Do you use a Subwoofer when listening to stereo?

Does excluding sub from stereo make sense?


     No and here's exactly why in your case:
     Your B&W 804D3 speakers are very high quality, expensive and have a rated bass output extension down to the audible lower limit of 20 Hz.  However, it's highly unlikely that you're experiencing and enjoying bass response this deep at your listening position because the woofers, that are responsible for launching these very low frequency sound waves into your room are permanently affixed in their cabinet. This rarely discussed design flaw is true for any speaker, no matter its design type, that has a rated bass extension deeper than about 80 Hz. 
     This permanent affixation of bass transducers in a speaker means they're not capable of being independently positioned in your room, and in relation to your listening position (LP),  which is required to optimize the perceived bass response at your LP from 20 Hz up to about 80 Hz.  The truth is that, even if the bass transducers in a pair of speakers are launching pristeen deep bass sound waves into the room, it's highly unlikely these sound waves will reach the LP in the same pristeen condition.
      The explanations for this reality are detailed and best understood via physics and how humans perceive sound, especially below about 80 Hz.  The deeper a sound's frequency, the longer its corresponding full cycle sound wave and the higher a sound's frequency, the shorter its corresponding full cycle sound wave.  Think of sounds, and their corresponding sound waves, as a continuum from long and deep to short and high.  For example a 20 Hz full cycle sound wave is about 56' long and a 20,000 Hz full cycle sound wave is a fraction of an inch long. 
     It's important to know that the longer bass frequency sound waves have omnidirectional radiation patterns and the much shorter midrange and treble frequency sound waves have highly directional radiation patterns.  It's also important to realize that the longer, omnidirectional sound waves/tones, typically below about 80 Hz, are not localizable (individuals are able to determine their specific position in space) by humans and that the much shorter, highly directional sound waves/tones, typically from about 80 Hz up to 20,000 Hz, are highly localizable by humans, and progressively more easily as the frequency increases.
     In addition, there are some peculiarities in how we humans perceive sound and sound waves:

- We don't even perceive a sound as existing at all until our ears detect a full cycle sound wave at a specific frequency, our brains process the input from the ears and the brain creates the perception of the sound at that frequency. Anything less than a full cycle sound wave being detected, results in no sound being perceived. 
      This fact becomes especially important with bass perceptions in a finite room, since some full cycle deep bass sound waves may exceed the dimensions of the room.  This requires the sound wave to bounce or reflect at least once off of a room boundary (floor, ceiling or wall) before the full cycle bass sound wave exists in the room, is detected by our ears, processed by our brains and the perception of a bass tone at a specific frequency is created.

- Since we generally can't localize bass frequency sounds below about 80 Hz, we perceive all bass below about 80 Hz as mono, which means no true-stereo deep bass exists below about 80 Hz.
     I stated no "true-stereo deep bass" because we are capable of perceiving a form of stereo deep bass thanks to our amazing brains. Our brains are able to perceive a fundamental deep bass tone below 80Hz,  often reproduced by a sub and unlocalizable, as mono and perceive the fundamental deep bass tone's natural overtones or harmonics, which often extend beyond 80 Hz, are often reproduced by the main speakers and are localizable, in stereo. 
     Our amazing brains are then capable of associating the mono fundamental tone with the stereo overtones or harmonics and localize the deep bass tone.  The result is a form of stereo deep bass that I believe needs to be distinguished as something other than "true-stereo deep bass".  For you, this means you can incorporate a sub or subs in your system and you still perceive a stereo sound stage illusion that is equal to, or more likely better than, your current one.

