Searching for matching(?) Subwoofer solution


Hi folks,

I have a relatively new setup in my home office (12' x 14' with hardwood floor) and am seeking recommendations for a subwoofer solution.

Speakers: Ologe 5
Preamp:    Bryston P26 
Amp:         Forte 1A
Budget:     Flexible but just want something to provide a good match for the above components.
Music:       Mostly Classical and Jazz.  Some rock, some fusion.
Source:     Well, that's something else I am seeking advice on too and will post under the appropriate discussion topic

Problem is none of the local Hi Fi shops here in the Boston area have any experience with, let alone heard of Ologe speakers.  Couldn't get any recommendations there.

Has anyone owned or at least listened to these speakers? Or any of the other Ologe speakers?
The Ologe site (http://www.ologe-acoustic.com/) features a subwoofer called Ologe 20 at USD $8550.  
Just wanted to look into alternatives before dropping over 8 grand on the Ologe 20.
 I am open to but don't know much about subwoofer swarms.

I am not looking for anything overkill.  Just a subwoofer solution to nicely complement my somewhat modest home office system.

Thanks,
H
hleeid

Showing 35 responses by noble100

Hello hleeid,

     Everything millercarbon stated is true, a 4-sub distributed bass array is the best solution.  However, in a home office environment in which I'm assuming you'll be listening primarily from your desk chair, I think a pair of SVS-SB1000 subs, currently on sale for 1/2 price at $499 each and $950 for a pair, will provide very good bass performance, if properly positioned in your room, that will also integrate or blend with any pair of main speakers used.  There's absolutely no need to use the same brand subs as your main speakers and you're going to save at least $7,000.
     Here's a link to the SVS website and the SB1000 subs:
www.svsound.com/products/sb-1000?gclid=Cj0KCQjws7TqBRDgARIsAAHLHP6Vm0QPz9ILXcyN2AvpfJDm-f5eEB6ODR4u6...
     These are very good quality subs at a great price. They also have all the necessary controls of volume, crossover frequency and continuously variable phase control that will enable you to seamlessly blend the added bass with your main speakers.
     If you decide to buy a pair of these subs, or any other pair of subs, I'm willing to describe the method to position and configure them for optimum results.  I have no financial interests in SVS, I'm just retired and willing to assist.

Tim 
Hello Hans,

    I bought my 4-sub DBA system, the Audio Kinesis Swarm, for $2,800.  Here's a link to a review of that that system: 

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

     Millercarbon built his own custom 4-sub DBA system, a copy of the Swarm but with upgraded woofer drivers, for about the same price.  I'll let him describe this option if you're interested.
     You could also build your own custom 4-sub DBA system by purchasing 2 pairs of the SVS SB1000 subs for about $1,900.  This option, however, is the most difficult to properly configure because the three important settings, volume, crossover frequency and phase, need to be set on each of the 4 subs.  With my Swarm and millercarbon's custom Swarm clone, all three controls only need to be set just once on the sub amp/controller for all four subs as a group.

     Any of these three 4-sub DBA system options will result in excellent perceived bass throughout your entire office.  The 2-sub option I mentioned will provide a more limited area of very good perceived bass centered on your desk chair position.  From your desk chair, all options will provide very good bass response that will sound seamlessly integrated or blended with your main speakers.

Tim
Hello mcreyn,

     I view this thread as a collaborative effort to try and assist Hans in arriving at the optimum solution for good bass performance in his home office in combination with his pair of Ologe main speakers, not a competition.
     If you reread my posts, you’ll realize I mention a 4-sub DBA system as the optimum solution but not the only solution. I agree that a two sub solution may be a very good solution in his particular case. If Hans decides on a two sub solution, I think it’s still important he realizes there’s a wide range of suitable subs he could use of varying qualities and prices. It’s also important that he makes sure the subs have the required volume, crossover frequency and phase controls and that they’re optimally set. We can let him know how to best set these once he makes his decision on the subs and configuration to use..

Tim
Hans,

     There are a large number of very good quality subs currently on the market that would work well for you in your home office and with your Ologe main speakers.  The choice is yours and I'd only caution you to make sure the subs you choose have the following features:

1.  Line level and speaker level inputs.  The line level inputs allow for connecting the outputs on a preamp to the sub via rca cables.  The speaker level inputs allow for connecting the speaker outputs on a power amp to the sub via speaker wires. 
2. Controls for setting Volume, Crossover Frequency and Phase.  The proper setting of these controls are required for seamlessly integrating or blending the bass coming from the subs with the midrange and treble coming from the main speakers.

     In general for in-room bass, two subs will sound twice as good as one, four subs will sound twice as good as two and eight subs are valid grounds for divorce.    
     Once two or more subs are deployed in any given room, the very important and beneficial psychoacoustic principles come into play.  Psychoacoustics refers to how our brains process sound and perceptions of sounds are formed.  I'll post again soon to describe the primary role psychoacoustic principles play in explaining why the 4-sub DBA concept is able to provide such exceptionally good bass performance in virtually any given room.


