantly increases the number of bass modes ( spots in the room where both directed and reflected bass soundwaves meet at various angles and cause spots of bass exaggeration, attenuation and even cancellation) existing throughout the room.  However, our brains process the presence of these numerous bass modes by summing and averaging the bass information by frequency and this rather unexpectedly creates the perception that the bass is very smooth, fast, detailed and natural.  This process is referred to as psychoacoustics.
     By turning off your 2 rear subs, the overall quantity of bass modes existing in your room is significantly reduced and your brain is only summing and averaging the smaller number of bass modes existing in your room which is not sufficient to create the perception of smooth, fast, detailed and natural bass. 
     You're stating you mainly detect poor bass performance at the rear of your room with your 2 rear subs turned off.  I believe if you made a more thorough sound quality canvassing of your entire room, however, you'd likely detect poor bass performance at other specific spots in your room.
     Overall, I think you've done an excellent job of creating a high quality custom 4-sub DBA system in your very large room with seemingly little assistance.  Congratulations and enjoy.
     I'm achieving the same excellent bass quality and soundstage imaging results you described in my 23' x16' x8' room and have been enjoying it daily on both music and HT.  I think it's important that readers of this thread realize that the 4-sub DBA concept is capable of providing these excellent results in virtually any size room.  
     I feel it's also important for all to know that buying a complete Audio Kinesis Swarm or Debra 4-sub DBA system for $3,000 is convenient but not the only option, custom 4-sub DBA systems can be created using any 4 subs properly positioned and configured.  The 4 subs don't even need to be the same brand or model and individuals can buy the same 1K watt Dayton amp from Parts Express (usually for about $300-$500) and build 4 DIY subs if they'd like.

Later,

Hello c_morris999,

     The 4-sub Swarm DBA system requires no equalization, bass room treatments or room correction. Just follow the sequential positioning procedure for each sub, one at a time, until all 4 have been optimally positioned in the room. Once all are positioned, there are controls on the supplied amp/control unit that that are done once and effect all 4 subs equally as a group. The controls on the amp/control unit that need to be optimally set are Volume, Crossover Frequency and Phase. I can explain in detail how best to set these but it’s not relevant right now to answer your question.
     Your scenario, attempting to optimally position and configure a 2 sub bass system requires a different procedure. Best practices calls for first using the crawl method (google it) to optimally position each of your independent subs, with independent volume, crossover frequency and phase controls existing on each sub, in relation to your listening seat for each sub sequentially. Here’s a good procedure for you to follow:

1. Set sub#1’s volume control to about 50% (12:00 on the control), the crossover frequency control to the lowest rated bass frequency your main speakers are capable of producing and the phase control to in-phase (’0").

2. Hookup sub#1 and position it at your listening seat location and play some music with good and repetitive bass at a medium volume level.

3. Starting at the front right corner of your room, begin slowly walking or crawling on your hands and knees around the perimeter of your room in a counter-clockwise direction until you find the first exact spot in your room that the bass sounds best to you (solid, smooth, fast, detailed, dynamic and natural). Once you identify this exact spot, reposition sub#1 to this position.

4. Hookup sub#2 and position it at your listening seat location and, with sub#1 playing at its new position, play some music with good and repetitive bass at a medium volume level again.


5. Starting at the new position of sub#1, continue slowly walking or crawling on your hands and knees around the perimeter of your room in a counter-clockwise direction until you find the second exact spot in your room that the bass sounds best to you (solid, smooth, fast, detailed, dynamic and natural). Once you identify this exact spot, reposition sub#2 to this position.

     At this point, both subs should be optimally positioned in your room. To verify, sit at your listening position and once again play the music with good and repetitive bass. If the bass sounds very good to you and is very well integrated with your main speakers, then the optimum positioning of both subs in your room has been verified. If not, you’ll need to repeat this procedure starting with step #1.

