Help me understand "the swarm" in the broader audiophile world

sounds_real_audio:
" The " swarm" is actually and old term that was used to convince music lovers who were not happy with the sound of their system, in particular  the midrange which was so lacking in most speakers. To deflect away from that they, the manufactures, focused on the bass, which as most of us know or should realize by now is so difficult to reproduce in a three way box without screwing up the overall sound. So now the swarm is a way of placating our type A male designer to have gut wrenching bass from a speaker. A conspiracy yes. Has it convinced anyone, yes it has. Does it make your system sound better, well perhaps, the bass may improve but you will still not have that rich and satisfying midrange which is where the music is."
   
 Hello sra,
     While we're awaiting your expected response to Duke's post requesting clarification, I just wanted to interject a few comments of my own, regarding your statements in your most recent post from 9/22, all based on my personal experiences utilizing a 4-sub DBA system (the AK Debra complete kit system) in combination with a pair of Magnepan 3.7i main speakers.  
     The word "swarm" itself has likely been around, probably 1st in some ancient semitic form, about as long as humans developed language and continued to absentmindedly stumble across hives. The 1st time I recall encountering the word swarm, in reference to subs, was in 2015 when I read the Absolute Sound review of the Audio Kinesis Swarm distributed bass array (DBA) system linked to below:
https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/
     
     In this context, Duke's recollection of selecting the word "Swarm" in 2006, to descriptively name his new four-piece distributed multi-sub system, seems to me to be the most sensible and logical origins of the term "swarm" in regards to sub usage, due to individuals subsequently and likely using the term "Swarm" to refer to the AK product specifically and the term"swarm" to refer to all four-piece distributed multi-sub systems in general.
     While I will take your word for it that it's very difficult to reproduce the bass in a three way box without screwing up the overall sound, even if a designer did manage to launch pristinely accurate bass, midrange and treble sound waves into a room from his ideal speaker creation, there's a high likelihood that these pristinely accurate sound waves will not be perceived as pristinely accurate bass, midrange and treble performance at the listening position due to two main factors:

1. The bass frequency sound waves are very long, have omnidirectional radiation patterns and behave very differently in any given room than the much shorter midrange and treble sound waves that have highly directional radiation patterns.
2. The bass, midrange and treble drivers are permanently attached in set positions in a typical three way box speaker cabinet and are incapable of being independently and separately positioned in the room, and in relation to the listening position, to optimize the perception of the complete audio spectrum along with good stereo imaging.

     I believe most individuals position their main speakers in the room, and in relation to the listening position, in order to optimize their perception of midrange and treble performance as well as stereo imaging performance. Due to factor#2 above, however, bass performance is typically unable to also be optimized and, as a result, individuals need to settle for compromized bass performance.
      In my opinion. the resolution of this non-optimization of bass performance at the listening position is the main justification for the intelligent positioning and configuration of one or more subs in the system and room. 
      I believe a single sub is capable of achieving good bass perception performance at a single designated listening position but the addition of more subs makes this achievement not only progressively easier, based on my knowledge and personal experience, but also progressively better in quality; better bass power, dynamics, speed, smoothness, detail and integration with the main speakers. 
     I perceive the bass performance of my current Audio Kinesis Debra 4-sub DBA system as being near state of the art.  It's definitely the best sub bass system I've used to date in my room and system, however, I don't claim it's the absolute best bass system because I'm fairly certain a custom 4-sub DBA system, consisting of larger and even higher quality subs (either self-amplified or passive driven by a separate high quality sub amp and active crossover network), would significantly outperform it.
      Of course, this type of custom 4-sub DBA would also be significantly more expensive than a $3,000 AK Swarm or Debra complete 4-sub DBA kit.  I've also never auditioned a properly positioned and configured multi-sub line bass array (LBA?) or a multi-open baffle sub line or distributed bass array system which could possibly outperform the AK DBAs.

Tim

Hello Erik,

     My wish for you is to audition and experience the Swarm.  Possibly Duke or James Romeyn could arrange it?  Or, you're welcome to stop by my house if you're near Indy.
     You could then state your objective, apropos thoughts on the Swarm.  Perhaps say your piece and move on?  I know I'd find it very interesting.