Hello Hans,
     I thought you might like a description of what bass performance to expect in your office by adding between one and four subs.  This is all based on my personal experience in my 23' x 16' x 8' room and my system but I believe these results are attainable in virtually any room, system and with any pair of main speakers utilized.
      I've discovered that one sub is able to provide good bass performance at a single designated listening seat if located properly utilizing the 'crawl' method but you may find it difficult, depending on the main speakers utilized, to configure it so that the bass seamlessly blends with the sound performance of your main speakers' reproducing the mid-bass or midrange on up to the treble. The bass may sound as if it's lagging behind and/or disconnected from your main speakers, especially on fast, smooth and detailed speakers such as electrostatic and planar-magnetic panels. I don't know much about your Olege speakers so I'm not certain if they're fast, smooth and detailed enough to cause integrating seamlessly with a single sub an issue.
    I understand most individuals would prefer to buy a single top-notch sub and be done with it but, unfortunately, the truth is that attaining good in-room bass response is not that simple no matter the price or quality of the single sub. The reason this is true really has more to do with the quantity of subs in a given room and how they're positioned, than the quality of the subs utilized. Better quality of subs never degrades from good bass performance, it's just not as important as most would assume. I'll try to explain why.
      Two properly positioned and configured subs in a given room typically provides bass response at a designated listening seat that's approximately twice the quality level of utilizing a single sub. Two subs provide increased bass output capacity and impact as well as increased bass dynamics due to the sharing of total bass requirements between two subs operating well within their limits and stress free with ample power reserves for sudden bass output dynamic demands.
    Psychoacoustic principles also begin to be applied beginning with the use of two subs in any given room that results in the bass being perceived as smoother, more detailed and better integrated with the main speakers.  
    To understand how this psychoacoustic process works, it's important to understand how bass soundwaves behave in a room with a single sub. Soundwaves increase in length as the frequency decreases and deep bass tone soundwaves are very long. A full cycle soundwave of a 20 Hz deep bass tone is 56' long, a 30 Hz is 36', a 40 Hz is 28' and a 50 Hz is 23'. For reference, a full cycle soundwave of a 20,000 Hz high treble tone is a fraction of an inch long. This mainly explains why humans are easily able to determine the originating source location (localization) of the shorter soundwave and higher frequency tones above about 80 Hz and are unable to do so on the longer soundwave and lower frequency tones below about 80 Hz.
    It's also important to know three facts:
1. Our brains can't even process the presence of a deep bass tone until the full cycle soundwave exists in the room and our ears have inputted this information into the brain.
2. Our brains require the input of at least three full cycle bass tone soundwaves before we're able to recognize a change in bass volume and pitch.
3. Our brains cannot localize deep bass tones (detect where the sounds are coming from) with frequencies below about 80 Hz.
    With the deep bass soundwaves being longer than any room dimension in many individuals' rooms, this means the soundwave will leave the single sub and need to travel as far as it can in the room and then reflect off the first room boundary (floor, ceiling or wall) it meets then keep traveling in the reflected direction until it meets the next room boundary. This process continues until the soundwave runs out of energy and with each subsequent bass tone launched into the room by the single sub. 
     These numerous bass soundwaves of various frequencies launched into the room by the single sub, and reflecting off room boundaries, inevitably run into each other at various angles causing what are called a Bass Room Mode at each specific room location at which they meet or collide. Depending on the specific angle at which the soundwaves meet, we perceive these bass room modes at specific spots in the room as either a bass overemphasis (bass peak), a bass attenuation (bass dip) or even a bass cancelation (bass null). The result is an overall perception of the bass from a single sub as uneven, not detailed, somewhat disconnected and not natural.
    However, when a second sub is properly deployed and positioned in the room, the very interesting and useful principles of psychoacoustics (how our brains process sound and our perceptions of it) begin to come into play, which results in a perception that the bass is smoother, more detailed, better integrated with the main speakers and more natural or realistic.
      Unexpectedly, this is accomplished through the second sub actually significantly increasing the number of bass room modes (bass peaks, dips and nulls) in the room. Our brains naturally and fortunately process the presence of multiple bass soundwaves below 80 Hz, by adding them together by frequency and averaging them out. This results in fewer bass modes being perceived in the room and a perception overall that the bass is smoother, more detailed, better blended with the main speakers and more natural.  
    Acoustical experts, such as Dr. Earl Geddes, Dr. Floyd Toole and others, have proven scientifically that in-room bass performance perception improves as more subs are added to virtually any given room, beginning with two subs and with improvements continuing up to the theoretical limits. Of course, there's a practical limit to the acceptable number of subs in a domestic room.
    I'm fairly certain the exact number of subs considered acceptable in a domestic room is higher for most men than most women but, interestingly, the scientists found significant bass performance perception gains were attained with each additional sub up to four but smaller more marginal gains were attained with each additional sub beyond four.
     Three properly positioned and configured subs in a given room typically provides bass response at a designated listening seat that's approaching the optimum quality level attainable at a single listening position. Three subs provide even further increased bass output capacity and impact as well as further increased bass dynamics due to the sharing of total bass requirements between three subs operating well within their limits and stress free with very large power reserves for sudden bass output dynamic demands.
     Psychoacoustic principles are more strongly applied with the use of three subs, as opposed to two subs, in any given room that results in the bass being perceived as even smoother, more detailed and better integrated with the main speakers.  
    My opinion is that the SVS SB-1000 (a small sealed sub with bass extension down to 24 Hz) and the PB-1000 (a slightly larger ported sub with bass extension down to 19 Hz) subs are ideal for utilizing in two and three sub bass systems because they're both very good quality, are relatively small, have all the necessary features/controls and are currently great bargains at about $500/each (slightly more for gloss black or white finishes).
    The larger and more expensive Olege,Seaton, Rhythmik, HSU and JL Audio subs may be better subs with more features but, remember, the critical factor for in-room bass performance is the quantity of subs used in the room and the quality and features of each is much less important. Besides, the reality is they're all high quality subs and room correction is not required for optimum performance on bass systems utilizing two or more subs.  
      However, if you prefer the best in-room bass performance, the Audio Kinesis 4-sub Swarm distributed bass array (DBA) system is definitely the ultimate bass system that I'm aware of. This is a complete $2,800 kit that includes four 4 ohm unamplified subs that are each 1' x 1' x 23", weigh 44lbs and have a 10" aluminum long-throw driver and a 1,000 watt class AB amplifier/controller that powers all four subs and controls the volume, crossover frequency and phase of all as a group.  
The use of a 4-sub DBA system will provide near state of the art bass performance not only at a single listening position but throughout the entire room. This is very useful if you have multiple seating positions in your room and prefer having very good audio at each position for both music and HT.
    Of course, only the designated listening position will be optimized for bass, midrange and treble response along with stereo imaging but very good full-range audio will still be provided at each seating position.
    They're also other benefits of the 4-sub Swarm DBA system. Absolutely no bass room treatments are necessary. You'd just need to incorporate room treatments for the midrange and treble response on your main speakers (first reflection points on each side wall and possibly some treatment on the front and rear walls). And these subs look very stylish in the room, kind of like hi-end wooden art gallery pedestals, since the 10" drivers face towards the nearest wall and have connections hidden on the bottom so all that's visible is three wood sides and the top in the wood of your choice. My wife usually has a small vase with fresh flowers sitting on one of the two that are visible in my room. They also make good end tables since they're an ideal height of 23 inches.  
    You also have the option of creating your own custom 3 or 4-sub DBA system, rather than using the complete Swarm system, by utilizing three to four SVS SB-1000 or PB-1000 subs at $499 each, or any three to four subs you'd like. I also believe adding one or two PB-1000 subs (that extend down a bit further than the SB-1000's 24 Hz to about 20 Hz) to your system would extend the perceived bass in your room down to about 20 Hz.
    The only down side of using a custom 3-4 sub DBA system is that you need to configure the volume, crossover frequency and phase settings individually for each of any self-amplified subs used rather than once for all four subs as a group on the Swarm system.
    As I've stated, I use the 4-sub A K Swarm system in a 23'x16'x8' room with Magnepan main speakers and it works like a charm. But, while I haven't personally tried it to verify, I believe three subs would perform nearly as well, especially at a single designated listening seat.

Hope this helped you a bit,
                Tim
rauliruegas:
"Even the AK SWARM manufacturer/owner posted in this forum:

""" You can get good bass in one sweet spot with two equalized subs """. Not 3 or 4 but TWO.

Obviously that for him the 4 SWARM is not his personal " religion " and he is the man behind the AK sales ! ! !

R."


Hello rauliruegas,

     Easy, I completely agree and said so on my first post on this thread.  Here's a direct quote of my initial post:

"Everything millercarbon stated is true, a 4-sub distributed bass array is the best solution. However, in a home office environment in which I'm assuming you'll be listening primarily from your desk chair, I think a pair of SVS-SB1000 subs, currently on sale for 1/2 price at $499 each and $950 for a pair, will provide very good bass performance, if properly positioned in your room, that will also integrate or blend with any pair of main speakers used. There's absolutely no need to use the same brand subs as your main speakers and you're going to save at least $7,000.
    Here's a link to the SVS website and the SB1000 subs:"

     Calm down, everything's going to be okay.

Tim
Hello rauliruegas,

     You really need to chillax, my friend, you might burst something important.  
     Didn't you read my last post stating I agree with you?  More specifically, I believe that the Swarm DBA system is an exceptionally good bass solution for music and HT but may not be the best solution for everyone.  I think each individual's bass requirements, room and system circumstances and budgets create unique situations that deserve unique bass system solutions.  
     I know high quality, large and expensive subs are not always necessary for good overall performance but also understand using better quality subs normally can only improve results.  I agree that low sub distortion is important, there are many good subs on the market and good bass performance can be achieved using one or more subs in a given room provided they're positioned and configured properly.

     My intent for this post was to make it crystal clear that I agree with you and then request you just cut it out. Agreed?


Thanks,
  Tim
cleeds:
"noble100
"You’ve already acknowledged that there are zero commercially available music recordings on any format with stereo bass content below 80 Hz, since you’ve previously stated you had to revert to recording your own content with stereo bass below 80 Hz.
cleeds: "I never, ever said that. Ever." 

Hello cleeds,

You never stated this, ever? This is a direct quote from your previous post on 8/12/19: 
cleeds:
"It’s amazing how just how common the "all bass is monophonic" canard is and how reluctant some audiophiles are to reject it. After all, it can be resolved by listening, especially if you make your own recordings."