     The next facet of acoustic sound physics it's useful to understand is that all sound waves, at all frequencies, launched into your room by either speaker or sub drivers will travel outward and continue to bounce or reflect off of room boundaries (floor, ceiling and floor) until they are absorbed or diffused/scattered by acoustic room treatments, run out of energy and naturally decay or they collide with another sound wave.   
     Whenever these sound waves collide with each other, it creates what's called a "room mode" at the specific room location of the collision.  These room modes/collisions happen all the time with midrange and treble frequency sound waves and, in an untreated room, are normally perceived as 'airiness' or 'liveness' qualities, which many individuals perceive as enjoyable. 
     However, these midrange and treble room modes/collisions also negatively affect tonal accuracy, stereo details and stereo imaging.  But these midrange and treble room modes affects can be reduced, mitigated and controlled to an extent through strategic deployment of sound wave absorbing and diffusing acoustic room panels/treatments. 
      These room modes/collisions happen often with bass frequency sound waves, too. In an untreated room, however, bass room modes are normally perceived as bass overemphasis (a bass peak),  bass underemphasis (a bass dip) or even a bass cancellation (a bass null).
      But these bass room modes affects are much more difficult to reduce, mitigate and control than midrange and treble room modes.  The required bass trap room treatments are larger, more expensive and can't always be aesthetically placed at the specific room position they're services are needed. 
     Okay, the preliminary topics have been covered on this tome, and it's finally time for me to tie this whole thesis together and get to my recommendations for your specific circumstances.
     Yes, I could have saved  a lot of my time and yours by just stating I agree with atmasphere's earlier suggestion of the Audio Kinesis Swarm 4-sub distributed bass array (DBA) system as an ideal solution but I thought it was more valuable with you having a good understanding for my reasoning for my suggestion.  Here's an Absolute Sound review of the AK Swarm system that gives a very good description of what to expect:

 https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

     I use the very similar AK Debra 4-sub DBA in my system/room and can state with certainty, if you have the available room space for four relatively small (1'x1'x2') subs in your room, that you'll be amazed by the near state of the art bass performance of this relatively affordable ($3,200) complete kit bass system.  It's attractive in your choice of woods, the subs would be positioned around the perimeter of your room and are easily concealable and the bass integrates seamlessly with virtually any pair of main speakers. 
     I also believe your very high quality main speakers deserve an equally high quality 4-sub DBA system.  I think you could probably come close to the Swarm's performance by utilizing a pair, of properly positioned and configured, high quality subs.  However, the very good bass would be restricted to a single designated listening position rather than throughout your entire room with the Swarm and the Swarm will likely cost a few thousand dollars less as well as being easier to set up and configure. 

Best wishes,
   Tim

Hello emergingsoul,

     Are you using an audio/video receiver to power your main speakers?  If so, yes you should set the front l+r speakers (your 804Ds) to "large" so they run fullrange.  Why do you have them set to "small"?
     You should also connect your asw 2000 sub to the "sub out" or "LFE" output on the back of your A/V receiver and optimally position your sub in your room, and in relation to your listening seat using the 'sub crawl method (google it). 
      Then adjust the volume, crossover frequency and phase controls on your sub until the bass sounds best to you.  The goal is to set the sub's volume and crossover frequency as low as possible while the bass still sounds very good to you.  
      Give this a try and report back with your impressions.

Later,
 Tim   

Hello hsw,

     Are you stating that you're using a pair of subs and you're hearing or measuring a bass mode between 60-70 Hz at your listening seat? If so, this just means that at least one of your subs are positioned poorly in your room and in relation to your listening position (LP).  Apparently, your LP is in close proximity, or smack dab in the middle of, a bass room mode which is heard as a bass peak, dip or null.
     When utilizing 1 or 2 subs in a room, and the 'sub crawl' method is used to properly position them in the room and in relation to the LP, one of its major advantages is that this method ensures that there are no bass room modes in close proximity to the LP.
      I suggest you google the 'sub crawl method', utilize it to sequentially locate both of your subs.  Then adjust the volume and crossover frequency controls on both to the lowest settings you can while still maintaining bass performance that sounds good to you (it's solid, powerful, smooth, fast, detailed, dynamic, tonally accurate and it sounds natural).   Only once these steps have been completed,  would I recommend measuring your room to verify results.
     One or two subs in a room, provided they are optimally positioned in the room and in relation to the LP utilizing the sub crawl method, are capable of providing good bass performance, that is bass mode free, at a single designated listening position.  If you walk around the room away from the LP, however, you'll notice there are still numerous bass modes at specific spots in the room, heard as bass peaks, dips and nulls. 
    Utilizing 4 subs in a room in a distributed bass array (DBA) configuration in a room are also capable of providing good bass performance that is bass mode free.  But its main advantage is that it'll do so throughout the entire room and not just at a single LP. 
     If you walk around the room away from the LP after a 4-sub DBA  is installed, such as an Audio Kinesis Swarm or Debra DBA system, you'll notice there are no bass modes of any type perceived at any specific spots throughout the entire room.  

Later,
 Tim
    
    

emergingsoul:
" noble100
thanks so much. awesome

so maybe setting up the speaker settings to large (rather than small) makes more sense so that it completely opens up the main speakers. Why bother restricting bass on mains, and then set the subwoofer separately via settings on back of cabinet..