Tim

Hello m-db,

     Duke is just being modest. After Earl Geddes generously bestowed the gift of his amazing DBA concept upon him many years ago, what did Duke do?
     He took the initiative to develop a 4-sub complete kit finished product that very successfully took advantage of this DBA concept at a very reasonable and affordable price, the Swarm, and has been one of the major advocates for the concept ever since. The Absolute Sound magazine has also awarded the Swarm its prestigious Golden Ear Award multiple times over the years. I believe this definitely qualifies Duke as being a world class Bassist.
     In fact, I give complete credit to Duke, along with his associate James Romeyn, and Dr. Earl Geddes for my ability to enjoy near sota bass response performance in my room and A/V system on a daily basis.

Thank you very much guys,
Tim

northman:" My question is this: do in fact high-end stores embrace the concept of multiple, inexpensive subs? If not, cynicism aside, why not? Or why doesn't Vandersteen or JL or REL and so on design their own swarm? For those out here who love multiple subs, is it a niche thing? Is it a certain kind of sound that is appealing to certain ears? The true believers proselytize with such zeal that I find it intriguing and even convincing, and yet it's obviously a minority of listeners who do it, even those who have dedicated listening rooms. (I'm talking about the concept of four+ subs, mixed and matched, etc. I know plenty of folks who embrace two subs. And I may be wrong about all my assumptions here--really.)"

   Hello northman,

     I understand you're confusion, hesitancy and numerous good questions. When I initially learned of the 4-sub distributed bass array concept about 6 yrs ago through reading about the results of research on the use of multiple subs by Earl Geddes, Floyd Toole and Todd Welti, my thoughts were much the same as yours. 
     I actually learned about the effectiveness of the 4-sub DBA concept prior to discovering that Audio Kinesis offered two very similar, complete kit versions of the concept in their Swarm and Debra products for $2,800 at that time ( I think it's currently priced at slightly more). 
     In fact, I was initially planning on buying a pair of JL Audio F113 and a pair of F110 subs to try out this concept, for a total price of $15,000, before learning of the AK Swarm and Debra at considerably less.  Of course, saving so much money was my main incentive but AK's offer, of a free in-home 30 day trial period, made my decision to buy the Debra a real no-brainer bass bargain buy.
     When I first experienced the bass performance of my AK Debra 4-sub DBA in my system and room a little over 5 yrs ago, I felt like I was being let in on a big home audio secret and like I won the bass performance lotto.  I remember thinking: Why had it taken me so long to learn of this excellent bass solution concept and product? 
     Why wasn't this concept more widely discussed and utilized, especially by members of a high-end audio site like Audiogon?
      I know my very positive and early experiences listening to the 4-sub Debra DBA, which has not diminished in the last 5+ years, has caused me to be a very enthusiastic supporter of this concept and to often attempt to spread the word on its remarkable effectiveness on this forum ever since.  I don't apologize for this, realize Duke/audiokinesis remains the foremost authority on the swarm/DBA concept on this forum and  believe the increased discussions on this forum about this concept and multiple subs in general are beneficial to all.
    And you asked:" My question is this: do in fact high-end stores embrace the concept of multiple, inexpensive subs? If not, cynicism aside, why not? Or why doesn't Vandersteen or JL or REL and so on design their own swarm? For those out here who love multiple subs, is it a niche thing?
     I think many high-end stores do embrace the concept of multiple inexpensive subs, but I also think millercarbon was correct about money and profit margins and that dealers more likely embrace the concept of 
one expensive sub and really adore the concept of multiple expensive subs.  Hsw had a good point about REL and other sub companies starting to endorse the concept of multiple subs or stacks, too.  It's not  hard to figure out why, right?

     You also asked: "Other than room limitations, why would anyone buy a single JL or REL or Vandy sub when you could spend less and get .. the swarm? "
     If someone chooses to use a single sub, no matter its size, brand, quality or cost, rather than at least a pair of good quality subs, IMHO, they're most likely doing so due to a lack of knowledge and experience.  There's also the possibility that they're just blindly accepting some bad,  but obviously trusted, advice.  I think we'd probably learn more on why by listening to their answers to this question.
      I can state with certainty, based on personal knowledge and experience, that 2 subs will perform about twice as well as a single sub and that 4 subs will perform about twice as well as a pair of subs. I also believe, however, that you shouldn't take my word for anything I've stated on this post. I think we all generally learn the most and best through personal experience. 
     My shared Home Audio Deep Thought for the Day is that much personal audio knowledge gained is less about absolute truths and more about personal, subjective preferences.