Tim
cleeds:
"It’s amazing how just how common the "all bass is monophonic" canard is and how reluctant some audiophiles are to reject it. After all, it can be resolved by listening, especially if you make your own recordings.

I’m not the one who posted Vandersteen’s observations, but Google shows this quote came from Vandersteen’s own website. (Scroll down towards the bottom of the page.)

There is a lot of research into sound and directional cues, including LF. It’s puzzling how hard some will work to deny or ignore it."

Hello cleeds,

Very interesting that you responded before tyray and that the supposed direct quote from Mr. Vandersteen is actually from his website’s promotional information for the 2W subwoofers.

I read the linked website info and it reads more like the work of a professional advertising copy writer promoting a client’s product that he doesn’t completely understand, which is actually the case, than a knowledgeable and experienced speaker designer sharing his expertise on how his subs are able to take advantage of his knowledge of speaker design and how bass soundwaves behave in a typical home room environment to provide high quality bass reproduction.

The quote from the Vandersteen website referred to by tyray and yourself, listed below, contains too many errors for me to believe that Mr. Vandersteen would vouch for its accuracy. It seems much more likely the numerous errors are the result of an advertising copy writer plying his trade on a subject and product he has a general lack of knowledge about. I seriously doubt Mr. Vandersteen even scrutinized the content of this promotional quote since I doubt he would approve this much misinformation. I’ll explain the errors and my reasoning below after the advertising quote.

"Mono or Stereo Bass

There are significant advantages to using two subwoofers. Modern sources such as streaming, CDs, DVDs, digital high-resolution music files, and Blu-ray Discs maintain full stereo separation to below 20Hz. Summing the channels into a single subwoofer reduces or cancels all the low-frequency information containing phase differences between the channels. Stereo subwoofers reproduce all of the bass information complete with the phase differences that help provide the imaging and location cues we use to place people and things at distinct points in the sound field. Stereo subwoofers also improve linearity on mono as well as stereo sources by coupling the bass to the room at two points and lend themselves to natural placement near the corners where low frequency room gain is often desirable."

1. "Modern sources such as streaming, CDs, DVDs, digital high-resolution music files, and Blu-ray Discs maintain full stereo separation to below 20Hz."

This is the exact opposite of the truth and Mr. Vandersteen would surely know this but an advertising copy writer likely would not. The truth is that acoustical engineers and experts have known for decades that humans are unable to localize sounds (determine where the sounds are originating from) below about 80 Hz and humans absolutely cannot localize sounds below the human deepest audible bass tone limit of 20 Hz. Acoustical scientists have also known for decades that humans are progressively bettert at localizing sounds as their soundwave frequencies increase from about 80 Hz all the way to the human audible treble tone limit of 20,000 Hz.

The reality is that not only can we not localize bass tones below about 80 Hz, the fact is that there are absolutely no modern sources such as streaming, CDs, DVDs, digital high resolution music files and Blu-rays that maintain full stereo separation to below 20 Hz, all of these recording methods sum the entire bass content to mono below about 80 Hz.

What a shame, cleeds. Even if you were the only known human in the history of humans to be able to localize bass below about 80 Hz as you claim, and even if acoustics, physics and neurologic scientific facts didn’t prevent there from being such a thing as stereo deep bass, it still wouldn’t really matter since there are no recordings that contain stereo bass below 80 Hz, anyway. Don’t believe me? Then name a single commercially available music recording, of any music genre, on any recording format and recorded since the beginning of life on earth that has any stereo bass content below 80 Hz.

But wait a minute, oh yeah, you already stated: "After all, it can be resolved by listening, especially if you make your own recordings."

Make your own recordings? Recordings of what? You and your buddies garage band, The Didgeridoo and a Tuba Quartet, practicing on your tuba and 2 didgeridoos? Awesome, what else have you got?

https://www.youtube.com/watch?v=QUGytDzsgew

So, where does all this leave us on the whole subject of does deep stereo bass exist?

1. All existing scientific evidence has declared very decisively, convincingly, emphatically, undeniably, honestly a bit sarcastically and loudly through a bullhorn on full volume with fresh batteries: No Flipping Way!

2. You’ve already acknowledged that there are zero commercially available music recordings on any format with stereo bass content below 80 Hz, since you've previously stated you had to revert to recording your own content with stereo bass below 80 Hz.

3. True stereo deep bass below 80 Hz therefore does not exist but, here's the good news, individuals using multiple subs run in mono mode will still perceive the bass in stereo due to psychoacoustics. Here’s how it works:

The fundamental bass deep bass tone on a 20 Hz recording will be reproduced by the multiple mono subs and will not be able to be localized. However, these deep bass tones also have bass harmonics or overtones that will extend in frequency above 80 Hz (the bass localization threshold) that are reproduced in stereo through the main speakers.and are able to be localized. Our brains are fortunately able to associate these higher frequency harmonics/overtones with the related fundamental 20 Hz deep bass tone and, as a result, determine where the deep bass tone originated from in the soundstage illusion. For example, the bass drum is perceived as being at the rear center of the soundstage and the upright bass is perceived as being at the front left side of the soundstage. This is an example of a psychoacoustic effect. Psychoacoustics is the study of how the brain processes inputted soundwave information from the ears and forms our perceptions of sounds.

Cleeds, I believe you are experiencing this psychoacoustic effect on deep bass fundamental frequencies below 80 Hz on your system and assuming that humans are able to localize deep bass tones this deep. We’re not consciously aware that the higher bass harmonics/overtones frequencies above 80 Hz are the clues our brains actually need and utilize to localize deep bass tones. It’s our amazing brains, with the assistance of higher frequency bass harmonics/overtones, that are actually responsible.

I think you made a logical assumption and hope you agree this distinction is the likely cause and explanation of our disagreement on the existence of true stereo bass below 80 Hz.

Thanks,

Tim



Hello mijostyn,

     Was that a legit scientific experiment with published results you could refer me to? If so, my thinking that locating deeper bass tones (below 50-60 Hz) still requires the assistance of higher frequency bass harmonics above 80 Hz for localization is still valid but will need revising downward from 80Hz. I wonder what % of humans can locate bass tones down to 60 Hz?

Thanks,
  Tim
cleeds:
"noble100
You never stated this, ever?
Correct. I never stated there "are zero commercially available music recordings on any format with stereo bass content below 80 Hz" or that I "had to revert to recording (my) own content" to get stereo bass below 80 Hz.

I’m not sure why you keep insisting that I said that, but you’re free to believe whatever you like."

Hello cleeds,

My point or question is what did you mean when you posted this?:

"It’s amazing how just how common the "all bass is monophonic" canard is and how reluctant some audiophiles are to reject it. After all, it can be resolved by listening, especially if you make your own recordings."

Specifically, why would you state: "After all, it can be resolved by listening, especially if you make your own recordings."

It makes it sound like you couldn’t just play any commercially available recording that, according to you, generally have recorded stereo bass below 80 Hz. Then you don’t just state the question over whether stereo bass below 80 Hz actually exists or not can be resolved by listening to any commercially available recording, but you qualify it by adding "especially if you make your own recordings."
I’m not even sure what this means exactly. What are you recording? Commercially available music from another source or your garage band live? What recording device, what recording format, what is the format’s recording resolution and frequency range capability?

