Do you think you need a subwoofer?

rauliruegas:

I thank you for this post and all of the expertise you bring. I find this fascinating and it is a ongoing part of my personal audio journey.

I've always felt that two subs are superior in reproducing appropriate sound in an audio system. The arguments you make are just spot on.

My ongoing issue now is integrating. I'm always experimenting with the controls (2) Martin Logan Depthi's). Currently, my issue is...How is the best way in which to connect?

(1) By the RCA outs from a preamp?
(2) By the speaker level inputs from an amp?

I've used for years the (1) , and find, upon thinking it through, it makes less sense. (Why not run the signal straight to your amp instead of through a whole separate circuitry?) Then the amp's character has more of a role to the subs, thus better integration. (ala = REL?)

I'm going to try (2), (next week), by using prepared cables (shotgun) that allow me to go ((after the signal comes directly from my preamp to amp)), a cable for each sub that allows each individual channel amp output to each individual subs stereo speaker level inputs, R&L per sub.

Regarding placement.. the conventional way of "in the corners", I found to be not very useful. I think this comes mostly out of "out of sight, out of mind, and a WAF". I have found that placing them close to the main speakers makes the most sense. This does interfere with most user's "other factors", as I previously stated. It does, however make the most sense in that it can integrate better with the music as it is naturally made... in stereo!

The "old school" of thought was to place them in the corners or across the room, (out of the way) since bass has been perceived as non-directional.

I've found that in looking/listening to this issue, nothing could be farther from the truth!

I could go on, but appreciate any further thoughts you may have.

Cheers,

Steve

Dear Steve, If your subwoofers have built-in amplification designed to receive signal from a line-level source, you will have a big problem driving those amplifiers from the output of your main amplifier; it won't work.  The signal voltage is much too high at the outputs of the main amplifier to drive an input designed for line level. REL specifically designs their subwoofer amplifiers to be driven by the output of a primary amplifier.  If on the other hand you are thinking of just driving the subwoofers in parallel with your main speakers, from the same single amplifier, then in part you lose one of the benefits of using a subwoofer, which is that bi-amplification removes much of the burden from the main amplifier. No free lunch.

Dear slaw: My advise through this thread that comes from my first hand experiences is that the signal from the preamp must goes directly to the subs and directly to the main amp or amps.
We want the same kind/graded of signal in both sides: subs and main speakers.

If the signal from the amp outputs goes to the subs this signal is diferent and with higher degradation.
You said : """  Then the amp's character has more of a role to the subs """, well this is not what I want it. What I want it is to have on both sides the same graded signal.

In my system I run the preamp signal directly to the subs and directly to the amps and the high-pass crossover happens inside the input circuit in my amps that are modified for that can happens. I don't use the crossover in the subs to do it or any after market crossover .

Obviously you can try what you want or what your system permits and through your listening tests  decide what  works better in your system to achieve your self music/sound priorities/targets.

Btw, which speakers do you own?

Regards and enjoy the music,
R.

I agree with the substance of Raul's advice.  In certain circumstances, one can get away with a first-order hi-pass crossover, which can therefore consist of nothing but a small value capacitor in series with the input of the amplifier that drives the main speakers, affording the least possible coloration.  Then you can add, for one example, an active lo-pass crossover to drive the woofer amplifiers, which can be much steeper in slope.

Dear friends: When we are for sure that there is nothing more to learn in any specific audio subject then suddenly we discover something else to improve the quality MUSIC/sound reproduction of our room-audio system.

I untouched my two Velodynes for years but looking for something else in my place I found out |an electrical line power regulator that I bougth so many years that I can't remember when. This same item has filters to reduce line noise and RFI/EM too, I think noise is reduced by 80-100 db.

I learned through the AHEE that it's not convenient to use that kind of power line " conditioners " with amplifiers and as a fact I never did it, I try it but in those times I can't detect improvements when in use.

Maybe I'm the only audiophile that did not do it what I explain next:

Well, I  connected both subwoofers to that device and I was totally unprepared for the HUGE and OUTSTANDING improvement in every single part of the frequency range of my whole audio system and I can tell you with all my humble " body " that the quality level I have is really excellent .

Believe me, I have no words to express it in the rigth way because for me is a totally NEW EXPERIENCE! ! !  after 40+ years to love MUSIC/sound reproduction at home.

I'm still trying to assimilate the overall improvements and I will posts on that.

In the mean time your experiences you already had are welcomed.

Regards and enjoy the music,
R.

Dear friends: First thing I can tell is that that old " warning " against line regulators with amps ( at least in my case ) is totally untrue, there is no single power limitations I can detect about.

I did it my usual whole tests wide/deep process with outstanding results.

Througth that process between other test LP tracks exist two extremely demanding bass range recordings: Telar 1812 and the RR Dafos. Both demanding not only for the speakers system or amps but everywhere from the cartridge to the room where is the audio system.

I really pushed my system with the track: Gates of Dafo's and obviously with the cannon shots in the Telarc 1812 looking for any single sign of power limitations, clipping or quality degradation at very high SPLs: 98 db at seat position with peaks over 107 dbs. It never " collapsed " in any way, everything in focus with extreme detail and resolution.

So, in my case that " warning " is a myth. Rigth now I'm waiting for other two 2.8 watts regulators to connect my monoblocks there. I have to say that I don't know what could happen when test it because my amps are fully regulated input to output. We will see.

Now and returning to the new Velodyne experiences, what am I listening through?:

- first and listening at my normal SPL this SPL " goes down ", in reality does not gone down but this is exactly what my ears and body " feels ". I know that SPL did not gone lower because I measured.

- for my " whole body " can again to feel the same SPLs than before I need to increment around 3 dbs the attenuator/volume in the Phonolinepreamp. However and after the time I just return to the past attenuator position, I don't need to do nothing about but stay there.

- in the whole bass range disappears its false bloom reproduction, false bass power feelings that is not in the recordings, notes has a never experienced clarity/resolution that today I can say are more " transparent " and with an outstanding separation in between. Yes, I'm discovering each single of my LPs ( and I say that not as the normal " cliché " some audiophiles or reviewers tell us. It's literally. ), it does not matters which one or kind of music.

- when I was feeling that I losted that " bass power "/bloom and the like what I did it was to increment the volume in the Velodynes and even that at the begining I thougth was rigth latter on I decided that was not and that I don't need to adjust the subwoofers volume but to stay as in the past.

- all those clarity, transparency and very high resolution in the bass range frequency mmade and makes that the other frequency extreme really shines as never before and yes discovering " new sounds " in the very well know recordings I have and that ow I know I really did not know so well as I imagine.

- now that both frequency extremes are THERE the mid range is too better than ever and this fact ( at least for me. ) confirm what I  was and am telling from many years now: that music at home does not belongs at the midrange frequency range but at both frequency extreme ranges that are the music frame in home reproduction.

As better both frequency extremes as better not only the mid range quality level but the overall listening experiences. Mid range depends on those frequency ranges where these frequency ranges does not depends on the mid-range.