     Once both subs have been verified to be positioned optimally in your room, this very good bass response performance in your room can be even further improved, or fine tuned, by optimally setting the Volume, Crossover Frequency and Phase controls on each of your subs individually.
To perform this bass fine tuning in your room you have 2 options:

Option#1- Do it manually by ear and to your preference by recruiting an assistant; with you sitting at your listening seat and music with good and repetitive bass again playing, the assistant can adjust the 3 available controls (volume, crossover frequency and phase) one control and sub at a time at your direction until you’re completely satisfied with the results.

Option#2- Do it automatically by running the room correction function on your subs one at a time and individually.

     For best results, I recommend performing both options and utilizing the resultant control settings that you think performs best. Based on personal experience with different brands of subs than yours, I’m virtually certain each option will result in different combinations of settings and one option will provide clearly superior results.

     If you follow my instructions above, I’m very confident you’ll be pleased with the bass performance of your 2-sub bass system in your system and room. You’ll also have the future option of adding 2 more subs of your choice and creating your own custom 4-sub DBA system that would likely equal or even surpass the near state of the art bass performance of the Audio Kinesis Swarm or Debra 4-sub DBA systems. 
     The only disadvantage of a custom 4-sub DBA is the need to set the 3 crucial sub controls (volume, crossover frequency and phase) individually for each of the 4 subs rather than once for all 4 subs as a group on the Swarm and Debra DBAs.

Hope this helped you,
Tim

Yes Tim 
two 18” and two 10” .  In front of the 18s requires no augmentation from the 10” Its what they do for the rest of the room. By having them faintly adjusted so they are invisible to point at, creates sort of a swarm effect in areas that felt outside the sweetspot . More like you were at a live cabaret setting or even small concert venue . You are standing outside of the listening center or the imaging of left and right but none the less placed in the middle of the venue.  The listening chair  is dead center of the room in every way aimed at the middle of a 56 x15 wall . Kitchen to the far rear left bar to the far rear right . So i still have the makings of a “swarm idea” i just do not have all the subs running at the same output as the fronts .The effects of that would be undesirable for the rest of the room. They are connected to output 2 on my c46 . I can shut them on and off from my chair. I will try them adjusted up to reach the center seating tomorrow and report back. Tonight i played test tones with tidal to see how different frequencies acted in the room. 
Most every frequency had a standing wave in a slightly different location from each other . But most landed where i had each of the rear subs. (Rear subs off )  sound right to you tim ?  Felt like i should be putting them in the obviously quiet spots . A couple spots would almost cancel out. 

Thank you all for the information provided. I have two Syzygy SLF 870 12" subs, matched to Emerald Physics EP 4.7 open baffle speakers. I am interested in the Audio Kinesis Swarm concept and have a question. The subs have an eq function which works well, but only independently. In other words, I can't set up one sub, and then use equalization on the other sub taking into account the bass output of the speaker and other sub. Is it better to use both subs without the room eq, place them in different locations and adjust the individual crossovers and output level by ear? Equalizing them independently doesn't seem to be consistent with the "swarm" concept. I am having trouble integrating the subs with my EP 4.7s, which are running full range. Thoughts? 

Hello davekayc,

     Are you stating you're using 2 Greg Timbers designed 12 cu.ft.  sub cabinets with an18" JBL 2245h driver in each as DIY main subs and you're also using 2 JBL sp-150 subs for a total of 4 subs in your room?
   
Thanks,
  Tim  

Oddly enough my room is 56’ and 36’ deep . The waves can stretch their legs in here . After a day of listening and adjusting,  my main system included , I’m pretty happy with the sound . Soon as particular types of music come on I tour the room listening for the effects . I want a seamless integration of all components , anything less will drive my crazy. I do not want to be able to tell they are there. Right this minute i am listening to Robert Plant , In the Mood .  Very good track for repetitive bass notes with out extra sounds confusing things. Sound via a mcintosh mr78 tuner . My favorite station has the odd station identification that dips into the subsonics which all in all its a good place to get your bearings from. After I’m done tweaking i will turn on tidal with bluesound and see how i did. Try out a few ridiculous bass tunes . As well they have a selection of test tones .    My main subs are 12cuft 18” jbl 2245h , the enclosures are a greg timbers design . Powered by two mc2300 amps. I had divine bass response already . The rear subs really evened out the sound . As mentioned before i no longer feel the need for room treatments . It improved the highs reminiscent of the days when i built car audio systems in the late 80s .( jbl / harman amps ) You are in it, and not a bystander.   Thanks again Tim 