Thanks,
 Tim
Hello Hans,

     I just wanted to let you know that taking any of tyray's advice on his last post is done at your own peril.  There's so much bad advice and false information in his post that it would take me hours to catalog them all and explain each of them to you.  Unfortunately, I don't currently have the time to do this.  So, I suggest you're better off just disregarding his entire post
     He obviously lacks the knowledge and experience required to be giving good information or advice to anyone about attaining good in-room bass response performance.  I believe he just doesn't know what he doesn't know.
     From what I could learn online, your Ologe 5 are high quality speakers that are just lacking high quality low frequency output below about 48 Hz.
    I have no doubt that your overall office system sound quality performance will be significantly improved by a single good quality sub, properly positioned and configured, since it will provide the missing frequency range from 20 to about 50 Hz.  But my experience is that 2 subs will sound twice as good as 1 sub and 3-4 subs will sound twice as good as 2. 
     The reasons multiple subs perform so well is due to the total bass output duties being shared so that no single sub is operating near its limits, the combined bass power and impact being increased, there being increased power reserves for better bass dynamics and the presence of multiple points in the room producing bass results in the perception of smoother and faster bass response that better integrates or blends with the main speakers' midrange and treble output.
    In your situation, I would describe your choice as between good, better or best.  In other words, between 1 sub, 2 subs or 3-4 subs. 
     If you're currently unsure or don't want to take a risk, I'd suggest a good way to begin is with 2 SVS SB1000 subs, 2 SVS PB1000 subs or one of each because I'm certain this type of sub setup will deliver significantly better overall sound quality performance,  costs $1,000 or less with no shipping costs, allows a 45-day free in-office trial period and, if not completely satisfied with their performance, offers a full refund with free return shipping.  
     I understand you've decided to take some time to get your room straightened out.  When you're ready and whichever option you eventually choose, however, I'm still willing to help you with step by step procedures for optimum sub hookup, positioning and the setting of sub volume, crossover frequency and phase settings.  Just send me a pm when you're all set.

Later,
Tim

    
  
Hello rauliruegas,

     Regarding bass phase and recordings not done with only 2 mics or CDs with out of phase bass, my opinion is that we really have no control over that and can't do anything about it except avoid listening to poorly recorded music content.

     Regarding whether we can localize bass under 80 Hz using our ears and brains or any other body parts, I know I can often feel sharp 55 Hz strikes on a kick drum with my body but it doesn't inform me where it came from within my system soundstage. I believe I perceive the kick drum, that I can feel and hear, as being located in the rear center of my system soundstage because of the higher frequency harmonics/overtones of the 55 Hz fundamental tone, that reach above 80 Hz that we are able to localize, and our brains are able to relate or associate them to the fundamental tone of the kick drum strike and determine its location within my system soundstage.  In other words, we are only able to localize fundamental bass tones with frequencies below 80 Hz if the harmonics/overtones related to that fundamental deep bass tone that are above 80 Hz are also heard, usually through both of our main speakers.
     I understand this is a complex thought to convey and I hope you understand what I wrote.
     I don't consider this true stereo deep bass but rather what I've termed Psychoacoustic Phenomenon Psuedo Stereo Deep Bass.

    I agree with you that using better quality subs will only improve the quality of bass reproduced.  I think this is true whether one uses a single sub or multiple subs.

Tim
Hello Duke,

     I'm glad you chimed in and shared your knowledge. 
     If you don't mind and have the time, I was hoping to get your honest opinion on my thoughts on how I understand multiple sub systems function in general as well as my understanding of how bass is recorded on CDs and vinyl.  Basically, I'm asking if you agree with my summary below?    
     
       We all are unable to localize deep bass frequency soundwaves, that is determine where the sound is coming from, that are below about 100 Hz but we're very good at localizing higher frequency soundwaves in the remainder of the audible spectrum, from about 100 to 20,000 Hz.
    This is the reason there's no such thing as 'true stereo' deep bass and why the bass is summed to mono on frequencies below 100 Hz on all vinyl and cd recordings. If you doubt this, try to find a single vinyl or cd recording that is not summed to mono. This means it's pointless to configure subs in a stereo configuration with one located by the left main speaker and one by the right.
    However, thanks to psychoacoustics and our remarkable brains, it is possible to create the perception of stereo bass in our systems. Here's how it works:
    Whether you use 2, 3 or 4 subs, run them in mono and optimize the bass at your listening seat. The bass below 100 Hz won't be able to be localized but there are bass harmonics or overtones of the deep bass fundamental frequencies that extend into higher frequencies that are reproduced by the main stereo speakers and can be localized. Our brains are able to associate the fundamental deep bass frequencies reproduced by the subs, that are not able to be localized, with the deep bass's higher harmonic frequencies, that extend well beyond 100 Hz, which are reproduced by the main speakers that are able to be localized. This psychoacoustic association allows us to localize the deep bass in the soundstage, for example the kick drum is located in the rear center and the upright bass is located in the front to the left, which would not be otherwise possible without this psychoacoustic association our brain's are capable of.  


Thanks,
Tim
Hello millercarbon,

     Very good post, well worded, sincere and I definitely know it's honest and accurate.  I think Duke helping you with advise even though he knew you were building a DIY clone of his 4-sub Audio Kinesis Swarm system was unexpected, unselfish,says a lot about his priorities and was just very cool.

Enjoy,
Tim   
Hello rauliruegas,

       Did you read the responding post I directed to you yesterday 8/15/19?  If not, here is a direct quote addressed to you from my earlier post:
"I agree with you that using better quality subs will only improve the quality of bass reproduced. I think this is true whether one uses a single sub or multiple subs."

     I appreciate, respect and understand the importance of good quality in almost everything, especially in things I decide to purchase or am considering purchasing.  What I don't appreciate, respect or understand is why you believe you made it clear to me, with my own facts and statements, that my system is of poor quality.  I must have missed that deftly executed revelation you so kindly presented to me, using my own words no less.  Well played, mi amigo, well played.

Later,
Tim
Duke,

    Thanks for taking the time to review my thoughts on multiple subs. I'm glad you validated my understanding, with the 80 Hz revision, since my thoughts are all reflections of my personal experiences using your 4-sub DBA system.  
    You stated:
"I wouldn’t say "all", but I would say "almost all". (If we’re talking about a Swarm/DEBRA system, a second amp can be added to give you true stereo bass)."

    Is there such a thing as true stereo bass? I'm still a little fuzzy on this issue. I run all my subs in mono and perceive true stereo bass on all recordings regardless of format. This is due to the process I mentioned in my summary, of our brain's ability to associate the fundamental deep bass frequencies reproduced by the 4 subs in mono, that are below 80Hz and not able to be localized, with the deep bass’s higher harmonic frequencies, that extend well beyond 80 Hz, which are reproduced by the main speakers that are able to be localized. This is what I'm currently experiencing on my system that I would describe as true stereo bass.

Are you making a distinction between the perceived true stereo bass that I'm currently experiencing and your mention of "a second amp can be added to give you true stereo bass"?

Also, when I asked you whether the bass is summed to mono on frequencies below 100 Hz on all vinyl and cd recordings?   

You said you wouldn’t say all, but almost all.   On several other threads  no one, including myself, was able to name a single recording on any format containing true stereo bass.  Are you aware of any?


Thanks again Duke,
     Tim
audiokinesis:
"The point is not whether there is an unrealistic test condition in which a distrubuted multisub system falls short. The point is, how does it perform when used under normal conditions?

Duke"
Hello Duke,

     Yes, I believe that's the goal of most of us if not all of us: 
"How does it perform when used under normal conditions?"