Best of wishes to you grasshopper,
Tim

northman,

     I've been monitoring this thread and realized I had the urge to reply to almost every post, because I thought my comments would be beneficial to the posters, but have successfully been resisting these urges until now.  
     I've changed my mind, however, and now believe citing a previous post and adding my comments will not only be hopefully beneficial to the posters, but it will likely also help you in your quest to better "understand the swarm in the broader audiophile world".
     Before I begin, I just want you to know that I'm just a fellow Audiogon member and AK Debra complete DBA kit user who's a big advocate of the multiple sub concept in general and the 4-sub DBA concept in particular.  My comments are solely based on my personal knowledge and experience gained by researching multiple sub theories and concepts and trying them out in my own system and 23'x16' living, 2-ch music listening and home theater room.  Basically, I'm just an A/V hobbyist with no formal relevant schooling, training or A/V company affiliations that believes in full disclosure.
     Okay, enough of that, below I'll list the poster with their partial post quote and add my comments below each.  My current thinking is that this format could be beneficial to multiple thread participants but also that I could quickly get in over my head.  My intention is not to hijack this thread but to summarize, clarify and to assist the OP in better understanding the swarm concept:    

mapman:
 " Audio Kinesis (Duke) is also very knowledgeable and big on sound dispersion in general and I believe tries to enlarge that sweet spot with his designs. When that is the case ( a larger sweet listening area) the case for a more evenly distributed bass is also better."

     I believe this is generally true but wanted to add specifically how I implement the swarm since my goal was to broaden the bass sweet spot in my room for HT but to restrict  the midrange, treble and stereo image to a traditional sweet spot, meaning a pair of main speakers precisely positioned in relation to a single designated listening seat to optimize the midrange, treble and stereo sound stage illusion. 
     Here are some relevant facts to consider:
-Deep bass frequency tone sound waves are omnidirectional and exceptionally long (a 20 Hz very deep bass sound wave is 56' long).  
-Humans typically cannot localize (tell exactly where the sound is coming from) bass sound waves with frequencies below about 80 Hz and down to the audible limit of 20 Hz. 

-Midrange and treble frequency tone sound waves are highly directional and decrease in length proportionally as the tone frequency is increased (a 1,000 Hz midrange sound wave is 1.13' long and a 20,000 Hz very high treble sound wave is a fraction of an inch long).
- Humans are typically very adept at localizing midrange and treble sound waves beginning with frequencies above about 80 Hz and up to the audible limit of 20,000 Hz.
- Sound waves from 20 to 80 Hz are mono and perceived by us as mono  whether separate L +R channels exist or not. 
-Sound waves between 80 to 20,000 Hz are actually mono but perceived by us as stereo if separate L + R channels exist.
-All sound waves continue to bounce, or reflect, off of room boundaries (walls, ceiling and floor) until they run out of energy, are absorbed or are diffused.
-Humans require at least one full cycle sound wave to exist in the room to perceive any sound no matter the frequency.  Additionally, humans require multiple full cycle sound waves to exist in the room to perceive a change in pitch.  This only becomes an important factor on some very deep and very long bass frequency sound waves, which can potentially exceed the length of a room's dimension, and require a room boundary reflection for the full cycle length of the sound wave to exist in the room before being perceived, along with multiple sound waves existing to notice a change in pitch. 

    The above facts result in bass sound waves behaving, and being perceived by us, very differently than midrange and treble sound waves in any given room.  Because of this, I decided to take the approach of treating my system as two systems: a bass system and a midrange/treble/imaging system.  
     The bass is typically the hardest to get sounding right in most rooms.   My main point is that,  while the Debra  delivers near sota bass in mono throughout my entire room that serves as a solid foundation for all music I play on my system, I still position my main speakers precisely, in relation to a single designated listening seat, to optimize the midrange, treble and sound stage imaging.  My main speakers only have a rated bass extension down to 35 Hz and I run them full range with the Debra set at slightly less than 50% with the crossover frequency set at 40 Hz.  This results in a seamless integration of the bass with my main speakers.  
    Even though the Debra subs and my main speakers are all outputting the fundamental bass tones below 80 Hz in mono that cannot be localized, I still perceive a full range stereo sound stage because the harmonics or overtones of these fundamental tones, which reach frequencies above 80 Hz and can be localized, are being reproduced in stereo by the main speakers. 
     The secret sauce is then provided by our brains, which are  capable of associating the bass harmonics or overtones above 80 Hz with their related fundamental bass tones below 80 Hz, and create the perceptions of where specifically the fundamental tones are coming from.  This whole process is seamless and results in our being able to perceive the deep bass drums being located at the rear center of the sound stage image, for example, and the upright bass being located at the front left side of the sound stage image.