The sub array setup may have merit in a larger room. My room is 12 x 16 with 7 1/2 ceilings. The extremely large asw 2000 from b&w with 12 inch driver set lower would seem more than adequate. I do need acoustic panels."

Hello emergingsoul,

     The choice of whether to operate one's main  L+R speakers full range. or restrict their low frequency output, should be based on the main speaker's efficiency, their rated bass extension, the specs of the amp driving them, whether a sub or subs are going to be employed and personal preferences.  
    In your case, for example, I believe your speakers are sufficiently efficient, have a sufficiently deep rated bass extension, your amp has sufficient power and current capacity and your going to employ at least 1 sub.  This means everything's a go for operating your main speakers full range and it just will depend on your personal preference. 
     I suggest you change your main speakers setting to large (rather than small), optimally position your sub in your room using the sub crawl method and setting your sub's volume and crossover frequency controls as low as possible with the bass still sounding very good to you.
      Then it's up to you concerning which system set up and configuration overall system sound quality you prefer.

Best wishes,
  Tim

Hello emerging soul,

     I’m thinking you’re probably getting a bit overwhelmed and confused right about now, due to all the varied, pro and con advice you’ve been receiving on this thread about subs.
     It’s not unusual for some groups of audio enthusiasts to be against the use of subs. One group considers themselves ’traditionalists’ or ’purists’ that accept, without challenge and regardless of evidence to the contrary, the long standing audio hobby trope that subs shouldn’t be needed or used and just continue to parrot this outdated and misguided belief.
     Other overlapping anti-sub groups, that may or may not consider themselves audio traditionalists or purists, consists of those who have never experienced the sound quality of a good system with 1 or more subs optimally incorporated and those that have attempted to integrate 1 or more subs into their own system but perceived the results as negative for some reason. It’s important to note that individuals in this latter group could have perceived poor results from their attempted sub incorporations due to not following reliable and proven methods of incorporating 1 or more subs into a room and system.
     My main point is that it’s fairly common for individuals, even among otherwise knowledgeable and experienced Audiogon members, to be unaware of these reliable and proven methods of incorporating 1 or more subs into virtually any room and system. I believe this lack of knowledge and experience explains the opinion of some that incorporating 1 or more subs is difficult or not possible.
     My intention is to urge you not to become discouraged by the sub naysayers, they just don’t know what they don’t know. I can assure you that, if you follow my advice, you’ll be able to very successfully incorporate 1 or more subs into your room and system. Rest assured, there are very effective, and fairly simple, methods of reliably and effectively incorporating 1 or more subs into virtually any room and system, regardless of the main speakers utilized.
     I’m willing and able to guide you through the process if you’d like. The only stipulation is that 1-2 subs are required to provide good bass at a single designated listening position and a minimum of 3-4 subs are required to provide good bass performance throughout your entire room.  The reasons for this are a bit complex but I can explain them to you if you'd like.

Later,
Tim

wolf_garcia:" Using subs while running main speakers as they were designed at full range, at least the full range they're capable of, works fine. My 2 RELs simply enhance the sound of my mains and add the necessary low bass, and are easily dialed in without the unnecessary addition of an extra crossover...time for low bass is essentially irrelevant and correct phase is easily dealt with...note that if you're in a small club near the musicians (remember those?) with a band across a stage, you hear all the instruments with timing delays...drummer 10 feet away from the piano, guitar player on the side with plexiglass barriers...whatever...and the result of all that can be great sounding music. Don't be warned off by self appointed experts, except me of course."

+1 wolf_garcia  Well said and I agree with everything you stated.  Humans are not nearly as sensitive to the arrival time of bass frequency sound waves as we are to the time alignment of midrange and treble frequencies. 
     Bass sound waves are extremely long, spread out in all directions from the driver, whether the woofer is in a main speaker or a sub, and they continue to reflect off room boundaries (walls, ceiling and floor) until they're either absorbed or run out of energy. 
     In fact, we don't even hear or perceive any bass sound at all until the very long complete full cycle bass sound wave is detected by our ears/brain.  If we detect anything other than a complete full cycle sound wave, we hear or perceive any sound at all.   If the room is not very large, this means the very long full cycle bass sound wave must reflect off of 1 or more room boundaries before it is even recognized by our ears/brain as such and a perception of sound generated by our brain. 
     The truth is, much of the deep bass sound we hear in a room is perceived as a result of reflected sound waves.  Given these physical realities in most normal sized rooms, it's obviously not possible to time align  over the entire audible frequency range.
     It's virtually impossible to ensure  that the long and omnidirectional bass sound waves arrive at the designated listening position at the same time that the much shorter and highly directional midrange and treble sound waves arrive,  Fortunately,  it's not relevant since humans don't require time alignment for accurate sound perception.