Rauliruegas,

     As I've stated, the AK Swarm/Debra 4-sub DBA system performs exceptionally well in my 23'x16'x8' room and seamlessly integrates with my fast and detailed Magnepan main speakers (which for years have been infamous for being difficult to integrate well with conventional subs) for both 2-ch music and HT.  
     My main concern is music and I don't think I can overstate how well it performs on all of my CDs and it performs even better on my high-resolution 24bit/96KHz direct to digital FLAC music files.  
     This combination transports me to a fairly wide and deep 3D soundstage in my living room of the musicians and the recording venue, usually jazz or blues in a small club or Sound Liason's larger European direct to digital recording studio,  that's ultra-realist sound quality, I believe, can be largely attributed to the bass quality, impact and dynamics that's normally only experienced with music heard live and in person.  Thank you, Duke.
     I consider this state of the art bass performance but I understand that similar results can be achieved at a single dedicated listening position utilizing two high quality subs that are properly positioned and configured, like the approach you chose.  Here's a link to a Todd Welti, of Harman International, that confirms this:

https://www.harman.com/sites/default/files/multsubs_0.pdf

Later,
Tim  
Hello audiorusty,

The use of a distributed bass array (DBA) system is a very good solution for distributing low bass evenly throughout the entire room. Unfortunately, there’s not currently an equally effective solution that will distribute the mids and highs throughout the entire room, at least not while maintaining good stereo imaging throughout the entire room.
Since using and understanding the exceptionally high quality bass performance of a DBA system, I now view my system as two systems, a bass system and an ’everything else’ system, with ’everything else’ meaning the mids, highs and stereo imaging.
I recommend installing the bass system and getting that performing optimally first since it has traditionally been the hardest system aspect to get sounding right in most home systems, due mainly to the extreme length of bass soundwaves and how this results in audible bass issues in domestic sized rooms, and because high quality bass is the solid foundation that most music and high quality home audio systems are built upon.
Once the bass is performing optimally in the room, the next priority is to position the main speakers, in relation to the dedicated listening seat, to optimize the midrange, treble and imaging performance. This has traditionally been a much easier system aspect to get sounding right in most home systems, due mainly to the much shorter length of these midrange and treble soundwaves and their resultant highly directional nature. All that’s normally required is precise positioning, including toe-in angles, along with room treatments to control the first reflection points and perhaps some room treatment along the front and back walls.
All soundwaves of all frequencies reflect or bounce off of room boundaries (floor, walls and ceiling) until they run out of energy and collide with themselves and other soundwaves along their reflected paths within any given room. However, when bass soundwaves collide it’s perceived as a bass peak, dip or null, while when midrange and treble soundwaves collide it’s usually perceived as an airy quality except when they have a negative effect on imaging at the designated listening seat.
The final steps are directed at integrating or blending the bass system’s sound with the ’everything else’ system’s sound as seamlessly as possible. This is accomplished through precisely adjusting the volume, crossover frequency and phase control settings collectively for all four subs on the amp/control unit for an AK Swarm or Debra DBA system or individually for each of the four subs on a custom DBA system.


Tim
raulruegas:
"Fortunately I already made my choices on room/system choosing what for my MUSIC/sound priorities, still today, gave and give me the best trade-offs for a high quality overall level performance. Truly satisfied, not " perfect " but always perfectible."


Hello rauliruegas,
     
      You're obviously very fortunate.   You made an informed choice and picked the set of tradeoffs that makes you happy.  
     Congratulations, you only have one thing left to do; enjoy the heck out of your high quality system with your music of choice.

Enjoy,
Tim
Hello Mike,

     I usually crossover my four Swarm subs at 40 Hz for music and HT but sometimes as high as 50 Hz.  According to your method of 1/2 the length of the crossover frequency, this would mean my subs should be no more than 14 feet apart at 40 Hz and no more than 11 feet at 50 Hz.
    My room is 23'x16'x8' with my main speakers (with bass extension rated at 35 Hz +/- 3db) along the 16' wall and run full-range. Two of my subs are along this 16' front wall with each about 2' away from the nearest corner and about 6' apart from each other.  The other two subs are located, one each, along the left and right 23' walls and each about 3' away from the corners along the rear 16' wall.  This results in my rear subs being about 16'apart from each other and about 20' apart from the nearest sub along the front 16' wall.  So, since some of my subs are more than 14' apart and exceed your rule of thumb, you're suggesting I should have bass phase issues in my room.
     The Swarm amp/control unit does have a continuous phase control adjustment.  I set this by inverting the phase on both of my main speakers and setting the phase control to the position at which the bass sounded the weakest at my listening seat.  I then reattached the speaker wires to in-phase and the bass sounded equally very good throughout my entire room and at the 6 seating positions in my room.  Do you think this is why I don't detect any obvious bass phase sound quality issues in my room?
    Although I've never heard one, I do understand from what I've read and from your comments that subs configured in a line array are capable of even better bass performance than subs configured in a distributed bass array.  However,  my music listening and HT room also doubles as my living room and devoting the entire 16' wall of my living room to a line of subs is not practical. I'm not stating I disagree with the high quality bass capability of a line array bass system.  I'm just stating that I'm willing to sacrifice optimum bass response performance in my room for the extremely good bass response performance of a distributed bass array that blends much more inconspicuously in my living room.  

Tim
Hello Mike,

    You stated: "Simplifying the situation, what Duke is saying is that placing subs randomly throughout the room creates a situation that smooths out the frequency response throughout the room. I am trying to understand how that happens. "

    Hopefully, Duke will respond, too. But as I understand it, the key to understanding how and why a distributed bass array (DBA) smooths out the bass frequency response is psychoacoustics, how the brain processes bass information in the room delivered through the ears, as well as through other body senses, and creates our perceptions of the bass.  
    The purpose of four independent, well distributed subs launching bass soundwaves into the room, with the full knowledge that these soundwaves can be relied upon to reflect off room boundaries and collide into themselves and one another until they run out of energy, is to create an abundance of bass room modes (bass peaks, dips and nulls) and then depend upon our brains to process, sort and make sense of the abundance of room modes in order to create an overall perception of the bass in the room. In other words and simpler terminology, psychoacoustic principles, which explains how the brain will sum the bass by frequency and average it out which results in our perception of the bass as smoothed out and natural.
    I believe psychoacoustics are the key to understanding why and how the DBA concept works so well. It seems to me that explaining how and why a line source bass array (LSBA?) concept works so well can be done more easily with just physics than the DBA concept can and the LSBA concept seems to rely much less on psychoacoustic dynamics than the DBA concept does.  I think psychoacoustic principles and dynamics are a bit esoteric and counterintuitive.
    I've never experienced the bass response performance of an LSBA system in any room. I know the first time I experienced the bass response performance of a DBA system in my room it was a revelation and uncanny how well it performed.  I'd love to experience a LSBA system some day soon since I believe it could also be a revelation.
     I share your curiosity about whether I would detect any difference in bass performance with my DBA by limiting the distance between subs to under 14 feet.  However, in 2008 I had a stroke and still don't have full mobility of my left arm and leg.  I also had custom length speaker wires made for all four subs and the wiring is all run and hidden in the crawl space below my room.  Due to these factors,unfortunately, I don't think it's practical for me to experiment anytime soon.  Perhaps I could recruit a fellow audio enthusiast friend as an experimental lab assistant and mover but no promises.


Tim  
mijostyn: "Tim, in this case I don't think psycho-acoustics is the reason."   "when a concept is counter intuitive it usually means it was not explained well."

  Hello mijostyn/Mike,

    I think we have different ideas concerning what qualifies as psychoacoustics.  Psychoacoustics is the scientific study of sound perception and audiology—how humans perceive various sounds. More specifically, it is the branch of science studying the psychological and physiological responses associated with sound (including noise, speech and music).  I think you're right, masking and volume could be construed as part of that definition, they're just not the primary examples that I usually think of.
    I also believe my explanation of the DBA concept and the psychoacoustic dynamics involved was sufficient. 
 
    When I stated the DBA concept is counterintuitive I was referring to the method of creating more bass peaks, dips and nulls in the room to eliminate the perception of all of them in the room, with our brains being used as a sort of natural room correction software and hardware.  
     Do you think the DBA concept is intuitive?  
     Don't you think the cognitive dynamics involved with the DBA concept fall within the definition and realm of psychoacoustics? 