- one part of the 1812 whole track is when we can listen the Carrillon that with its multiple bells diferent tones/harmonics and all at the same time is just imposible to identify each single of that Carrillon sounds.
Well, that was till now because I'm hearing from the very first time the real glorious of that Carrillon sounds that I never did it in any single audio system I experienced trhough my audio life ! ! !, incredible experience for say the least.



Even that some people make jokes or laugh of me ( some of you that are reading this post. ) I touted and tout, posted and post ( elsewhere ) for several years that quality level differences between different home audio systems belongs to each audio system/room DISTORTIONS LEVELS  and nothing more.

In the last times my quest was and is to make any system single change with the main target to achieve lower distortion levels and this time  ( fortunatelly. ) that " move " was and is rith on: LOWERING DISTORTION LEVELS and this fact means MORE MUSIC enjoyment.

Rigth now with that simple " move " I'm listening less to the system room/venue and more into the RECORDING. Additional what is happening/listening ( till today ) confirm not only the other changes I di it in my system in other years but what I posted in diferent audio subjects here and in other forums.

Btw, other " myth " that falls ( for me. ) is that theory that odd harmonics are so irritating to our ears and this is ( for me ) totally untrue because third or fifth bass range harmonics are pleaseant ones like the second ones and today more clear than ever and MUSIC is " harmonics ". Problem, as always, are those system distortion levels.


Yes, all pasive systems needs a pair of active subwoofers wired in true stereo fashion.

Regards and enjoy the music,
R.

Subs make the full range speakers sound better, ...also even out audible bumps in the room.

Raul....I agree as to multiple subs

A mistake: not 2.8 watts but 2.8 Kwatts regulators.

R.

Dear @stringreen : According scientific studies four subs are optimal in a home audio system.

Regards and enjoy the music,
R.

Dear friends: There are at least to things to share with you that I forgot:

- many people that own active subwoofers in their stereo audio systems speak on that thunderous bass that they don't have it before the subs in their systems and some of them speak to about that the room or diferent home items  in the room " shake/rattle " with their subs. Some like to talk about.

Well, I have not that shake/rattle or thunderous sound/reproduction in my system any more.
That kind of " events " are caused by high distortions in that frequency range but does not comes in the recordings and if some are experienced that they have an audio reproduction problem and certainly very low quality level on what are listening, it does not matters if they all are satisfied.

- the other issue I forgot is that inside my whole tests process exist the digital/CD tests that with out it any analog tests process is totally incomplete.

Testing bass range nothing can compare with the digital alternative that when with good recordings is way superior to analog and not only this but if we want to know how bass range must sound we must to listen to CDs and learn about.
I have several digital tracks that I always use trhough that whole tests evaluation's process and not only for the bass range but in this precise bass subject two of the recordings I use are: The thin red line and Gladiator ( I own " hundreds " of excellent CD that can show me what I'm looking for. ) that I know really good and what I can tell you is that the pristine, crystaline and precise definition and extremely high resolution is just: ASTONISHING.

The good " news " is that not only in the bass range but in the overall frequency ranges ! ! ! !


Thunderous bass does not comes in the recordings, it's generated on purpose by. In a home system comes for very high distortions in more than one system link and for the room interactions with.

Thunderous bass exist only in the nature through: sound on the Niagara falls or a thunder.

My take is that if we don't improve the quality level of each one bass range system/room reproduction it does not matters what we can do in the other frequency ranges our quality system levels will stay in average status.

I think all of us must have to take care more deeply on that system/room bass range reproduction !!!!

Regards and enjoy the music,
R.

Raul:
"According to scientific studies four subs are optimal in a home audio system."
     
     As a user of the 4 sub approach for the past year, I can attest to the validity of these scientific studies.  I've found the 4 sub approach has been an excellent solution for bass performance in my 23' x 16' living room.  My system is used about equally for 2-ch music and 5.1 surround HT.
     I use an Audio Kinesis Debra distributed bass array system that consists of 4 non-amplified subs (each sub is ported, has a 10" driver, weighs 67 lbs. and measures 23.75″ x 14.5″ x 10.375″) and a 950 watt class A/B amp with variable crossover and phase controls. Total price for the system is $2,990 and there is a choice of woods.  

       I was originally considering getting 2 high quality powered subs like JL, REL or Vandersteen but discovered the Debra 4 sub system while reading about the scientific studies that Raul references above. 
     These were studies by Acoustical Engineers Dr. Geddes and Dr. O'Toole that were concerned with bass wave propagation in residential and commercial spaces.  Here's a summary of their key conclusions:

Sound waves behave differently in typical rooms below and above about 200 hz.

Low frequency sound waves are so long ( a 20hz sound wave is 56.5 ft. long) that they'll bounce off room boundaries until they run out of energy.

These initial and subsequent long bass waves eventually overlap and meet which creates standing waves at various points in a room.

These standing waves result in bass peaks (perceived bass overemphasis) bass dips (perceived bass under-emphasis) and even bass cancellations (no perceived bass) at various points in a room.

They were able to mathematically predict and plot precisely where standing waves, and their corresponding peaks, nulls and cancellations, would exist in a room based on the location and number of bass sources (subs), bass frequency, room dimensions and boundary materials,

They found a relationship between the number of bass sources(subs) in a given room and the resulting number of standing waves in the room; Basically, the more subs in a given room the fewer bass standing waves are created and the better the bass.  

They note that there is, of course, a practical limit to the number of subs users will deem acceptable.

As a result and perhaps the most crucial conclusion they reached
 concerning the use of subs for residential and commercial spaces, was that the use of 4 subs in a given space resulted in the elimination of the vast majority of bass standing waves in that space. Each additional sub beyond 4 only resulted in marginal improvements.

     The DEBRA and SWARM distributed bass array systems are both based on the Geddes and O'Toole studies and conclusions and they both, unsurprisingly, utilize 4 subs.

     I honestly believe it would be almost impossible to overstate how well the DEBRA system has improved the bass performance in my room for both music and HT.  I use Magnepans for my L/C/R channels and, as many of you know, they have been notoriously difficult to integrate with subs.  The bass is solid and tuneful for music and powerful, impactful and even startling on HT.  

     With so many people using bass traps, microphones, room analysis and correction software, equalizers and digital signal processing to improve low bass performance in their rooms, I find it ironic and a touch humorous that the best solution available thus far is adding more subs.

     I don't want to leave the wrong impression, I am not wealthy and $2,990 for a sub system is expensive to me, too.  I rationalized the cost as being less than the cost of 2 high quality powered subs and that it's likely the last bass system I'll need to buy.

     The progressive and precise setup procedure is fairly elaborate and took me most of an afternoon to complete.  The subs are wired in parallel and it's recommended that 1 sub have its phase inverted.


Thanks,
  Tim   
    

Forgot to state some disclaimers:

     I have no association with, or financial interest in, anything to do with distributed bass array systems whatsoever.  I am just a very satisfied user and big fan.

Tim

Dear @noble100  : The corrupted AHEE where like it or not all audiophiles are inside teached us stay away of subwoofers in a home stereo audio system.

The audiophiles were educated in that way and even today several of them are sticky to that information.

Not only that but the name JBL was a forbidden one by that same corrupted AHEE.