mitch2:
" Based on my experience going from one sub to two, as well as what I have read about the subject, I would like to try adding a third SW12 placed asymmetrically in the room.  If I were starting over, I would definitely try Duke’s Swarm Subwoofer System but as @erik_squires points out, you need to be willing to have four additional boxes in your room."

     Yes, I know with certainty that a good quality multiple sub bass system can be created using as few as a pair of good quality subs, provided they're properly positioned/configured and good bass performance is only desired at a single designated listening position and not throughout the entire room.
     Three subs have also been proven to be sufficient, in some rooms, to  form a DBA that is virtually as effective as a 4-sub DBA and is claimed to provide good bass performance throughout the entire room, not just a single designated room location.  I
      recall reading this in the Earl Geddes article linked below:
   https://mehlau.net/audio/multisub_geddes/
     Mitch2, you also may be interested in one or more of these good quality wireless subs that have received good reviews:

https://www.underwoodhifi.com/products/syzygy-acoustics

atmasphere:
" In a nutshell this is an education thing and nothing more.

Those that denigrate a distributed bass array are apparently simply ignorant of its advantages. Many dealers don't sell them, so their comments can be sidelined safely enough.

If your front speakers actually make bass, then what you do is add a pair of subs elsewhere in the room to break up the standing waves that often cause bass cancellation at the listening chair."

     I agree, the whole 4-sub DBA  concept is not overly complicated but does require some education, self provided at online sites or at least read this book I'm currently writing.  I think a good understanding of the underlying principles as well as proper setup and configuration procedures should be sufficient.

teo
" Actually Eric is correct in the idea that it does not fix the room. This swarm idea. It overwhelms the problems and buries it under noise, in an area where the human ear is least sensitive. Like Styx said, "you’re fooling yourself if you don’t believe it..."

First, Fix the room."

      I believe teo_audio and Eric are correct that the swarm does not fix the room.  As I understand the swarm concept, the 4 subs actually create an abundance of more bass room modes throughout the room and uses a well known psychoacoustic principle, mainly that our brains process an abundance of bass room modes present in a room by summing and averaging these room bass modes by frequency, which results in our brains creating perceptions that the bass is smoother, faster and more detailed.     
     During the first four years of using the 4-subb Debra system in my system, I utilized zero room correction software or hardware and the only room treatments existing in the entire room was wall to wall carpeting and a few live house plants. 
     This wasn't because I disagreed with, or wasn't aware of, the importance or effectiveness of quality room treatments in attaining optimum full frequency range audio performance.  I did, but just hadn't gotten around to having my room professionally analyzed and treated.
     I've since had a full professional room analysis done by GIK, purchased several thousand dollars of a variety of their suggested room treatment products and have had them all installed about a year ago. 
    GIK's recommendations included floor to ceiling bass traps in all 4 corners of my room, 3-5 additional bass trap panels scattered about and and about 20 midrange/treble frequency range absorbing and diffusing panels at strategic locations along the perimeter 4 room walls. 
     My main point is that I was initially leery about so much bass trapping treatments because the 4-sub Debra DBA had worked so exceptionally well, with virtually no treatments at all in my room, for the previous 4 years that I was concerned the abundance of bass trapping might negatively effect the Debra's excellent bass performance.  
     After reassurances from GIK and Duke that the added room treatments would not negatively effect the bass performance of the Debra DBA, I had all the GIK recommended room treatments installed in my room, including all of the bass traps.  I anyone is curious, you can view the room treatments on my system pics.
     Overall Duke and GIK were correct, the Debra's bass performance remained exceptionally good. I noticed significant improvements in my system's midrange, treble and imaging performance, mainly a substantially lower noise floor, improved detail and an even more realistic, deeper, wider and 3 dimensional sound stage imaging.
   So to those stating to fix the room first for Pete's Sake!, my experience is that it minimally effected my room and system's bass performance but dramatically positively effected most everything else.  Definitely worth the dough overall, IMHO, but obviously not required for very good 4-sub DBA performance.
     Okay, sorry for the War & Peace length of this post but I prefer my books be thorough.