     You're correct, Geddes has stated that good in-room bass response can be attained over a wider area using as few as three subs and good at a single listening position using just two.

     Hopefully, Duke will respond to the bass phase issues.  

    You have no rear wall in your room for bass soundwaves to reflect off of? You must have very good bass performance along with very high heating and cooling costs.


Tim
Hello Mike,

     If you're intuitive, you can probably guess what this word means just by looking at it. No? Maybe you're not so intuitive, after all. Intuitive means having the ability to know or understand something without any direct evidence or reasoning process. Your statement that "Now that I know what is going on it makes perfect sense and is indeed intuitive"   defies logic; the very fact you required more information to fully understand the DBA concept proves it is NOT intuitive. I don't understand why you felt the need to rebut my statement that the DBA concept is counterintuitive, when it obviously is, but I suggest we just drop the whole subject and move on.

    Thanks for explaining what you meant by having no rear wall, I get it now.

    You stated: "I firmly believe that with any dipole speaker, Planar magnetic, ribbon or ESL you have to cross up higher at least at 100 Hz. This disqualifies a DBA. On the other hand my way of doing things may not work well with regular dynamic speakers. Pick your poison:)"
    We seem to have different audio experiences and opinions but I think that's healthy since we both can benefit by discussing our differences. Even though you utilize a line source bass array system (LSBA) and I use a distributed bass array system (DBA), I believe it's a win-win scenario because we've both attained exceptionally good bass response performance in our rooms/systems along with also learning more about an alternative bass system solution.
     In the spirit of benefiting from discussing our differences, I disagree with your statement that planar-magnetic dipole speakers need to use crossover frequencies of at least 100 Hz.   I have planar-magnetic, dipole, 3-way Magnepan 2.7QR mains but they have decent bass extension, rated at 35 Hz +/- 3db. I run them full-range and usually cross them over to the 4 Swarm subs in the DBA at 40 Hz. This works very well in my system/room with the bass seamlessly integrated with my main speakers without any downside I'm aware of.
     I think I understand your reasoning for suggesting using higher crossover frequencies on planar-magnetic, ribbon and electrostatic speakers.  These speaker types don't typically have very deep bass extension and freeing both the speakers and the amp(s) driving them from the demanding requirements of reproducing deep bass are logically reasoned to improve the performance quality of both as a result.
    This theory makes so much sense to me that I experimented with using crossover frequencies at various settings as high as 100 Hz,  both with filtering out the low frequencies below the crossover setting and running the mains full-range.  I stopped experimenting with higher crossover settings once I began perceiving the location of the subs at around 100 Hz and it began to have a negative affect on the normally very good stereo imaging of my mains.
     I believe my system didn't gain the expected sound quality benefits of reducing the low frequency demands placed on my amps and speakers due to a couple of reasons.   The first reason is the Magnepan 2.7QR mains I use are a 3-way design with rather large 625 square inch dipole bass sections that reproduce frequencies from their lower limit of 35 Hz to  650 Hz.  But relieving these bass sections of reproducing the deepest bass frequencies in this range had no significant affect on the midrange and treble sections of these speakers. Also, any significant sound quality improvements in the bass sections' performance would be masked by the high quality bass reproduced by the Swarm bass system.
     The second reason is that the D-Sonic class D mono-block amps I use for the mains deliver 1,200 watts into the Magnepans' fairly consistent 4 ohm loads.  However, I still believe that systems using less powerful amps and speakers with simpler. less than 3-way, designs could realize  significant overall sound quality improvements.
     After extensive experimentation, I actually arrived at the opposite conclusion than you recommend, at least for my system.  I thought my system sounded the best overall with the main speakers running full-range and the Swarm subs only becoming active on frequencies at or below a relatively deep 40 Hz and when the source content called for it.
     I believe my system may perform even better overall with an even lower crossover frequency setting but 40 Hz is the lower limit on my sub amp/control unit.
     My current thinking is that there are a number of good bass system solutions available, beginning with a pair of good quality subs, and that the choice of the optimum bass system, as well as its optimum configuration, is best determined on an individual basis.

Later,
Tim

  
     
      
Hello Hans,

     Clio09 is correct, both the Audio Kinesis Debra and Swarm 4-sub DBA systems are very similar and perform almost identically. James Romeyn and Duke Lejeune are friends and are business associates in Audio Kinesis.
James is located in Utah and, as I understand it, he licenses the Audio Kinesis brand name for his Debra 4-sub DBA system with Duke’s approval. Duke owns Audio Kinesis, is located in Texas and designed, manufactures and sells his Swarm 4-sub DBA system.
     Both are excellent systems, use an identical amp/control unit and use identical 10" aluminum long-throw woofers in their subs. However, I believe they both have local third party woodworking companies build the actual sub cabinets and assemble the subs. I believe this is the reason the Debra subs are a few inches taller and wider than the Swarm subs.
     They both come with removable port plugs that allow configuring them as either sealed or ported subs, soft rubber footers for hard surface flooring and spiked metal footers for carpeted flooring as well as having the speaker wire connections located on the bottom for concealing the connections for a clean look. These subs actually are designed for the front firing woofers to face, and be only a couple of inches away from, the nearest wall. They all perform great this way and all that’s visible are nice clean pedestals in the wood of your choice.
     I just happened to initially learn about the 4-sub DBA concept through conversations with James and, as a result, decided to purchase and give his Debra system a free 28-day in-home tryout before ever even knowing of Duke’s Swarm system. I’d also recommend calling either or both James and Duke to discuss your specific situation. They’re both very friendly, knowledgeable and helpful.

Best wishes,
Tim
Mijostyn: "According to Earl Geddes... you want to keep your subs as far apart as possible and throw the fourth one away."

Duke:"The four-sub configuration I use was Earl’s first-generation multisub-system. He subsequently wrote a program that can analyze the outputs of three subs and design custom digital equalization filters that will attain his goals without needing that fourth sub. The drawback is, if you move any of your subs or buy a new sub or change rooms, you need to have Earl redo the equalization in order to return to optimization."


Hello Mike and Duke,

      Even though I don't doubt Earl Geddes when he now states three subs are sufficient to constitute an effective DBA, I know there are other benefits of utilizing four subs in a DBA system in my room; namely the sense of bass ease along with the sense of the natural and unlimited bass power and impressive bass dynamics of music that I normally only perceive with music I hear played live in person.  I wouldn't want to sacrifice that quality just to have one less inconspicuous sub in my room. 

Tim 

    mijostyn,

     Oh yeah, sorry, I forgot you use a 4-sub line source bass array system.  Well, then I'm sure you understand exactly what I mean when I describe a 4-sub bass array system as having a sense of bass ease that gives the impression of unlimited and natural bass power while also being capable of reproducing the impressive bass dynamics of music that one normally only perceives with music one hears played live in person. I'm also fairly certain you wouldn't want to only use only three subs, either.

Tim
Hello Hans,

     I recall James and Duke agreeing that the 4-sub distributed bass array(DBA) concept actually works very well in small rooms.  It's a bit ironic since multiple sub bass systems in small rooms are probably one of the least likely solutions most individuals would logically consider as a viable solution.  
     I don't believe there're set limits to domestic room sizes, floor materials or ceiling heights that a DEBRA/SWARM system will be effective in, it's more a matter of accommodating four 1' x 1' x 2' subs along the perimeter of the room facing the nearest wall.  The main goal, counterintuitively, is to get as many bass modes (peaks and dips) distributed throughout the room as possible and rely on our brain's normal functioning to create the perception of smooth, detailed  and natural bass that seamlessly blends with the main speakers. The concept works exceptionally well in virtually any room and with any pair of main speakers.  

