[Duke]

The AudioKinesis Swarm subwoofer system made the Editor's Choice Awards for 2015, in this February's issue of The Absolute Sound, page 56.

From the entry:  "This system is based on the idea that the smoothest, most uniform bass response in a listening room is obtained by using multiple subwoofers in various (usually asymmetric) positions... This idea, says REG, is the answer to bass in rooms... The uniformity of response gives you a compelling impression of being immersed in the bass soundfield of the original venue in a way no single subwoofer can accomplish.  REG, review forthcoming."

"Review forthcoming."   Yes, there will be a full-length review of the Swarm, written by Robert E. Greene, in an upcoming issue of The Absolute Sound.   (Spoiler alert:  He likes it.)

[Russell Dawkins]

Congratulations. Robert Everist Greene is the most rational, thoughtful and thorough reviewer writing in North America, in my books.

The swarm is a significant concept and deserves attention, since bass reproduction is the biggest problem in most installations, to my ears - almost never right!

[JLM]

What Russell said!

[TomS]

Congrats and I'm glad a few people are starting to finally get it 

[ACHiPo]

Congrats!  Can't wait to get my room sorted and add Swarm.  Any plans to add wireless capability?

[a.wayne]

Congrats Duke ,

Can you give a brief description on how the Swarm subwoofer system differs from others currently being offered in  the market place ..


Regards

[jimdgoulding]

Congrats, Duke.  You may not have any real competition.  I heard your "Swarm' with a pair of Sound Lab stats and the low end was as transparent as the top end.

[gregfisk]

Congratulations Duke, I've been hearing about your swarms for several years now. It's great you are getting some attention for your efforts.

I'm curious, do all of the subs need to be the same, and if so why?

Thanks,

Greg

[neekomax]

That's great, man. Seems like there's not a lot of in-depth info out there about this interesting product.

One question I have... any ideas about using this system with my DSPeaker Anti-Mode Dual Core DAC/pre/proc? Seems like that might be a really powerful arrangement, but I'm unsure how the Dual Core would be connected and 'see' the array.

[Duke]

Congratulations. Robert Everist Greene is the most rational, thoughtful and thorough reviewer writing in North America, in my books.

The swarm is a significant concept and deserves attention, since bass reproduction is the biggest problem in most installations, to my ears - almost never right!

What Russell said!

Thank you Russell and JLM!  Robert Greene is indeed quite thorough.  Although TAS doesn't publish measurements, Robert runs them and runs them well.  He's an amazing person aside from audio... he turned down a job as head of the mathematics department at Tulane University (arguably an "Ivy League of the South" school) in order to take a position at UCLA, where (as of a few years ago) he was working on developing the multidimensional mathematics and theories for what comes after String Theory.   And he participates very actively in a Doberman Pinscher rescue organization... at any given time there are several Dobies living with him and Paige, just getting used to gentle interactions with humans.

Congrats and I'm glad a few people are starting to finally get it 

As you'll see when the full review comes out, Robert Greene totally gets it.   He even identified some advantages of the system that I hadn't really "gotten". 

Congrats!  Can't wait to get my room sorted and add Swarm.  Any plans to add wireless capability?

Alas no, sorry, no plans for a wireless Swarm. 

Congrats Duke ,

Can you give a brief description on how the Swarm subwoofer system differs from others currently being offered in  the market place ..

The problem the Swarm addresses is, audibly lumpy in-room bass response.  This is a fundamental acoustic characteristic of small rooms ("small" meaning "smaller than a recital hall" in this context).  This room-induced peak-and-dip pattern will ruin the response of any sub no matter how smooth it starts out, and the Swarm is an acoustic solution to this acoustic problem.

The Swarm consists of four small subs that are intended to be distributed around the room.  They are all driven by one central shelf-mounted amplifier.   The idea is, each individual sub inevitably generates a room-interaction oeak-and-dip pattern, just like any other sub does.  But these peak and dip patterns change dramatically with sub (or listener) location.  So with the Swarm, you have four dissimilar peak-and-dip patterns summing at any given listening location. 