Tim

" Nobil100, no it is not fine to run satellites full range while adding subs for three reasons. First is you miss the opportunity to lower distortion and increase head room significantly in the satellites."

Hello mijostyn,

     I googled emergingsoul’s stated main speakers, B&W 804 D3, before I made any comments on his thread and these are what came up:

https://www.bowerswilkins.com/home-audio/804-d3

     These are the floor standing, full range satellites my comments were based on and they have a rated bass extension down to 24 Hz. Just like any pair of floorstanding speakers, of course, I realize it’s highly unlikely that their rated bass extension will be heard or perceived at the designated listening position without the utilization of at least 1 properly positioned and configured sub in the room.
     Apparently, you’re under the impression he has stand mounted bookshelf type satellites with limited low frequency output. If this were the case, then I’d agree with most of what you stated. But I definitely don’t agree with your statement:

" Unless you are using digital bass management matching phase and time are difficult, usually by trial and error moving the speakers and perhaps by using a phase control on the sub."

     Your statement is incorrect because bass sound waves are extremely long, spread out in all directions from the driver, whether the woofer is in a main speaker or a sub, and they continue to reflect off room boundaries (walls, ceiling and floor) until they’re either absorbed or run out of energy.
     In fact, we don’t even hear or perceive any bass sound at all until the very long complete full cycle bass sound wave is detected by our ears/brain. If we detect anything other than a complete full cycle sound wave, we hear or perceive any sound at all. If the room is not very large, this means the very long full cycle bass sound wave must reflect off of 1 or more room boundaries before it is even recognized by our ears/brain as such and a perception of sound generated by our brain.
     The truth is, much of the deep bass sound we hear in a room is typically perceived as a result of reflected, and not direct, sound waves. Given these physical realities in most normal sized rooms, it’s obviously not possible to time align over the entire audible frequency range.
     It’s virtually impossible to ensure that the long and omnidirectional bass sound waves arrive at the designated listening position at the same time that the much shorter and highly directional midrange and treble sound waves arrive, Fortunately, it’s not relevant since humans don’t require time alignment for accurate sound perception.
     In regards to matching phase, your statement is more accurate. However, it’s also true that inverting the phase on a single sub, in a room with multiple subs, can improve perceived bass performance.

Tim

cakyol:"It is all a personal taste. Some do like it, some do not. I do."

Hello cakyol,

     Overall, I agree with your statement about supplementing the bass of the main speakers in a stereo system and room with subs. For readers of this thread who are considering adding one or more subs to their room or just want to learn more about how to do it well, however, I think it’d be beneficial to elaborate a bit.
     In my opinion, it’s very unfortunate and misleading when those opposed to the use of subs falsely portray the effects of subs as ’boom, boom, boom, one note bass’, ’subs are only good for ht’ and ’subs just draw attention to themselves and are too difficult to integrate well with the main speakers’.
     From my perspective and experience, these types of statements are just very obvious and reliable indicators that the commenter has failed to implement 1 or more subs in their own system, are simply describing the results of their personal unsuccessful sub integration attempts,, are unaware of how to do it well and, therefore, have never experienced the high quality bass performance and seamless integration when 1 or more subs are incorporated in a room and system skillfully.
     My experience is that good bass performance can be achieved, at a single designated listening position, in most rooms utilizing 1 or 2 subs provided the subs are optimally positioned in the room, and in relation to the LP, through the use of the sub crawl, automated room correction or in room electronic measurements. My definition of ’good bass performance’ is bass that is solid, powerful, detailed, tonally accurate and natural along with being well integrated with the main speakers.
     I believe in the axiom, however, that 2 subs perform about twice as well as 1 sub and 4 subs perform about twice as well as 2 subs. The main reason for my belief in this axiom is personal experience with its veracity in my own system and room. I find it amusing that some sub naysayers attempt to discredit this axiom by suggesting the use of 8 or 16 subs, wouldn’t that provide even better bass performance?
     Well, the answer is a definitive yes, in-room bass performance is improved in direct relation to the number of subs being utilized in a given room, according to scientific experiments and research conducted by acoustic experts Dr. Earl Geddes, Dr. Floyd Toole and Todd Welti of Harman International.
     Importantly, this independently verified sub research also discovered that in-room bass performance improved significantly with each sub added up to the threshold of 4 subs and that each sub added beyond 4 only improved bass performance to a smaller and more marginal extent. This research result, along with the fact that there’s a practical limit to the number of subs that individuals will accept in their rooms, are the rationale for the Audio Kinesis Swarm and Debra complete kit DBA systems, along with most custom DBA concept sub systems, typically utilizing 4 subs or less.
     Based on my experience, there are 3 main benefits of adding a 2nd sub to a single sub system: 1. The overall system bass power and bass dynamics capacities are increased, since bass is cumulative in a room and the number of subs has been doubled, which results in the bass being more capable of faithfully reproducing whatever the bass demands of the source material may be. 2. Bass distortion is reduced, since each sub is operating at a reduced level and well within its limits. 3. The other general benefits of utilizing multiple subs in a room also begin to take effect and become noticeable with the use of 2 subs. Qualities such as increased bass smoothness, speed, detail, sense of ease, improved stereo sound stage illusion and better integration with the main speakers.
     When I began using 4 subs in my room, I experienced further enhancements to all the 2 sub benefits mentioned earlier along with an immersive quality to the bass and an absolutely seamless integration of the improved bass with my main speakers.