     I think either James or Duke will offer an in-room home trial period, as James did for me, to make sure your room isn't one of the extremely rare rooms and systems it does not perform exceptionally well in. This makes it a very low risk purchase and it'll all be needless anyway since your room has no obvious issues. I'm fairly certain you'll be very glad if you decide to give either one a try.

Tim  
mijostyn:"Actually, it might work better in a small room. Every dimension in a room makes difference but perhaps less so with multiple subwoofers."


  Hello Mike,
     
     I believe you're correct.  Very few people probably even consider, much less attempt, using multiple subs in a small room and are unaware this would be a good bass solution.

Tim


 Report this
    
audiokinesis:"I’m working in a small-room optimized speaker system and surprise surprise it includes four small subs, two of which are built into the bottoms of the main speakers for the sake of practicality."

Hey Duke,

     Very interesting.  As I understand it. having main speakers with subs built-in can be an issue since main speakers are typically positioned in the room to optimize the midrange and treble response, along with the  stereo and soundstage imaging, at the designated listening seat.  This means the built-in subs, because they are housed in the same cabinet as the midrange and treble drivers and are restricted to being positioned at the exact same room positions as the midrange and treble drivers, which are unlikely to be the exact optimum sub room positions in the room for bass response performance at the designated listening seat.
     Because I believe you know all of the above, I'm thinking your purpose for these two built-in subs is probably just to create numerous bass modes (peaks and dips)in the room. 
      Is your new small room concept based on the reasoning that placing the first two subs at the predetermined locations where the midrange and treble drivers perform best will typically be placed sufficiently that, with the additional two subs being capable of being placed optimally in combination with the two predetermined subs. the overall bass response in the room will be generally not be optimized but still exceptionally good?
     If so, is the reason for not using four independent subs along with a pair of independently positioned and matched bookshelf type satellites just practicality?

Just curious,
     Tim

     Hello Duke,

     Thanks for the clarification, it all makes a lot of sense to me. 
     It seems like your new system concept will probably work well not only in a variety of small rooms, but also some medium sized rooms.  Plus, I'm sure you won't mind having a speaker system that has the very convenient and useful added benefit of working well in a hotel sized room.  

Tim
    
Hello mijostyn/Mike,

     You’re going to hate this, but I agree with you that most wives don’t like tripping over subs in big boxes/cabinets and are generally more concerned with aesthetics than their husbands. We men generally seem to have more utilitarian and porcine natures.
     My wife is no exception and we both actually appreciate good aesthetics in our home décor; no feminine or interior decorator jokes at my expense, please. We were both pleasantly surprised on how stylish the DEBRA subs are and how well the four subs blended so well with our living room decor. I suspect the SWARM subs are equally attractive since, once the DEBRA and SWARM subs are properly installed with the speaker wire connections on the slightly elevated bottoms and with the drivers facing the nearest wall, they look like attractive wooden pedestals that are typically found in fine stores, art galleries and museums to display objects.
     My wife usually has a vase of fresh flowers on one or both of the two subs that are visible toward the rear of our living room. The front two subs along the front wall, are each hidden from view behind a 6’ x 2’ Magnepan speaker panel.
     Overall, both our good aesthetics and very good bass sound quality performance requirements have been completely met by the DEBRA 4-sub DBA system in our more medium sized 16’ x 23’ sized living room.
I believe that either the DEBRA or SWARM 4-sub DBA systems would meet or exceed most individuals’ expectations in any room that can accommodate the four relatively small (approximately 1’ x1’ x 2’) subs. If anybody has such a small room that they have concerns about fitting the four subs, however, it sounds like Duke’s in development system incorporating two of the four subs into the main speakers, seems like a clever alternative solution to satisfy a likely niche market.
     My main concern is to what degree would the extremely good bass power, impact and dynamics qualities of the four separate subs configuration used by the SWARM and DEBRA systems would be compromised when two subs are incorporated into the main speakers or smaller bass drivers are utilized.
     My main point being that I suggest that the OP, Hans, utilize the DEBRA or SWARM if he thinks the four subs can be accommodated in his small office before considering waiting for Duke’s new more integrated product to become available. My reasoning is that I’m fairly certain the bass performance will be excellent with both separate 4-sub AK DBA systems, he can continue to use his Ologe 5 main speakers that he seems to enjoy and I know the combination will blend very well with these main speakers.
     I believe he’ll be thrilled with the in-room bass performance and seamless integration with his Ologe 5 main speakers or any other main speakers he may choose to utilize in the future, using either the DEBRA or DEBRA bass systems. The main concern seems to be whether the four subs can be positioned in an unobtrusive manner in his office. Based on my experience, I think he’ll be pleasantly surprised how stylish and unobtrusive either solution would actually be.

Tim
Hello allucard and bdp24,

     I don't doubt that both the REL HT1205 and Rhythmik L12 are very good subs that work vey well in your systems.  There are also other very good subs currently available that run the gambit from relative bargains to quite expensive.
     However, the OP Hans has expressed an interest in considering the 4-sub Audio Kinesis DEBRA bass system with the four subs positioned around the perimeter of his office in a distributed bass array (DBA) arrangement.  The  4-sub DBA concept is a new one to Hans and many others, which is why many of the recent posts on this thread have concerned the concept's explanation, its effectiveness and possible further refinements.  
     In the spirit of educating others on the DBA concept, both of you mentioning alternative very good reasonably priced subs that Hans could consider using raises a very good point and relates to other important advantages of using the 4-sub DBA  concept: its flexibility and scalability.  I believe anyone considering a DBA system should be aware of these for best results.
     Its flexibility is demonstrated by the fact that effective custom DBA systems can be created using any subs an individual prefers.  Its scalability is demonstrated by the fact that the actual in-room maximum bass power, impact and dynamics can be increased and decreased according to the subs utilized as well as adjusted by the setting of the volume and crossover frequency controls.
     The essential main requirements for an effective DBA system are that four subs be used and that they're properly positioned in the room.  There is a vendor offering an effective DBA system utilizing only three subs but it requires professional positioning of the subs based on a proprietary computer program.  
     The acceptable actual subs utilized in an effective custom DBA are less restrictive and can range from using small DIY subs containing 8" drivers, like clio09 uses, to using the largest and most expensive subs available.   
     I also wanted to make sure Hans understands the practical distinctions between installing and configuring a 4-sub custom DBA system versus a complete kit DBA system like the AK SWARM or DEBRA systems.   The main method of seamlessly integrating a sub or subs  into one's system are the proper setting of the Volume, Crossover Frequency and Phase controls.  
     With a custom DBA system, using traditional self-amplified subs, all three of these settings are required to be set individually on each of the four subs. With a complete kit SWARM or DEBRA DBA system, using passive subs amplified by a separate external amp/control unit, all three of these settings are only required to be set once for all four subs as a group on the amp/control unit.  
     Another option, if you're handy and up for it, is to buy the same sub amp/control unit the SWARM and DEBRA kits use and build four passive subs of your choice.  This would allow the setting of controls once for all four subs but it could be either more or less expensive than the cost of the SWARM or DEBRA complete system, depending on the exact sub components chosen and the dollar value you designate for your own labor.