The net result is far smoother than any one of these patterns could have been without EQ, and this smoothness holds up much better at different listening positions around the room than it would with one or two equalized subs.  And "smooth bass" = "fast bass", as it is the peaks in the response that make a subwoofer sound slow (the ear has poor time-domain resolution at low frequencies, so group delay is not nearly as bad as it looks "on paper").

Credit to Earl Geddes for the distributed multisub concept.

The single central amplifier is rated at one kilowatt and has a steep (24 dB per octave) lowpass filter, which is important because we don't want audible lower midrange energy leaking through the subs, especially those that are far away from the main speakers.   The amp also has a single band of parametric EQ, useful for addressing any remaining issue.   Since the Swarm results in much less spatial variation (that is, variation in frequency response from one location to another within the room), any remaining problem is likely to be global rather than local, and therefore a good candidate for correction via EQ.

One additional characteristic of the Swam modules is what I call "room gain compensation" tuning.  This is where the target curve for the subwoofer, before the room's effects, is approximately the inverse of typical room gain due to boundary reinforcement.   Room gain due to boundary reinforcement is typically 3 dB per octave, so the Swarm modules approximate a gentle 3 dB per octave rolloff trend from 100 Hz down to 20 Hz.    This is more gentle than is practical for an unequalized sealed box, so we use a vented box tuned to give this response.   It seems to work quite well.  I don't know why more subwoofer manufacturers don't do something like this... if a subwoofer starts out "flat", it will almost always end up with too much energy way down low after the room comes into play, and too much energy way down low = subjectively "slow" bass.

In the event that you get more boundary reinforcement in your room than our room gain compensation tuning was designed for, you can reverse the polarity of one if the subs (which may be beneficial anyway just from the standpoint of response smoothness), and/or you can plug the port on one (or more) of the subs, converting it into a low-Q sealed box.   So the system is unusually flexible. 

I'm not sure that description qualified as "brief"!

[lowtech]

For a guy who "gets it", he has some rather odd theories about how speakers sound best - when listened to outside.  Perhaps he not aware that a listening room is something that should help a speaker sound good rather than act as a determent.  Maybe he's not familiar with the concept.  Also seems that theory is at odds with your Swarm approach.  (Maybe his theory has changed since I stopped reading what he had to say a few years back.)

[Vapor Audio]

Good for you Duke, congrats!  Here's hoping the accolades bear you much fruit.

[JLM]

Question:  Who originated the swarm concept, Earl Geddes or Floyd E. Toole (while working for the Canadian Research Council)?

[Mike B.]

Somewhere up about Bob Crump is smiling

[Duke]

Congrats, Duke.  You may not have any real competition.  I heard your "Swarm' with a pair of Sound Lab stats and the low end was as transparent as the top end.

Thank you, Jim! 

The original idea for the Swarm was indeed to do a subwoofer system that would "keep up" with planars like Maggies and Quads.   
'
Over the years I had built a bunch of different types of subwoofers looking for one that would be subjectively fast enough to blend well with dipoles, but with the chest-thumping impact that dipoles lack.   I tried sealed boxes, equalized dipoles, EBS vented boxes, aperiodics, transmission lines, isobarics, and maybe others that I can't remember right now.  None of them had the"speed" I was looking for. 

Then one day, I think it was at CES 2006, I was taking Earl Geddes to the airport.  We stopped at the stoplight at Koval and East Harmon.  While sitting there, Earl said to me, "Duke, I've figured out how to get good bass in small rooms: Take a bunch of small subs and spread them around the room asymmetrically.  The sum of their individual dissimilar peak-and-dip patterns will be smooth."  Or words to that effect.  I instantly realized that was it, that was the answer to my quest for a dipole-friendly subwoofer technology.   So I said, "That's brilliant!  Can I license the idea from you?"  And he replied, "You can just use it."  And then the light changed and we continued on to the airport.  Yes, it was that fast, and a part of my world had changed forever.

So interesting Jim that you should mention dipoles, as they figured prominently in the quest that eventually resulted in the Swarm.

Congratulations Duke, I've been hearing about your swarms for several years now. It's great you are getting some attention for your efforts.

I'm curious, do all of the subs need to be the same, and if so why?