Well several years ago was precisely at JBL where took one of those scientific studies on the precise convenience to install multiple subwoofers in " domestic " enviroments and its full non-refutable advantages.
These people not only make the mathematics modeling of that subs subject but they tested LIVE at its unique audio research installations/facilities.

As a part of that AHEE I never thougth or passed for my mind to install subwoofers in my home system, so I just let it gone till my " curiosity " ( many years ago too. ) to think and test " out of the box " made it that I bougth two Sweden active Audio Pro 10" subwoofers that because my very high ignorance level on the subs subject did not worked in the rigth way.

Anyway, latter on I insisted on the subject and installed my today active subwoofers that I took around one year for been totally room/system integrated with out room treatment or equalization of any kind.
In the mean time and before I sold those two Audio Pro I connected it along the Velodynes and again because my high ignorance levels the Audio Pro gone but I remember that in one of my several tests I put the Audio Pro at both sides of my seat position ( very near. ) and I could not detected its reproduction sound but was functioning onn.

Time latter and through my Velodyne's adventure I learned that the myth that over 30-40hz the bass has directionality comes down totally falls that myth because even  at 80-90 hz you can't detect it if exist good system integration.

For years in this and other threads, even in my latest posts here, I touted that the more critical an important home system frequency range is the bass one that with out a true high quality performance in that range what we are hearing is the system room with a really " poor " quality level performance even on system in the 300K prices.

I just can remember an Agoner that a few weeks ago I send him an email trying to help in some ways for his system truly shines: he owns  a very high price beautiful system with Magico speakers I think the 3 or 5 model and what I email to him was the integration of two subwoofers in his system.
I think that because that very high price on his system and because the ignorance level we all have because that corrupted AHEE he never gave me any single answer not even: thank's but NO.

That's why we audiophiles just do not grow up even that we think we are growing up ! ! !


I notice in the past your today subs kind of set up and yes I know exactly what yoi mean and enjoy and what those gentlemans really know on the overall subject. Thank's to share with all of us here.

If you note no one else but @stringreen  and you posted and I wondering if each one of aall those Agoner's ignorance levels on the bass management subject is so high that has nothing to share, comment or ask ! ! !
Always posted and post here that every single day is a learning one for me that always am open to all audio experiences from other gentlemans.

Now and ccoming back with that " thunderous " kind of sound in home audio systems:

I already said thet all comes from very high distortions that only happens in home audio systems. Let me explain my take here:

maybe some peole other than me already experienced the " fall " of a live thunder at near field from us. What can we remember about other that the very high SPL of the sound ( " fundamental " notes " ) ?: NO SINGLE VIBRATION/DISTORTIONS.

What if in the same example/experience we are at 200 m.?:

thatwe feel those vibrations/distortions/resonances all over our body. From where are coming in this example?:

it came from the enviroment that's " exited " by those fundamental/harmonic notes and that were " builded " through the " distance ".

Here the " distance " is our each one ROOM and it does not matters how we make the room treatment or equalization never really disappears and can't disappears because the bass range system ( not room. ) reproduction has " poor " quality levels.
This " poor " quality levels comes from each and all single link in the system chain. 

 Obviously than in the analog alternative is way " poor " than in the digital one and it does not matters what you think in this digital subject.

All analog lovers ( like me ) always try to have the best front end with distortions at minimum, our main concern belongs " there " and we don't take with the same " passion " the other links and especially electronics ones.

Why I mentioned electronics? because all the information is " processed " down there and we need at least that those electronics ( Phono line preamp, phono stage, line preamp or amps. ) where designed to performs from 1 hz to over 200 khz and with almost negible distortion/noise levels and that that frequency range be really flat. This must be not only our targets but the target of electronics manufacturers. Yes, additional must be a very good design and with high quality design excecution.

We can think that any kind of electronics can do it but not really. Of course thatalmost any item can have those characteristics with huge deviations on the freqency range.

Which are the precise and rigth electronic alternative we all have on " hand " to use it any time we want it?:

ONLY ONE alternative: SOLID SATE DESIGNS.

For the bass range be reproduced in precise way we need SS electronics, tube alternative is for anything you want but to handle the bass range that is where is the home system foundation.
No, hybrid designs does not meet the targets because it can't do it, is a limitation of the tube technology.

We have to remember here that what we want is not to hear/listen/enjoy the ROOM but the recording.
@lewm , you can't do nothing about and don't be angry with me again for that tube subject.

I can prove to any one what I posted here even to electronics tube designers that I respect for they shared their knowledge level on their designs. Please don't forgeret that I used for many years tube electronics and I'm not against tubes but in favor of MUSIC and what's in the recording.

There is a MoFi old recording name it: The Power and Majesty that it's in my personal evaluation tests/tracks process and is really a bass management and its meaning on almost all I posted here and this recording can tell you if our system is performing with high or poor quality level: if you know what to looking for.

Same with the several CDs tracks I use in my evaluation home  systems process: to know what to look for. 


Btw, already arrived my two 2.8 kwatts regulators. I'm with some " doubts " if it will works because my amps are fully regulated. I will connect it in my system after take a look inside the units and if I can make some tweaks down there.


Regards and enjoy the music,
R.

Raul, I agree.  For clean low bass, SS is best.  Also, I like and respect Duke Lejeune very much, and I applaud his success with AudioKinesis.  My problem when it comes to placing four subwoofers in my living room is where to place them.

But in my Beveridge system, I use a Threshold amplifier to drive my home-made transmission line woofers for all frequencies below about 100Hz, and the results are excellent. Dahlquist crossover receives the output from the preamplifier and provides the signal to the Threshold.  All solid state.

     For anyone seriously considering deploying a distributed bass array system in their system and room, I believe the thought of where to locate 4 subs is a common concern.

      It was definitely a concern of mine until I went through the rather extensive setup procedure that determines the ideal spot for each sub.  I'll describe my experience so that readers can better understand the process and how these concerns were remedied in my installation:

    My living room serves as the home for my combination  music listening and 5.1 HT system.
     It is 23 ft long and 16ft wide.  My 65" hdtv is wall mounted roughly in the center of the front 16 ft wall.  There is a Magnepan 2.7qr panel (each 6 ft tall and 2 ft wide) on each side of the tv that are both about 4 ft out from the front 16 ft wall and 1 ft in from each 23 ft side wall. There is a Magnepan CC3 center ch speaker centered above the tv that is wall mounted.    All components reside on or in a 5 ft wide by 1.5 ft tall audio cabinet located below the tv and against the 16 ft front wall.  
     The primary listening seat is centered on the rear 16 ft wall with a 7 ft sofa along the right 23 ft wall and 2 chairs along the opposite 23 ft wall.  There was not a lot of open space in this room when I began the setup procedure.
     

The setup procedure is:

Sub#1 is hooked up and placed on its back  (driver facing the ceiling) at the normal listening position. Music is played that has good and repetitive bass.

Walk around the edges of the room and determine exactly where the bass sounds best to you.

Attach the 3 spiked footers to Sub#1 and position it upright facing the nearest wall to the spot you determined the bass sounded best.

Sub#2 is hooked up and placed on its back at the primary listening position. With sub 1 & 2 playing, continue walking around the edges of your room and determine again where the bass sounds best to you.