Tim
Hello Hans,

    I'm glad you went out and listened to subs at local shops in your area. It's a very good method of gaining knowledge and experience, getting an idea of costs, an understanding of sound quality performance differences between sub brands and sizes as well as determining what you like.  
    The truth is that a pair of good quality subs, properly positioned and configured, would provide very good bass performance in your office at a single designated listening position such as your desk chair behind your desk. You could also save some money by buying a pair of good quality subs online with a free 30-day in-office trial period.
    The main advantages of using the Audio Kinesis DEBRA 4-sub DBA system are that the bass will not only be even faster, smoother, more detailed, more powerful, more effortless, with better dynamics and more natural sounding overall than a pair of good subs but it will also sound like this throughout your entire office, not just at your desk chair.
    Duke has often stated something like: "2 subs will sound twice as good as 1 sub, 4 subs will sound twice as good as 2 and 8 subs will sound like good grounds for divorce to a lawyer." The 4-sub DEBRA does cost more than many pairs of subs would at $2,800 and requires a bit of a leap of faith to even try but it'll perform better and the risk is mitigated by James and Duke offering a free in-home trial period.
     Of course, it's completely your decision whether you're satisfied with very good bass response at your desk for a reasonable price with a pair of good quality subs or you're willing to spend a few hundred dollars more and achieve exceptionally good bass response throughout your entire room by using the 4-sub DEBRA.  I'm fairly certain both options would provide bass that blends very well with your main speakers.
     
     Most of your questions/concerns you posted about wiring and cables are addressed on the thread I started awhile ago on the DEBRA system linked below.

https://forum.audiogon.com/discussions/anyone-else-using-an-audio-kinesis-swarm-or-debra-distributed...

     

     The DEBRA's supplied sub amp/control unit has dual speaker output terminals, labelled as A and B, and this thread details how the final sub cabling hookups are done in a series/parallel method:

Attach a single wire from the amp’s speaker A’s pos. output terminal to Sub#1’s pos. input terminal.

Attach a single wire from the amp’s speaker A’s neg. output terminal to Sub#2’s neg. input terminal.

Attach a single wire from Sub#1’s neg. input terminal to Sub#2’s pos. input terminal.

Attach Sub 3 & 4 using this series/parallel method on the amp’s speaker B’s output terminals.

     I planned out all the wire lengths (with a small margin of error inches added to each) and ordered single, high quality and low gauge speaker wire along with the sub system for a very reasonable price from AK's James Romeyn in Utah. Once the ideal locations for the subs was determined, I drilled holes in my room’s carpeting and subflooring to the crawl space below, and was able to hide all of the connecting wires.

     Each sub comes with a set of 3 brass spiked footers for positioning on carpeted floors.  These raise each sub about a half inch off the floor which allows the clearance for the running of speaker wires to each sub's input terminals located on their bottoms.

     If you don't have a crawl space or basement located below your office to run and hide the wires, there are other options for doing so such as running them behind baseboards, inside the walls or through a drop down ceiling or an attic.  Another idea is to run the wires in a plastic conduit that could be attached to the top of your baseboards in a matching color so that it appears to be a part of the baseboards. You could probably do it yourself but it may be easier and less frustrating just to hire an electrician to do it.  I'd suggest avoiding running them underneath wall to wall carpeting mainly because it seems too permanent to me and you may have future ease of access issues to the wiring. 


Later,

Tim

Hello Hans,

Remember, connecting the 4 DEBRA subs is a bit different from hooking up regular speakers with regular spkr wire that has a pos. conductor wire and a neg.conductor wire combined side by side. With the Debra, you need to follow the procedure listed below:


The DEBRA’s supplied sub amp/control unit has dual speaker output terminals, labelled as A and B, and this thread details how the final sub cabling hookups are done in a series/parallel method:

Attach a single wire from the amp’s speaker A’s pos. output terminal to Sub#1’s pos. input terminal.

Attach a single wire from the amp’s speaker A’s neg. output terminal to Sub#2’s neg. input terminal.

Attach a single wire from Sub#1’s neg. input terminal to Sub#2’s pos. input terminal.

Attach Sub 3 & 4 using this series/parallel method on the amp’s speaker B’s output terminals.


"So after deciding on a cable management solution, should the rule of thumb be to determine the longest run of cable (to reach the farthest subwoofer) and use that length for the remaining three?"

"Am I assuming correctly that if multiple subwoofers are used, their cable lengths should be identical, as with the main speakers?"

Answers:

Connections are made using single conductor wire which is a bit different than regular speaker wire. To hookup the first pair of subs requires 3 single conductor wires: 1 wire is connected from the amp’s A pos.output to sub#1’s pos. terminal input, a second wire is connected from the amp’s A neg. output to sub#2’s neg. terminal input and a third wire is connected from sub#1’s negative terminal to sub#2’s pos. terminal. The proper length of each of these wires will depend on the distances between the amp and sub#1 and sub#2 as well as the distance between sub#1 and sub#2. You will not know these distances until you determine exactly where the amp will be placed in your office and exactly where sub#1 and sub#2 sound the best in your room.

The 2nd pair of subs also require 3 single conductor wires for hookup and you’ll need to determine exactly where sub#3 and sub#4 sound best in your room before the proper length of these 3 wires can be determined. I suggest you measure your room, decide where the DEBRA’s amp is going to be placed and then calll James Monteyn at Audio Kinesis in Utah to order your DEBRA and the 6 cables you’ll need for hookup. James will help you determine the length of each sub cable (with a bit extra added to allow for a margin of error in measurement accuracy) as well as the interconnects between your amp and the DEBRA amp and make them all for you at a very reasonable price.

I actually forgot exactly how we did this but I know James will walk you through the process and he may ask you additional questions and measurements. I think I just initially told him my room dimensions, where in the room the amp would be located and how I was going to route the 6 hookup cables and he did the rest. The cables will arrive with the subs and amp, so you’ll just need to route the cables, cut and strip the wire on one end of some of the cables to the proper length and make the connections. I’ll also help you through the whole process through installation, configuration and completion.


"What is the reason for the (temporary?) positioning of Sub#1 and #2 facing the ceiling? Not sure I understand how/why this helps to determine woofer placement."


This is called "the Crawl Method" and it’s just a proven effective process or ’useful trick’ for properly positioning each of the 4 subs in your room. This is the exact same method I used to locate my 4 subs and it was fairly convenient and works extremely well. You’ll just be sequentially and temporarily placing each sub #1 -#4, with each sub driver facing temporarily upward to let the bass soundwaves be launched into the room freely, so you can clearly hear it and determine exactly where the bass sounds best to you as you crawl on your hands and knees in a counter-clockwise direction around the perimeter of your room beginning at the front right corner of your room.

Once you determine the exact spot that sub#1 sounds best, you then screw in the set of three spiked footers into the sub’s bottom and reposition sub#1 upright to this spot with the 10" driver facing, and about 1-2 inches away from, the wall.

You then place sub#2 (with sub#1 continuing to play) face up at your listening position and continue to crawl around the perimeter of your room, beginning at sub#1, in a counter-clockwise direction until you discover the next exact spot the bass sounds best.

Once you determine the exact spot that sub#2sounds best, you then screw in the set of three spiked footers into the sub’s bottom and reposition sub#2 upright to this spot with the 10" driver facing, and about 1-2 inches away from, the wall.

This completes the ideal and permanent positioning of your front pair of subs connected to the "A" labelled left + right speaker outputs on the sub amp/controller. The next steps are to repeat this procedure to properly position sub#3 and #4 that are connected to the "B" labelled left + right speaker outputs on the sub amp/controller.

Once all 4 subs have been properly positioned and playing, sit at your desk listening seat and verify that the bass sounds exceptionally good to you. Also walk around your office and verify the bass sounds equally good to you throughout your entire office. If it does, you’ve successfully positioned all 4 subs and this stage is completed. If it doesn’t, you’ll need to repeat this procedure from the beginning. The lesson being to take your time and be precise in determining the spot the bass sounds best to you so that each sub is properly positioned.

The next to final step is to disconnect each sub’s cabling, reroute the cables so that they’re concealed optimally and then reconnect them.

Once all cables are optimally concealed, routed and reconnected, the final step is to play the music of your choice and enjoy the heck out of your system with the newly installed near state of the art bass system!


Enjoy,

Tim