In my commercial Swarm system the subs are all the same, but that isn't necessary to get the benefit of a distributed multisub system.   In general, the in-room smoothness goes up as the number of independent (not clustered together) bass sources goes up.  So two subs are twice as smooth as one, and four subs are twice as smooth as two, and eight subs are a recipe for divorce.

Where I think the Swarm system offers an advantage over just combining a bunch of subs (similar or dissimilar) is:
 
1)  Room-gain-complementary tuning is probably especially beneficial when you have subs transitioning from adding in semi-random-phase in the modal region to in-phase down in the pressure zone;

2)  The ability to tailor system to room by reversing polarity on one of the subs and/or plugging ports;

3)  The crossover in the amp already has all the features you need; and

4)  The Swarm is fairly competitive in quantity of output, not just quality; in a system with dissimilar subs, the smallest one may become the limiting factor well before the others approach their limits.

That's great, man. Seems like there's not a lot of in-depth info out there about this interesting product.

One question I have... any ideas about using this system with my DSPeaker Anti-Mode Dual Core DAC/pre/proc? Seems like that might be a really powerful arrangement, but I'm unsure how the Dual Core would be connected and 'see' the array.

Something like the DSPeaker Anti-Mode unit would work great with the Swarm!  You see, the juggling act with EQ'ing a subwoofer is, when you fix a problem in one microphone location, you are usually making it worse somewhere else.  The Swarm's reduced spatial variance (see my previous post) means that there is far less frequency response variation from one location to another, so any problems big enough to need fixing are probably global rather than local.  So you won't be ruining the response elsewhere in the room as you fix it in one area. 

For a guy who "gets it", he has some rather odd theories about how speakers sound best - when listened to outside.  Perhaps he not aware that a listening room is something that should help a speaker sound good rather than act as a determent.  Maybe he's not familiar with the concept.  Also seems that theory is at odds with your Swarm approach.  (Maybe his theory has changed since I stopped reading what he had to say a few years back.)

You might want to read Robert's review when it comes out and see if he thinks the Swarm is at odds with his theories of sound reproduction. 

Good for you Duke, congrats!  Here's hoping the accolades bear you much fruit.

Thank you Ryan!  May your line of disgustingly affordable uberspeakers continue to keep your customers and your competitors up late at night, each for their own reasons!

Question:  Who originated the swarm concept, Earl Geddes or Floyd E. Toole (while working for the Canadian Research Council)?

That's a very good question, to which I do not know the answer. 

It is my understanding that Todd Welti, under the direction of Floyd Toole, undertook his study of symmetrical multisub systems at the same time that Earl Geddes was investigating asymmetrical multisub systems, with each completely unaware of the other's work.   

If Toole came up with the distributed multisub concept during his days at NRC in Canada, that may indeed predate Geddes' musings on the subject, but I'm not qualified to say. 

Somewhere up about Bob Crump is smiling

Did Bob use a multisub system?  If so, tell me about it!

[Mike B.]

"Did Bob use a multisub system?  If so, tell me about it!"

No, he just had a pair of entech woofers, but he spoke highly of you and your wife. Maybe I have the wrong Duke?

[Duke]

"Did Bob use a multisub system?  If so, tell me about it!"

No, he just had a pair of entech woofers, but he spoke highly of you and your wife. Maybe I have the wrong Duke?

I was one of Bob's dealers and a friend and fellow SoundLab fan, and used the JC1's that he helped design.  Lori had that "skinny hippie woman" thing going on that Bob had such an appreciation for.  She and my sister-in-law would dance on the sidelines in his room at CES.  I think I still have one of his little bottles of Snake Oil around here somewhere.  Bob Crump is missed by many. 

[Duke]

As a follow-up to an earlier post, Earl Geddes wrote his doctoral thesis on small room acoustics primarily in the modal region back in 1980.  I don't know at what point Earl came up with the idea of multiple subs asymmetrically distributed, but he's on record as saying that all of his thinking on low frequency reproduction in small rooms ("small" meaning "any sized room that you'd find in a home") goes back to that study. 

[Russell Dawkins]

I can't imagine better qualification than this for designing sub woofer systems for home use!!
No wonder it works so well.

[woodsyi]

Took a while to get noticed but finally you are getting the accolades you deserve.   

Seems like I have had the Swarm V2 for years.  Great with Soundlabs in an untreated room.