Attach the 3 spiked footers to Sub#2 and position it upright facing the nearest wall to the spot you determined the bass sounded best.

Repeat this procedure for sub 3 & 4.

Small positioning adjustments may need to be made for each sub due to avoiding furniture and the WAF.

Once completed, final sub hook up is done in parallel:

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

Attach a single wire from the amp's speaker A's neg. output terminal and 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 parallel method on the amp's speaker B's output terminals.

I ordered single, high quality and low gauge speaker wire along with the sub system for a very reasonable price. Once the ideal locations for the subs was determined, I drilled holes in my room's floor to the crawl space below, and was able to hide the connecting wires.

     The final positioning turned out not to be an issue, with the best sounding positions actually being discreet and unobtrusive.  The 2 front subs are each located directly behind my main panel speakers and are not even visible from my primary listening position.

     The 2 rear subs are each located along each 23 ft side wall about a foot in from the rear wall.  The left wall sub is concealed from view by a leather recliner and the right wall sub is concealed behind a large end table.  My primary listening seat is between these 2 rear subs.

      I should mention I've never had my system/room analyzed using a mike and software.  From my purely subjective perspective, however, I'm confident the results would be good since I spent hours on the setup and critical listening from all six listening positions in my room. I would suggest this type of sub system as a viable alternative for anyone considering investing in one or more quality subs. The system is rated clean at 113 decibels at 20 hz. I've often heard and felt it go this deep. It feels and sounds clean and right but I can't verify the frequency, decibels or lack of distortion.

Sorry this turned out so long and windy,

  Tim     

Tim, Was this last post intended to make the rest of us feel good about the prospects of installing and positioning four subs in a listening room?  If so, it didn't work.  In my case, the listening room is our living room.  There is no video in the room at all. Apart from the physically huge audio system (Sound Lab 845PXs on the front wall and three turntables on the back wall, for example), the decor is art deco with a lot of antiques and original art works.  It's a pleasant place to be away from video, a bit smaller than your room but similar in proportions.  I would hate to have to watch out for tripping over subwoofers whilst walking around the room to change records, or when we are entertaining guests at parties.  I'll talk to Duke.

lewm:

" Tim, Was this last post intended to make the rest of us feel good about the prospects of installing and positioning four subs in a listening room?  If so, it didn't work."

Hi lewm,

     Yes,I was trying to mitigate the angst many likely experience at the thought of positioning 4 subs in their listening rooms.  My post was meant to convey that I was concerned about this, too, but that it was easier to incorporate 4 subs into my room than I initially thought.  In your case, unfortunately, you're not buying what I'm selling.

     I understand this solution may not work for everyone.  My only motivation for posting at all was to share what I know is a very effective method of attaining excellent bass response in any room that works well for both high quality 2-ch music and HT.  It is the only method I'm aware of that has this capability along with eliminating the vast majority of bass standing waves in any room which results in consistently accurate and tuneful bass throughout the entire room no matter where you are standing or sitting.

" I would hate to have to watch out for tripping over subwoofers whilst walking around the room to change records, or when we are entertaining guests at parties.  I'll talk to Duke."

     I think you would be well served by talking to Duke LeJeune at AudioKinesis.  In your case, I would suspect that you'd likely find the subs would sound best in the following positions:

The front 2 subs along the front wall behind, and discreetly hidden by,  your large Sound Labs.
One each of the back 2 subs opposite each other at some points along your side walls.

     This is only an educated guess and, of course, only you could determine if these positions would work for you.  I actually think the Debra or Swarm 4 sub system, with 4 dispersed 10" woofers, could be an ideal match for integrating well with high quality, fast electrostatic panels like sound Labs.  
     My only concern would be the possibility of the 2 side wall subs transmitting vibrations to your turntables along your rear wall.  
     I have no dog in this fight, but I really believe you would be pleasantly surprised how well a distributed bass array system could work in your room.

Please discuss with Duke.

Thanks,
  Tim

       

     

     

Dear @noble100 : For what I read from you we owns very different systems with different targets, mine is only to enjoy MUSIC and " mainly through the analog alternative that with so many troubles, limitations and disadvantages ( very well know ones. ) made it for me a huge almost titanic constant system " figth " trying to achieve the best quality level performance.
I’m not a bass’s lover but for years I learned and knew its main and critical importance to achieve that target and you know what?: I was and am not wrong in this main audio subject.

As I said I took along a complete year to achieve the precise integration of my Velodynes to my room/system with out room treatment or equalization about.

I know that with your bass array alternative i took to you 5 hours, good. I can’t discuss if your bass management room/sytem handling is better than mine for stereo MUSIC reproduction.

If you look to my virtual system, my subs position is way unorthodox for say the least: are  in front of my great ADS speakers viewing in between with the driver looking each to other Velodyne.

Btw, I have the room to have that four bass array units but before I can think on that maybe I will try what I learned from that JBL scientific studies that 3 subs are better than 2 and 4 units the " ideal " one.

I really appreciated your first time valuable contribution in this thread that try to cover perhaps the more unknowed audio main subject ever. Unknowed not only by we mere " mortal " audiophiles but for proffesional reviewer, manufacturers, designers and audio retailers/distributors.

Ignorance level is the name of the game in this case.

Regards and enjoy the music,
R.

Dear @lewm : You brougth here a serious, for its importance, bass management subject and this is the way subwoofers are designed or loading cabinet: ported/reflex/transmision line, sealed-acoustic suspension, isobarik and other that escape to my mind.
Where you decided to go with transmision line loading your subs in the Beveridge room.

The best experiences I had and have are with sealed units: isobarik Linn ( the Sara model in between. ) design, my ADS acoustic suspension/sealed and Velodyne subs.

The Linn Isobarik that I heard was really really good ( very low distortions. ) in the bass frequency range even with not to big speaker cabinets/box.
I remember heard the IMF and TDL transmision line speaker designs and like it a lot but that " laberynth/tunneling design at the end is open, yes it has lower distortion than a reflex or other vented designs and as the Isobarik with not big cabinets/boxes where my ADS to achieve its bass quality and efficiency needs a big box and very special design to go low on distortion levels.

I don’t doubt that your subs performs good but I’m sure it can’t performs better than the true bass expertes design on Velodyne and not only because I own it or because are sealed but because I made ( as I posted in this thread ) a deep investigation over the subs market and no one can compete ( even today ) with Velodyne. Remember that I’m talking here about quality bass reproduction and not bass quantity of the same.

Yes, there are more expensive units or best looking ones or that goes lower than Velodyne like JL , Rel ( only to name two of many out there. ) and others but no one can " live " not even near the Velodyne when we are talking of DIDTORTION LEVELS.

I put an example: while the JL subs performs with over 6% of THD at 20hz at 110 dbs on SPL Velodynes performs at only 0.5% ! ! thank’s that the unit is monitoring the woofer excursion over 16k times each second.

I know for sure that after my Velodynes be connected through those electrical regulators that DISTORTION LEVELS goes even lower and this is the main subject here: QUALITY LEVEL.