Tim

Hello emergingsoul.
Here are some answers to your statements and questions from your last post on this thread:

emergingsoul:" I don’t get multiple subs.
waves of low frequencies are very large so the spread all over quite well. A nice 12 inch drive does not seem to need any help in a room that’s say 15x20. Smaller subs I guess might be spotty and maybe more than one might make sense."

noble100: Low frequency sound waves are not actually very large but they are very long. A deep bass 20 Hz sound wave is about 56’ long.
     It’s also not true that the 12" woofer drivers in your pair of B&W floorstanding tower speakers don’t need any help in your 15’x20’ room. You are correct, however, that the bass sound waves launched by the woofers in your speakers do radiate outward in all directions. Once your pair of tower speakers launch their bass sound waves into the room in an omnidirectional pattern, however, the physical dynamics involved do become a bit more complex.
     Once these long bass sound waves are launched into your room, they proceed in an outward direction until they encounter a room boundary (floor, ceiling or wall) and are reflected in a different direction. These reflected bass sound waves then proceed in a redirected path until they encounter another room boundary, run out of energy and decay or collide with another bass sound wave.
     Whenever these reflected bass sound waves collide into each other, they create what is called a ’room bass mode’ at the specific room point of the sound waves collision. When these bass room modes are detected by our ears, they are processed by our brains and a perception is created of hearing one of three possibilities, depending on the angle and direction of the collision, at this specific room location: a ’bass peak’ that’s perceived as a bass overemphasis, a ’bass dip’ that’s perceived as a bass attenuation or a ’bass null’ that’s perceived as an absence of bass.
     At this point, it’s necessary to introduce another factor into my explanation of your room and system bass dynamics realities, the use of fixed position bass sources. Since you probably position your main speakers in your room and in relation to your designated listening position like most of us do, to optimize the midrange, treble and stereo imaging performance, this creates an impediment to optimizing bass performance at the LP. This is because there are only 2 bass sources (your pair of B&W floorstanding tower speakers) launching bass sound waves into your room and they’re permanently affixed in their floorstanding tower speaker cabinets.
     This means these 2 bass sources are unable to be independently positioned in your room, and in relation to your listening position, to optimize bass performance at your LP. The main issue with having fixed position bass sources in your room, such as your pair of floorstanding tower speakers, is that you’re unable to ensure there are no room bass modes existing at your designated listening position. This means you could have a significant bass room mode at your LP, which you would perceive as a significant bass peak, dip or null, and the only remedy is to independently position and configure 1 or more bass sources/subs in your room.
     It’s also important to understand the well understood psychoacoustic principles that come into effect when multiple bass sources/subs are utilized in a room. For example, the 3-4 sub distributed bass array (DBA) concept that provides near state of the art bass performance to virtually any domestic sized room and seamlessly integrates with any pair and type of main speakers, creates the perception of being in a larger space even in small rooms and is the basic concept behind the award winning Audio Kinesis Swarm 4-sub DBA complete kit system linked to here:

https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

     This 3-4 sub DBA concept, whether a custom system or an AK complete kit system, is based on a well understood, but somewhat counter intuitive, psychoacoustic principle that relies on increasing, rather than decreasing, the number of bass modes existing in the room. Adding bass sources/subs to a room increases the number of bass sound waves launched into the room, which in turn and reliably increases the number of bass sound wave collisions in the room which results in an increase in the number of bass modes present in the room.
     Fortunately, this is where our brains and psychoacoustics take over, make sense of it all and ’do the magic that they do’. Psycho-acousticians (yes, that’s what they’re actually referred to as.) have discovered that when our brains are confronted with a sound environment containing an excess of bass room modes, they process and make sense of this chaos by summing and averaging these numerous bass modes by frequency. As a result, our brains create a perception of the bass in the room as being powerful, smooth, fast, detailed, tonally accurate, dynamic and seamlessly integrated with the main speakers.
     I realize this all sounds too good to be true but I can attest to the fact that my AK Debra 4-sub complete kit DBA definitely provides these spectacular results in my combo 2-ch music and 5.4 surround sound home theater system and 23’16’ room for the past 5+ years.
     Attempting to spread the word on the DBA’s incredible effectiveness has, admittedly, been somewhat frustrating since I understand all my words may convince noone but, even a brief audition of a properly positioned and configured DBA, would likely convince virtually anyone.
     If you feel curious and adventuress, emergingsoul, I suggest you could begin to experiment, and experience the benefits of the DBA concept, by creating a basic 3-sub DBA in your room. You could consider and utilize your existing pair of main speakers as 2 fixed position subs, obtain a good quality new or used sub as sub #3 and optimally position it in your room using the ’sub crawl method’. You can google the term for details.

emergingsoul: " Further, does it really matter where the sub is positioned? If I blindfolded someone and said find the sub, could you find it?"

noble100: Most humans cannot localize (determine specifically where a sound is coming from) sound tones that have frequencies below about 80 Hz. So, as long as the sub’s low frequency crossover filter control is set at about 80 Hz or lower, the sub should be able to be positioned anywhere in your room.

I hope this thesis helped you,
Tim

atmasphere:" I get similar impact on my speakers at home, which are flat to 20Hz. The problem I run into is a standing wave that causes a loss of bass on certain notes at the listening chair- they are certainly there in other places in the room! That's why I got a pair of the Swarm subs, just to break up the standing waves. The speakers can shake the organs in your chest and the cuffs of your pants and they don't sound boomy. "

Hello atmasphere,

     My main floorstanding speakers are 6'x2' planar-magnetic panels that only have a rated bass extension down to 35 Hz and also lack the ability to reproduce powerful bass dynamics.  I believe the ability of a home audio system to powerfully and accurately reproduce the bottom 2 octaves of bass and bass dynamics, like that heard and felt when listening to live music, are what distinguishes a good hi-fi from a high quality hi-end system.    These are the tactile and palpable qualities, along with a tonally accurate and detailed midrange and treble presentation with powerful dynamics and three dimensional stereo imaging, that are able to create the very realistic sound stage illusions in our rooms.
       The AK Debra 4-sub DBA system has proven to be an ideal bass supplement in my system and room, not only providing my system with the lacking deep and powerful bass and bass dynamics in the lowest 2 octaves but also doing so while seamlessly integrating with my main speakers.  And yes, it is capable of shaking the organs in my chest and probably the cuffs in my pants, if I ever become so dorky that I actually have cuffs in my pants. 

mijostyn:" If you but the subs against the front wall there is no early reflection point off that wall so only the floor and ceiling are comb filtering. On top of this you get all the benefits of a swarm system. Moving to the swarm as is normally used with say an 80 Hz crossover, to function as one driver the the subs would have to be within 8 feet of each other which is actually doable in most rooms. If you kept them all within 8 feet from one to the next what would happen? Tim, why don't you do that experiment and let us know what happens. I have no idea."
     
Hello mijostyn,

     From what I've read about bass line arrays and your description of yours, I have little doubt that it performs as well as you state it does, maybe even better than my 4-sub DBA in the right room.  I would love to try one or at least hear one in action sometime.  However, I think I'd probably need a more agreeable room and wife to do so. 
     I'd also be concerned about the effect it might have on the sound from my main speakers positioned in front of this solid bass wave and bass cancellation effects when this solid wave reflected back off my room's rear wall.

Later,
 Tim