Hello davekayc,

       I'm guessing from your huge room dimensions that you live in a loft.  I've learned that getting the bass right in most home rooms is a key factor in building a high quality, realistic home audio system but it's also usually the hardest part of the audio spectrum to get right.  
     Most people can very quickly tell the difference between music heard in person played live and the same music played back via a recording on a home audio system.  I believe bass that is felt as well as heard, detailed, textured, solid, impactful and with a powerful dynamic range, basically bass that has the qualities of bass played live and heard in person, is required to be replicated on a home audio system in order for the experience to be perceived as realistic and of very high quality.  
     The main reason good bass performance is so difficult to obtain in most domestic rooms is that bass soundwaves behave very differently than midrange and treble soundwaves behave in any given room.  Here are some important facts to understand and keep in mind:


1. Humans generally have an audible hearing range from deep tones to high tones of 20 Hz (deepest tone) to 20,000 Hz (highest tone).

2. The deeper the tone, the longer the corresponding soundwave produced.  The higher the tone, the shorter the corresponding soundwave produced.  For example, the full cycle soundwave length of a very deep 20 Hz tone is 56 feet and the full cycle soundwave length of a very high 20,000 Hz tone is only a fraction of an inch.
     It's also been proven that the entire length of a full cycle soundwave must exist in a room before it is detected by our ears, our brains process this information and the perception is created of a sound tone at a certain frequency being present in the room.

3. Most humans cannot localize bass tones below about 80 Hz, meaning we cannot determine exactly where the sound is originating from.  But we are progressively better at localizing sound tones as their soundwave frequencies rise from about 80 Hz all the way to about 20,000 Hz. 

4.  The radiation pattern of deep bass soundwaves is 360 degrees meaning the soundwaves radiate out from the speaker in all directions.  The radiation pattern of midrange and treble soundwaves are much more directional meaning the soundwaves radiate outward from the speaker more in a straight line, like a beam of light. 

     You're on the right track thinking about all the angles of reflections in your room.  As you can see from the above fact #2, one of the reasons it's difficult to get good bass performance in domestic sized rooms is that the length of some deep bass tone soundwaves may exceed one or more of the dimensions of the room.  This means the long bass soundwaves must reflect off a room barrier (wall, floor or ceiling) before its entire length exists in the room, the ear can then detect it and the brain can process it as a bass tone sound at a certain frequency. 
      In smaller rooms, multiple long bass soundwaves reflecting off room boundaries, that are closer together, often meet or collide which causes bass at these spots in the room to sound exaggerated, attenuated or even absent.   Actually, you're fortunate again because your room is so large it can better accommodate multiple long bass soundwaves, which means fewer reflections off room boundaries that results in better bass response performance overall in your room.
     
Did you buy those lottery tickets yet? 
                   Tim

Ps. I’m not finished experimenting yet . I have cables still running cross country until i get a few days of listening in (100ft balanced mic cables )

.. music to movies to the news to radio on and on . Using a powered sub was the big thing . I honestly do not know how i would have achieved this result with out having adjustments . It sounds .. revolutionary. Thanks for your insight . It as it turns out is indeed mathematics as well as discovery. Over the last year tweaking  this system i have been imagining all the angles of reflection in this room (56x36x15) adding the subs almost seemed to erase the need for room treatment . As a matter of fact some of the adjustments on my c46 were then backed off a bit from their original settings for room correction !