Btw, last nigth I really pushed my Velodynes through recordings that are not specific because its bass range stand alone but because use synthetizers between other instruments including full symphonic orchestras.
What I want to achieve is if at some SPL I can have in my listening room or outside it some kind of rattle in diferent things that are in that living room.

So, I push it at very high SPL that I measured at my seat position as : 105 db with peaks over 112 dbs ( even I " closed " my ears at this volume. ) and no single rattle, glass resonances or rare vibations or that something collapsed not even the soundstage and focus. !!!!

That is unbeliable for any one ( nas I said: distortions gone really lower ! ! !. ) but me that experienced it and this tell me that I’m in a new audio era/century/reborn.

@lewm till you can achieve that experience in your system you can’t know how much you ( everyone. ) are losting of MUSIC as I did it for more than 40+ audio years mand that audio losted years was thanks to that AHEE.




Regards and enjoy the music,
R.

Raul,

     I'm sorry but I'm having a hard time reading and making sense of your posts.  I think I'm getting the general idea but I'm not certain.

Thanks,
   Tim

Dear @noble100 : Sorry, my english is to bad but as you said I think you have the whole " idea ".

Regards and enjoy the music,
R.

Raul,

     I think I'm getting the gist (main idea) of what you are saying but please correct me if I seem not to understand.

     You are making the effort to communicate in writing in English as a 2nd language which I understand must be difficult.  The least I can do is make the effort and take the time to understand your meaning as best as I can.

     I do not want you to stop posting, since practice is likely only going to improve your English written skills.

Thank you, 
  Tim

       .  

Dear friends: I already connected my main monoblok amps to each one electrical power regulators I bougth.

I decided to buy it after I discovery the huge ( no words to explain it. ) improvement inj the quality level performance of my Velodyne’s.
I had several doubts that really could be a real improvement and not only a diferent kind of sound because my 20.6s are fully regulated input to output.

So why external electrical power regulators for?, I have no precise explanation why I bougth it even the amps kind of design other that " curiosity " and after connected and gave a deep listening I would like to know what is happening. Let me explain it for you can give an opinion or share similar experiences:


for years my amps were connected directly from the inside electrical power amp input through my 30A electrical dedicated line power box, no single connector in between. When I did it the improvement was inmediatly, connectors even here and even top ones degrade the quality system level performance. Why?, I don’t know for sure.

Before the amps wre connected to the electrical line regulators I made it some usually ( for me. ) tweaks: changed its stock power cable by passing all connectors all from inside input to the line power box.

What happened when I switch-on the system and started to listen through my personal test evaluation process?:

something unexpected for me and it happened and still does just from the very first MUSIC " note " in the LP tracks and CD ones:

first thing I was aware is that my system already very low noise gone not even lower but now exist NO noise floor level. I just can’t detect it.

That " simple " fact makes several things in my MUSIC everyday listening sessions. When you hear my today system performance, believe or not, you can think you are enjoying MUSIC in " wonderland ". Like me you can’t believe it till you can have this kind of unique experiences.

It’s not only that no-noise floor characteristic but if with the experiences I shared here with my subwoofers the ROOM interaction goes down at this moment/time that same ROOM just gone. I can’t explain it in other way.

I’m feel like a Symphonic Director’s Orchestra at his stage position whre exist only HE and the near field sources/instruments ! ! ! !

That sesation can be understand it only if you been listening in a true Music Hall at that position that as I posted somewhere in this forum I been there twice.

In that listening position there is no ROOM/venue but direct MUSIC and t’s almost here where the recording microphones are seated.

That’s why I said : listen to the recording and not your ROOM that’s what you are doing rigth now in the same way I did it.

Room treatments?, the best room is NO ROOM.

I think I already posted here: for me the audio/MUSIC hobby just begin with and I’m discovering so many things that I really can’t assimilated and I can’t be sure about explanations yet.

One thing is sure: I have to re-set the whole tonearm/cartridge set up that I was thinking was fine when was wrong ! !, go figure.
This time the word ACCURACY have a true and real meaning on that subject and this time more than ever the MINT LP protractor has its real necessity.
Now there is no " land " where any minimum mistake can hide it and not only in the whole system performance but today I’m aware of recording errors and the already analog limitations goes higher too or at least more real than ever and my many years touted digital alternative shows its several advantages at a higher levels.

How can be that my so hard work on system set up been plain wrong for so many years?
I think because the ignorance levels we have that impede to grow up and stay sticky with what we thougth is " great " when in reality is not that way.

WHAT A KIND OF AUDIO LESSONS and I’m fortunate to discovery all those and many things to come trhough my listening times.

Yes, I only want to listen MUSIC as never before and we will see what I can share over time.


Regards and enjoy the music,
R.

Hi Raul,

     I'm glad that you're very pleased with your system's performance after you added the electrical line regulators.  I'm not exactly sure what regulators these are but I'm very interested in them since reading about your great results.

     After re-reading your posts, I found that we agree on several opinions:

1. The importance of a low noise floor not only in presenting music recordings accurately, with more easily heard details and enjoyably but also because it enables the affects of small changes ('tweaks' such as power regulators, turntable tone arm/cartridge/VTL setting changes, power cord/speaker cable/interconnect cable changes, etc.) to be more clearly heard due to this increased accuracy, neutrality and audible details.  

       You achieved accuracy, neutrality and a low noise floor via component selection and your regulators.  I achieved this mainly through a change from a class A/B amp to a pair of class D mono-blocks (Aragon 4004 to D-Sonic M3-600-M).  I believe my mono-blocks have built in regulators that conditions the electricity prior to introduction into the amp's input stage.

     We use slightly different methods of regulating the home electricity going into our systems for the same purpose of eliminating artifacts and lowering the noise floor. 
 
2. The importance of good bass response in not only extending the frequency response lower for a more realistic experience but also because of the affect that good bass response has on improving a system's mid-range/treble performance and resultant improvement in a system's ability to create a more solid and stable sound stage illusion.

      You have achieved good low bass in your system by fine tuning the positioning of your 2 Velodyne subs over a period of years and I achieved it through the use of the 4 sub Audio Kinesis distributed bass array system following their progressive setup procedure.  

     The important thing is that,  through slightly different means, we've both achieved good  bass response in our rooms.
     The less important question of which method performs best, will have to remain an open question
     I think we both agree that the most important thing is that we're both happy with our systems and enjoying our music.

Thanks,
  Tim  

 
 

Dear @noble100 : """  1. The importance of a low noise floor not only in presenting music recordings accurately, with more easily heard details and enjoyably but also because it enables the affects of small changes .... to be more clearly heard due to this increased accuracy, neutrality and audible details.  ""

I don't know other audiophiles but me when read something about audio room/system noise floor never had the true significant meaning like this time like these " today " unique experiences.

It's obvious that all those twecks we did and do it with our each one system has as a target to improve its quality level performance and even if we do not took or take its importance every time we improve ( in any way. ) the quality level of the room/system what we did it was and is lowering distortion levels that improve /lower the room/system NOISE FLOOR but this time is the very first time I'm really aware of this system/room characteristic and its crucial/critical importance to enjoy at maximum the listen recording experiences.
For me the improved diferences were " an order of magnitud ": outstanding!

That is a real no-return path/road and a must to achieve in any audio room/system.