I hope this tome helped someone,
    Tim

rixthetrick:
" mahgister Yeah, but did you have a swarm or an array of sub woofers?
If you did not, he was very specific in saying that he did, for many years, before applying room treatment. And it was in other areas he found the more significant performance increase with correct room treatment. The sub array had benefits all on it's own, would be my guess?"

Hello rixthetrick,
     You are correct, my AK Debra DBA performed exceptionally well in my room and system, very close to identically from my perspective, whether there were virtually zero professional room bass trap treatments or a complete GIK recommended quantity of them in my room.  I was actually expecting and hoping for at least some slight improvements but failed to notice any.
     I should note for clarity that there were no before and after room analysis measurements taken of my room to verify there were no improvements in bass performance resulting from the addition of the multiple GIK bass traps.  My comments are based only on my personal and subjective perceptions.

Enjoy,
Tim
     
    

Hello millercarbon,

      I bet our room bass qualities are very close.  I was so concerned the bass traps might detract from my DBA's bass quality, I was initially going to delete all the bass traps from GIK's plan for my room.  There was a lot of them and those GIK bass traps aren't cheap.  I know the DBA concept works perfectly with no bass traps at all and the absolute last thing I wanted to do is detract from its high quality bass in any way.  
      I believe anyone who's personally experienced the DBA's performance would feel the same way.  I've never really liked the idea of bass traps and these are the first I've ever used; they've never made much sense to me.  Your system produces bass and then the bass traps reduces it?  Huh?  It's always reminded me of running the AC with the windows open. 
      I know it's more complex than that, I probably just don't completely understand the acoustic dynamics at work and they could be the reason my system's performance from the midrange on up, along with sound stage imaging, has never sounded better.  I'm trusting some experts, GIK and Duke. they haven't steered me wrong yet and overall I'm very pleased with my GIK investment.

Later,
Tim

veerossi:
" I'm at a point where I have the gear I want and I have setup my speakers to the best of my ability. Room treatment is my next project. I know you went the GIK route. Sounds like all went well. What do you think about Acousticfields vs GIK vs others? What made you go GIK?"

Hello veerossi,
       I checked out the Acousticfields' website and their products seem to be of very high quality.  I think I considered them when I was looking for a room treatment vendor but thought they were a bit on the expensive side and I didn't know if the premium prices were justified.  I noticed they also offer a free room analysis just like GIK.
     I went with GIK mainly because a lot of members here seemed to like their performance, I liked their variety of treatments, especially the canvas art panels my wife really liked (which was important to me since it's her living room, too.) and they seemed like high quality treatments at reasonable prices.  I knew good quality treatments wouldn't be cheap but I wasn't looking to get fleeced, either. 
     Overall, I'm very pleased with the performance, fit and finish, customer service and total costs of the GIK products.  I'm not certain but I suspect the Acousticfields treatments are a step above the GIK in quality but also in price.  
     I'd suggest you take advantage of getting a free analysis from both companies, which will include a list of recommended products along with a total price quote, which will probably help with your decision.  This process also provides info on their customer service quality levels and differences along with the interesting and fun of comparing 2 complete and independent plans and strategies for your room.

Best wishes,
    Tim

brownsfan:
" For those of you using DBA combined with room treatments, did you find that the DBA reduced ringing substantially without room treatments, or should I expect my Swarm to primarily rectify nulls at the MLP and expect that the traps will be required to achieve good decay times?"

 noble100:  My negative experiences with decay times in my room and system actually occurred prior to even using a DBA and concerned the opposite of ringing, which was the truncation of decay times.   I've noticed this unnatural and premature cutoff of normal note decay times on both my former pair of Magnepan 2.7QR main speakers, driven by a stereo class D amp, and a pair of 12" subs with built-in class D amps. 
     I'm fairly certain the cause in both cases was the extremely high damping factors characteristic of class D amps in general, which are typically rated in the low thousands as opposed to usually being rated in the low hundreds for class AB amps. 
     The higher the damping factor, the more firmly an amp has control over the starting and stopping of drivers, in my former case the large 623 sq.in. planar-magnetic bass section in each of my former 2.7QR speakers and the 12" dynamic cone woofer drivers in each of my former self-amplified subs.
     Since replacing my dual self amplified subs 4 yrs ago, with the AK 4-sub Debra DBA powered by a 1K watt class AB amp, I've definitely noticed the bass note decay times are somewhat longer, more accurate and more natural with a total lack of truncation or ringing.   I've never experienced boominess or ringing with my DBA, either with zero bass room treatments prior or extensive bass room treatments currently. I seriously doubt you will experience any negative bass performance issues in your room, either.
     