Perhaps, many of us think we already have it but perhaps as me we don't have it.



"""  2. The importance of good bass response in not only extending the frequency response lower for a more realistic experience but also because of the affect that good bass response has on improving a system's mid-range/treble performance .... """


as I posted the bass range is the foundation of MUSIC and to enjoy in our audio room/system we need first that that audio system be a full range one, not from 28-30hz and up but true full range ( even a little lower than 20 hz. ). With out that " full range " characteristics we just can't listen adequatly the MUSIC/LP/CD overall experience. This is a necessity not something that we could wish and it does not matters what kind or price level has the audio system: if it does not has the " full range " factor then it be short of and the MUSIC experiences are totally incomplete for say the least.

As you said the importance of good bass response, (I can add: good FULL bass response, is not precisely for extended bass frequency only but for the midrange/treble really shines too. I explain it in this thread here:

https://forum.audiogon.com/discussions/do-you-think-you-need-a-subwoofer/post?postid=310058#310058  

yes LIGTHS ON, we left the darkness! We must try it and please forgeret about that: " I have no space/land/room " for two subwoofers because this is only one way to say: " I don't do it  because I don't think is an improvement in my already good quality level performance I have " .
That kind of way of thinking only makes we are loosing the real MUSIC meaning enjoy.

I can tell you and all audiophiles that no single tweack kind of changes we can do in our room/system can gives us the full rewards as the rigth bass management achievement along that lower NOISE FLOOR.


Btw, was so impressive what the electrical line regulators did it in my audio room/system that I tested through my bedroom 4K TV with outstanding  results too. It's like instead of 4K resolution the TV pictures/images been " 16K ( that does not exist. ). Of course I already bougth a 1K regulator that's the one rigth now I'm using with.

Regards and enioy the music,
R.

Dear friends: STOP THE PRESS and read before:

all my audio system links including the speakers/subwoofers ( even the speaker's crossover inductors. ) are wired or rewired internally with silver wire but my Phonolinepreamp because has no single internal wire through its design, the system interconnect cables are from silver too.

Well, two days ago that I opened one of my elctrical line regulators/conditioners I have to change two short internal wires/cables ( 15cm. ) and the only ones at hand were KCAG silver by Kimber Kable.

After that I just seated to listen MUSIC and " something " happened that has no explanation and that was totally unexpected because the cable I changed was a necessity more than to achieve a real improvement but it happens ! ! ! ! 

Then and due that I still have some KCAG cables I use it instead my after market power cords in my Phonolinepreamp and fenomenal THINGS followed happening ! ! ! ! 

Was so outstanding that I already ordered more KCAG to change all my system power cables.

The improvements were to many that can resume in two main ones and what these two represnet on the overall quality performance level in any audio system:

- NOISE FLOOR REDUCTION and

_  LESS ROOM INTERACTION with higher system electronic/speaker headroom levels.

Astonishing, is it?  ! ! !


Lesson: we need SILVER wires in the electrical power system cables.


Regards and enjoy the music,
R.

Dear friends: First time I used KK 4TC/8TC cooper braided speaker cable for electrical line power cables in my electronics and especially with amplifiers I use it in shot gun configuration, this is that each single 8TC cable for the positive and other complete 8TC for N.

This is very important issue and is how I'm wiring with pure SILVER today all the system electrical line power cables everywhere.

Yes, it's a little expensive but IMHO nothing can wive us so outstanding rewards as this system tweack along the line regulators.

SILVER is the name of the game in this particular audio subject.

Regards and enjoy the music,
R.

I thought readers of this thread might want to read a professional review of the 4 sub distributed bass array system I discussed previously:

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

     This is actually about Duke Lejeune’s Swarm system but it’s virtually identical to James Romeyn’s Debra system that I own; exact same 4 ohm subs with 10" drivers, 1,000 watt class A/B ampifier along with the exact same setup procedure and wiring method.

Again, a reasonably priced system that delivers excellent bass in any room for both music and ht without the need for any room treatments and without any room analysis/room correction software or equipment. Yes, you do need to accommodate 4 (1 sq. ft. footprint and 2 ft. tall) subs in your room but it delivers the best bass response I’ve yet experienced in my room. I just want to let everyone know how well these systems work.

Thanks,
Tim

With a Mini DSP 2x4 you can control up to 4 subs on line level. Food for thought . I am going to try it soon

I use Vandersteen 5A speakers.  They have built-in subs that are driven from their own amps...my main stereo amp drives the mids/highs.  This frees up the amp from the power hungry subs and permits it to just loaf with smile.  Two subs are better than one - they better fill in the lower reflections of the room

Dear @noble100 :  """  You achieved accuracy, neutrality and a low noise floor via component selection and your regulators.  I achieved this mainly through a change from a class A/B amp to a pair of class D mono-blocks.  I believe my mono-blocks have built in regulators that conditions the electricity prior to introduction into the amp's input stage. """

well, my ML monoblocks are fully regulated input to output and I can hear the improvement of my today regulated electrical lines. So, you could try/test it.


"""  You have achieved good low bass in your system by fine tuning the positioning of your 2 Velodyne subs over a period of years and I achieved it through the use of the 4 sub Audio Kinesis distributed bass array system following their progressive setup procedure.  

     The important thing is that, through slightly different means, we've both achieved good  bass response in our rooms. """


When I bougth my Velodynesmy target was to have a thigt er and more precise low bass end with lower overhang than my main speakers but over the time and even that I have it my personal finding in those times was that existed not an additional benefit in the system subs integration but a main benefits even more important than the low bass stand alone subject and that main benefit/target was and is explained in that link that I post here again. This is for me my real discovery because in those times I was unaware of the JBL or Geedes multiple subs white papers/options and certainly not what you posted here and are using at your place:

https://forum.audiogon.com/discussions/do-you-think-you-need-a-subwoofer/post?postid=310058#310058 


Years latter I have a dialogue/discussion with Mr. Geedes in other forum from where I was banned ( people are not prepared for me. ).
Well, I shared that link experiences but he did not cares about, he only talks on for what him was the main target: low bass.

I think that to have a reall good  system bass managemnt through subs is an " additional " benefit to what I'm talking about.

Obviously that today things changed for the better till not only that noise floor or accuracy but the must important issue for me is that when BASS System MANAGEMENT is rigth then there is no need of almost any room treatment because ROOM DISAPPEARS ! ! !  and this is the AMAZING and new experience for every one ( like you. ) that experiment/try with.

As you can see almost no one of the regulars in this forum posted in the last weeks in this thread and this fact speaks for it self.

I can remember audiophiles excuses to not try the subs experiences, everyt kind of excuses and I remember very clear this one with Avalon speakers ( I remember this same kind of excuse with other audiophiles and diferent speakers. ):

" I don't want to use the high pass crossover my Avalons in a frequency range where its shines. """, but something like this was the same with a Magico owner that has problems with these speakers. people just don't want to grow up and prefers stay in his " confort chair ". Even my cvlose friend Guillermo who owns top Soundlabs gave me similar answer years ago but here today are using a pair of subs with that great Soundlabs he owns!.

Regards and enjoy the music,
R.