brownsfan:
" I guess my plan would be to remove room treatments and optimize the bass response without room treatment, then add back the bass traps judiciously to further improve frequency response and ringing.  BTW, mains are down 3 dB at 27 Hz, but I have decent response down to 20Hz or so.  Is that a reasonable approach?"

noble100:  It's an approach, but I really don't believe it's necessary.  When I installed extensive room treatments in my room, I just made sure that none of the subs were firing directly into a wall or corner bass trap, ensuring each had at least a small section of bare wall to launch their bass sound waves into and not being in very close proximity to a bass trap.  This produced very good results in my room.
     Your mains already have fairly deep rated bass extension.  I think it would be more beneficial for you to pay close attention to the volume and crossover frequency control settings on your subs, as well as the slopes of the subs' crossover filters.
     Are you planning on using an AK Swarm or Debra complete kit DBA or creating a custom 4-sub DBA using self-amplified subs?   I can better tailor my advice knowing the details.

brownsfan:
" Finally, I've read about the crawl approach to optimal placement on the Audiokinesis site, but I'm thinking of using REW to supplement what I hear.  Anyone find REW useful in Swarm sub placement? "

noble100:  I sequentially and optimally positioned each of my AK Debra subs utilizing the crawl method.  I've never used REW or any room correction software/hardware, room analysis or mics but I do recognize their usefulness. 
     My best advice would be to first locate each sub using the crawl method and then utilize REW to further fine tune and verify optimum positioning.  Ideally, they'll result in the same position but, if not, it'll be at your discretion.

Best wishes,
   Tim
      

northman:
" And yet the discussion of multiple-sub array contains almost none of this fastidiousness. It's what academics would call a different discourse. It's by far the most casual approach to sound out here: mix and match inexpensive subs. What brand of subs? It doesn't really matter. What size? Also doesn't really matter. Should they be the same? Maybe, but it doesn't really matter. Where placed? It doesn't matter nearly as much as a single or pair. Connections, watts, power source? Doesn't really matter, relatively speaking.

My point is that, as an outsider to these technologies, the tenor of the discussion is completely different. It's not only asking audiophiles to consider a new approach to sound reproduction but asking them to consider a completely different way of thinking about, and talking about, the hobby."

  Hello northman,
     
     Good points.  There actually is a lot of technical, fastidious, scientific and interesting reading material available on-line, supporting the effectiveness of utilizing multiple subs and distributed bass arrays (DBAs) in home audio sized room environments, if you desire to learn more on the subject.  
     I suggest googling the writings of Dr. Earl Geddes, Dr. Floyd Toole, Todd Welti of Harman International and Duke LeJeune of Audio Kinesis for a good sampling.  You could also google topics such as "the use of multiple subs for home audio", "distributed bass arrays",  " how to obtain better bass performance" along with other topics you may be interested in.
     The DBA and multiple sub concepts are not really new but the use of subs in home audio has been traditionally shunned by many 'audio purists' in this hobby ever since I started began my journey in it about 45 yrs ago.
     I've never felt the need to restrict my personal audio knowledge, experiences and adventures to the confines of audio purist approved traditional lore, tropes and dogmas.  I've continued to attempt to maintain an open mind, listen well to others' experiences and tried to gain knowledge through personal experience whenever possible.
     I suggest you attempt to do the same since we all ultimately discover our own personal truths and preferences along the way.  I've even found my personal truths and preferences to change and evolve over time utilizing the simple, honest and unfettered approach of judging things on their merits and calling them as you hear or see them
     There's no denying there'll be a lot to see, learn, experience, reject and object along your personal audio/video  journey. Enjoy the journey  and I hope you don't mind if I refer to you as 'tiger', 'sparky' or 'young grasshopper' a few times along the way.

Later,
  Tim
  
     

dannad:
" There are two types of people, those who don't think low frequency bass is directional and accept that bass arrays must work, and those that think bass is directional and who put subs near their speakers invariably creating combing effects when there is bass leakage to higher frequencies either directly or through distortion that invariable is worse than any issues with directionality from a bass array."

     I just wanted to discuss dannard's comment above in a little more detail.
     I'm definitely in the camp that believes fundamental deep bass tones, under about 80 Hz, are not able to be localized without help from the naturally produced bass harmonics or overtones of these fundamental deep bass tones, that often extend well above 80 Hz and are able to be localized,  that are reproduced in stereo through the main speakers. 
     The key ingredient is our brain's amazingly sophisticated sound processing capabilities, developed and refined through the eons of evolution and natural selection to be currently finely honed in the vast majority of extant humans. One of the brain's extraordinary capabilities is the ability to associate the naturally produced bass harmonics or overtones of fundamental deep bass tones, that are above 80 Hz, reproduced in stereo through the main speakers and therefore localizable, with the fundamental deep bass tone itself, that are below 80 Hz, reproduced in mono through the sub(s) and therefore unlocalizable, and creates the perception of localizing the deep fundamental bass tone in space.
     This whole cerebral associative process, I believe, explains why , as dannard states:
" There are two types of people, those who don't think low frequency bass is directional and accept that bass arrays must work, and those that think bass is directional and who put subs near their speakers invariably creating combing effects when there is bass leakage to higher frequencies either directly or through distortion that invariable is worse than any issues with directionality from a bass array."

     I think there are two types of people as dannard states but I would describe them a bit differently:
1. Those that realize we all perceive deep bass tones below 80 Hz as not directional and therefore utilize bass arrays to obtain excellent bass performance.
2.  Those that believe deep bass tones below 80 Hz are directional, place a sub next to each main speaker to reproduce it and believe this configuration is responsible for their perceiving the deep bass below 80 Hz as stereo.  However, they're not realizing that their brain's ability to associate the mono fundamental deep bass tones, below 80 Hz that are actually being reproduced by their L+R  subs, with the stereo harmonics or overtones, above 80 Hz that are being reproduced by their main speakers, are the real reason they are perceiving the deep bass below 80 Hz as directional and in stereo.
     In my opinion, an understandable misunderstanding by group#2 above.  I don't think it's really a big deal, either, since both groups are ultimately perceiving the mono and nondirectional deep bass below 80 Hz as stereo.

Tim

unreceivedogma:
" A friend of mine who was the audio guy for the Untied Nations and the DJ for the Nuyorican Poets Cafe gave me a tip, which I have to try over the weekend:

Put the sub in the spot where your listening chair is. Then walk around the room. When you find the spot where the bass sounds tightest and deepest, that’s the spot to place the sub.

Assuming this theory works, I’m hoping that spot isn’t in front of the door to the room."

Hello unreceivedogma,

     Your friend's tip is a good one that I've used and recommended many times with very good success.  It's commonly referred to as the 'sub crawl' method and you're highly likely to find it to be very effective in your room as well.  
     If the result is actually in front of a door, placement immediately to the left or right side of the door will probably also result in very good bass perception at your listening seat.  This is technically a bit of a bass performance compromise but you can decide for yourself if it's a sufficiently subtle one to be acceptable. 