Dear @noble100 :  I was trying to find out information of what tipycal level of THD has a bass/subwoofers configuration as the one you have but it does not exist something about.

Do you have that information or a link with?

regards and enjoy the music,
R.

Dear @noble100 : I think that that information does not exist for a specific room/system.

In the old JBL papers the main subject is a room evn bass: no problems by standing waves, almost flat bass frequency range and the like but never gave any THD information and this for me is a critical issue.

Room does not disappears only because bass management is rigth but only is the bass and overall syatem distortion in the room is really low.

That's why I ask about.

It's really " curious " that when we talk about manufacturers of subwoofers for home stereo systems no one gives the THD of their models and I know this because I call/email almost all of them and no one return with that information.

Velodyne 15/18 has only 0.5% THD at 20hz at 120db. This sole figure is just IMPRESSIVE by any standard.

By comparison the touted JL Audio subs that never gaves that THD figure were reviewed by ST and Atkinson gaves it at 6%. Yes, it's a very good looking unit but nothing that can not even the Velodyne but is far away from it. Sorry for the owners that have that very high distortion levels in the main home system audio bass range.
Now, what happens with JLA is not only them almost all subs in the market but Velodyne has problems there.

THD, between other things, is one spec critical when we are buying subs.

Regards and enjoy the music,
R.

Hi Raul,

     You asked: " I was trying to find out information of what typical level of THD has a bass/subwoofers configuration as the one you have but it does not exist something about.   I think that that information does not exist for a specific room/system.

     I checked the James Romeyn Debra, Audio Kinesis Swarm along with google searches sites and I think you're correct, there is no info regarding THD on distributed bass array systems.

     I did find an interview with Duke Lejeune, in the Stereo Times

     http://www.stereotimes.com/comm081710.shtml

     He mentions that when he started designing speakers his goal was low distortion and accuracy.  But, when he was finally close to meeting  these goals, the speakers did not sound good at all.   He was talking about his full range speakers but this may apply to his Swarm system as well.
      I think you may be more concerned with THD than I am because I honestly have never perceived any negative qualities that I'd attribute to distortion on music or HT.    
     

Dear @noble100 and friends: I’m always concerned on something that’s happening and where there is no single information.

It’s weird that not only in information coming from the sites you linked and from the JBL information all those gentlemans speaks about even bass response but no one of them " touch " nothing in reference at distortions levels not only THD or IMD but any kind of distortion.

That’s why I always try to think " out of the box " and asking me for " something "...

Speaking of " OTB " I just made it another fasinating move and here it’s a totally new discovery for the better:

as many of you and through the years I was testing different power line fuses at the electronic inputs in all my electronic system items where I found out that better quality fuses just means better quality performance in this regards the best I found out are the ones coming from Synergistic Research: Quantum Red and Black.

What did I?, now that I have my dedicated power line " bullet proof " fully regulated, with surge protection, RF/EMI filters I thought:
What if I by-pass all those fuses ( 14 in my system. ) due that I don’t need any more because the whole system is protected in that fuse task regards?

Well I did it and was and is jus " genial ": quality system sound performance level improved so: The Best Fuse Is Not Fuse At All ! ! !

What a discovery ! just great one.

All that improved system noise floor, bass range, room " disappears " that I achieved with my last discoveries posted in this tread only improved again when I was thinking that nothing could help to improve it. Fortunatelly I was wrong with this last sentence.

Rigth now there are no fuses in: my subwoofers, amplifiers, CD player, TT power supply and phonolinepreamp and the digital an analog performance is better than ever with an unbeatable high resolution where we can aware of the digital/analog source errors and advantages of each alternative in between. Btw, analog just hands down digital alternative.

I think that all of you that have a precise proved regulated/surge protection power line have to test it and I’m sure you will enhance your system enjoying listening sessions.

Regards and enjoy de MUSIC not distortions,
R.

enginedr1960,


Congratulations, I'm glad the distributed bass array system works as well in your room as it does in mine.  I'm not really surprised since this method has been proven to work in numerous rooms no matter the size or shape.

But, if you don't mind, could you give us a few details such as:

Are the 2 additional subs you added the same brand and model as your original 2 subs?
Are your subs self amplified or passive (driven by separate amp(s))?
What method did you use to locate the subs in your room?
Where did you windup locating the 4 subs in your room?
Do you use your system for 2-ch music, HT or both?

     I think I've stated my system is used for both 2 ch music and HT and, just as you stated, "the whole system just sounds right" for both.  I still find I'm amazed how well the distributed bass array system works and with absolutely no room treatments, microphones, software programs or equalizers required.
     I know the distributed bass array system is scientifically based and has been empirically verified by numerous independent acoustic engineers and users but I'm still amazed how well it works.  Taut, powerful and textured bass that integrates seamlessly and just sounds life-like and right.

Thanks,
   Tim

I've resisted using a subwoofer (or really a woofer based system, not really a "subwoofer" per se) with my Sound Lab 845PX speakers for several years.  The reasons for my recalcitrance are as follows:
(1) I've never met an electronic crossover that did not color the sound in some objectionable and noticeable way.
(2) I am getting tremendous low bass response from my 845PXs with no added woofer (but see below).
(3) I ascribe to the idea that one-way systems are a virtue; I have revised the electronics in my 845PXs to eliminate the filtering that precedes the two audio step-up transformers. (This is another long story not suitable to this thread.)  There is no crossover in my system anywhere and only one 0.1uF capacitor in the signal path, from the line level input of the preamplifier to the speakers. 
(4) I envisioned that adding a woofer system would require introducing at least two large-ish and probably ugly cabinets into our living room, and I am or was loathe to do that. Esthetics matter to me.

However, the price I pay for this policy is in fact that I have too much bass.  I do perceive suboptimal resolution and definition at the extreme lowest frequencies, where there is not so much a "peak" but a gradual rise in speaker output.  I use Tube Traps behind each SL panel to ameliorate this problem, but it is not a perfect solution. I believe this is because the SL speakers rise in impedance as frequency goes down.  (I've measured this.) Since I use OTL tube amplifiers, this results in a broad rise in speaker output, inversely related to frequency. (The OTLs love high impedance.)  Lately, I perceive there are ways to overcome my reservations about electronic crossovers, either by using only a capacitor at the amplifier input, to roll off the 845PXs at low frequency, or by using any of a very few electronic crossovers that may be acceptable to me.  In addition, one of you guys pointed out that a pair of woofers could be placed behind the panels, out of sight, and that the cabinets need not be huge.

Over the years, I have made this system better and better.  Now I think the only thing left is to take a shot at adding a woofer supplement.  Duke LeJeune probably knows more about supplementing SL speakers than anyone, and I intend to consult with Duke on the best course of action.

To clear up my system and crossover implementation I use a cap in the signal input to my VTL100 tube mono blocks to make a high pass @ 50 hrz . and use the Mini DSP 2x4 as the sub only crossover that I can adjust on the fly . The extra subs serve as active room treatment

lewn,

   As you are well aware, the Sound Lab 845Pxs are excellent speakers that are capable of going fairly deep (26 hz).  However,  I believe a distributive bass arrray (DBA) would be a very good solution in your system for several reasons:

1.  The bass produced by a DBA, using 4 10" driver subs, will be seamlessly integrated into the sound coming from your sound Labs; capable of being as quick and detailed as the Sound Labs or deeper and more powerful depending on the source content.  