Tim

Hello paulburnett,

     I have no doubt a single sub can provide good bass response performance and integration with the main speakers, at a single designated listening seat, provided the single sub is precisely and optimally positioned in the room and in relation to the designated listening seat, the single sub is of sufficiently high quality, has the necessary three controls for level, crossover frequency and continuously variable phase and that all three controls are properly set. I know this with certainty because I’ve previously used a high quality single sub in my room and system with good results.
     My main intent of this post is to state with clarity for the benefit of readers of this thread, and not primarily for yourself, that based on my experience there are typically distinct advantages gained from utilizing 2 or more subs in most rooms.
     Two of the usual advantages perceived, beginning with the utilization of 2 subs, are more powerful and realistic bass power and bass dynamics. This is due to bass being cumulative in a room and doubling the subs not only increases the overall bass power and impact along with increased reserve power for realistic bass dynamics, it also improves the perceived quality and sense of ease of the bass since both subs are operating well below their limits and at low distortion. Other usual advantages perceived through the use of 2 or more subs are increased bass accuracy, smoothness, speed, detail and integration with the main speakers.
     I don’t completely understand why you didn’t perceive these usual bass performance advantages of utilizing 2 subs as opposed to a single sub in your room and system. However, I think it’s important to note that just because you were unable to perceive these typical performance advantages of utilizing multiple subs in your room and system, this has very little relevance in regards to whether others will be able to perceive these advantages in their rooms and systems. My belief is that many will perceive the advantages as obvious and significant. My suggestion is that those interested should try both a single and a pair of subs in their systems and decide for themselves.
     I do understand the more practical concerns of a smaller room, WAF and a lack of space for 2 or more subs. Based on my personal experience being able to accommodate 4 (1’x1’x28") subs in my 23’x16’ room, I no longer consider such concerns, that I also initially shared, as deal breakers. I think it’s more a matter of priorities, having the will for better bass performance and being sufficiently creative with room decor solutions.
     I can also state with certainty that it’s well worth the effort if you decide to give it a try and make it work.

Tim

erik_squires: " Thanks. I have no problem with the technology. Just the interactions and people who've gotten in my grill. As a result of that, you all go swarming all you want to, wherever you want to, for as long as you want to, and let me not."

Hello Erik,

     Rejecting swarming out of hand, without first-hand experiencing it, without maintaining an objective and open mind toward home audio solutions that are based on well understood acoustic and physics principles that have been validated and documented as being highly effective utilizing emprical scientific methods and research? And all because you perceive swarm users enthusiastically extolling its virtues as getting in your grill?
       Based on my recollection of reading your thoughtful, interesting and informative Audiogon threads and posts over many years, that I consistently perceived as commendably openminded  and objective, I consider your responses to swarming and its adherents to be surprisingly out of character. 
     Your reluctance to auditioning and experiencing the numerous benefits of a multi-sub swarm type distributed bass array system in your system and room, ultimately of course, will only be to your own detriment.  I'm just a bit surprised and disappointed that you're not more interested in giving the concept a try, evaluating the results honestly and objectively and sharing your thoughts and always interesting perspective with us all.  I'm certain you'd be pleasantly surprised.

Tim

Hello jdlynch,

     Since Duke hasn’t yet replied, I thought I’d give you my input and advice.
      I use the Audio Kinesis Debra 4-sub DBA in my system and room for about 40% 2-ch music listening and for about 60% 5.4 home theater surround sound audio. My main goal is for very high quality bass for both and the 4-sub DBA concept definitely provides this to near state of the art levels in my system and room.
You’ve stated your basement system, however, will be used about 90% for HT and your main goal for a bass system is more about providing powerful, room shaking and chest pounding bass.
     Duke, knowing the 4-sub DBA concept’s main attribute is its high quality bass, provided the good advice that a better solution for the higher amplitude bass you prefer would be to add 2 larger and more powerful subs to your system and create a custom 3-sub DBA system as he described, although the 2 additional subs do not have to be as large or powerful as your existing Submersive sub.  You would gain more bottom end power, impact and more powerful dynamics by adding 2 slightly smaller and less powerful subs while also gaining some DBA benefits such as increased bass detail, lower distortion and more seamless integration of the bass with your main speakers. 
     In giving his advice that you needn’t add 2 more subs as powerful or as large as your existing Seaton Submersive sub, I believe Duke was referencing Dr. Earl Geddes, the inventor of the 4-sub DBA concept, and his subsequent research and claims that 3 subs in a distributed array can be as effective as 4 subs in a distributed array in some rooms.
     I completely trust both of these men’s advice but I have no experience utilizing 3-sub DBAs, only 4-sub ones, and I’m therefore hesitant to offer advice on 3-sub DBA usage. I can tell you that I’ve adjusted the level of my 4 subs but I’ve never adjusted, or even felt the need to adjust, their delay settings. Volume, crossover frequency and phase are the only required settings on an AK Swarm or Debra 4-sub DBA, I seriously doubt it would be different on a custom 3-sub DBA.
     You may be interested in utilizing a $200 Mini DSP unit, however, which requires a single pair of L+R channel inputs and allows the connection and advanced control settings of up to 4 subs. I believe it would be very useful on custom 3 or 4 sub DBAs but unnecessary on AK Swarm and Debra 4-sub complete kit DBAs.

Best wishes,
Tim