2.  Using a DBA will relieve your OTL amps and the Sound Labs from reproducing the more demanding lowest frequencies., the supplied separate class A/B amp would be powering the bass (if you go with the Audio Kinesis Swarm or Debra DBA) or the internal class D amps on the mini-subs would be powering the bass (if you go with the Rel q201e subs that enginedr1960 uses).  You could then turn down the bass level to taste on the Sound Labs.  I think the result would be even better performance from the Sound Labs (especially in increased dynamics) since your OTL amp would mainly be powering the mid-range and treble with bass level powering reduced by the amount you determine sounds best.

3.  Using a DBA as described above will significantly reduce the amount of crossover circuitry in your system's signal path.  There would only be crossover circuitry in the bass level that is built into both the Audio Kinesis separate amp or each individual powered sub.  
      You would customize the bass to your preference by a combination of reducing the bass output level on your Sound Labs and adjusting the crossover frequency and volume setting on the Audio Kinesis DBA separate amp or each individual powered mini sub.  A bit cumbersome but it would provide great flexibility in dialing in the bass to your exact preferences.

4  Room aesthetics would be minimally affected. I replied to you in an earlier post about this.  
     Basically, I described how my 2 front subs are hidden behind my 2ft wide panel speakers and the other 2 (each along a side wall near a back wall) are partially hidden by a leather chair and an oversized end table.
      My room is 23ft x 16ft with an 8ft ceiling and I barely notice them.  I think your room may be even larger.  Your panels are also even wider at 3ft so, as long as you determined through the setup process the subs sound best at those positions, they would be completely hidden from view.  That just leaves the rear 2 subs that need to be creatively hidden.


   Just my thoughts but I really believe a DBA would be a great sonic match with your Sound Labs.

Tim
   

enginedr1960,

If someone is not buying a complete DBA (distributed bass array) such as the Audio Kinesis Debra or Swarm systems, I think the Rel q201e mini subs might be the ideal sub to use in a custom 4 sub DBA as you assembled. These subs are similar to the Debra and Swarm subs; compact and they utilize 10" drivers. Great choice.

I just have a few suggestions for you and your custom DBA:

1. The DSPeaker Antimode 2.0 and Mini DSP 2 x 4 may have been good tools when utilizing 2 subs but I really don’t believe they’re necessary in a 4 sub DBA. You may want to use the Antimode to verify after the first 2 subs are positioned optimally by ear but I doubt any signal processing will offer any sonic improvements. I don’t think the 2 x 4 will be needed either. I’m certain there is no need for microphones, analyzing or correcting software, equalizers or room treatments when the proper progressive setup procedure is followed.

2. The proper progressive setup procedure is the following:

Sub#1 is hooked up and placed on its back (driver facing the ceiling) at the normal listening position. Music is played that has good and repetitive bass.

Walk around the edges of the room and determine exactly where the bass sounds best to you.

Attach the 3 spiked footers to Sub#1 and position it upright facing the nearest wall to the spot you determined the bass sounded best.

Sub#2 is hooked up and placed on its back at the primary listening position. With sub 1 & 2 playing, continue walking around the edges of your room and determine again where the bass sounds best to you.

Attach the 3 spiked footers to Sub#2 and position it upright facing the nearest wall to the spot you determined the bass sounded best.

Repeat this procedure for sub 3 & 4.

Small positioning adjustments may need to be made for each sub due to avoiding furniture and the WAF.

Once completed, final sub hook up is done in parallel (which you can ignore since you’re using self powered Rel subs):

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

Attach a single wire from the amp’s speaker A’s neg. output terminal and 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 parallel method on the amp’s speaker B’s output terminals.

3. Your Rel q201e subs are front firing and I assume you have them pointed out into the room. You may want to try the Debra and Swarm method of pointing each driver directly at the wall no more than an inch away from the wall. I’m not sure this will improve your system’s bass performance but thought you should be aware of how it’s done with the Debra and Swarm systems and determine for yourself which positioning sounds best to you.

4. As you’re probably already aware, selecting the proper cutoff frequency is very important. My main speakers are Magnepans that only have good and accurate bass response down to just below 40 hz. I run my main spkrs full range and use a 40 hz cutoff frequency For 2 ch music and usually 40-60 hz for HT. My center channel and rear surrounds don’t go much deeper than about 8o hz. so this creates a frequency response hole from 40-60 hz up to about 80 hz bass for HT. When I’ve set the cutoff freq. to 80 hz for HT, however, the bass sounds too boomy to me so I prefer to set it at 40-50 hz and the bass response sounds much better to me even though I know there’s a lack of bass response in the 40/50 to 80 hz range; I find I really don’t miss these frequencies.

Your Ohm Walsh 2.2000 monitors go a bit deeper to about 32 hz. so you may need to find the cutoff freq. that sounds best to you. You may also want to try filtering out frequencies below a certain hz(and correspondingly raising the cutoff freq. the subs operate at) to see if your monitors sound even better when their bass duties are reduced.

5. The last suggestion I have (is that applause I hear?) is to sequentially reverse the polarity on 1 of your subs at a time while listening to the same content with good repetitive bass. The idea is that bass response will sound its best with one of the 4 subs running in reverse polarity. The theory is that system bass will sound noticeably better with one specific sub running in reversed polarity. The tricky part is determining which of the 4 subs this is. I cannot verify this improves performance since I was too lazy, and my system bass sounded so good as is, I’ve still not gone through this process.

Hope this info and advice helped,
Tim

Hi enginedr1960,

      I understand the frustrations and compromises involved with the infamous and insideous WAF.
       I followed the  elaborate progressive sub setup procedure  rather strictly.  I took my time determining  exactly where the bass sounded best and clearly noticed the bass sounded the most natural to me located at least a about a foot or more away from room corners; the corner positions definitely reinforced  the bass response, causing bass peaks and were sub position sites I knew should be avoided.
      My goal was to find the precise locations in my room where the bass just sounded natural and right and I avoided all locations where the bass was over or under emphasized.  I think this is the reason that none of my 4 subs are located at one of my room's 4 corners.

    However, I understand your significant other may prefer the subs be tucked way in the corners of your room, the exact locations that are most likely to result in the presence of bass peaks at certain spots in your room where bass response is obviously exaggerated. 

    Just a word of warning, none of the subs should be placed squarely in a corner unless you determine that is where it sounds best, which is unlikely.  If you must place a sub near a corner,  it's best to position it at least a few inches away from the corner's center along one wall or the other.

   It seems like you've become too accustomed to using your DSPeak and 2 x 4 to even consider not using them.   I still believe there's no need for these tools, or even your Bent Audio volume control,  in a properly setup DBA system.  However, I may not completely understand why you consider these products so indispensable.

Thanks,
 Tim

Tim (Noble100)
We are on the same page.  However, I would be doing it for the gain in bass definition and overall frequency balance, more than to relieve my primary amplifiers of any stress.  The 845PX's normally use a 6db/octave passive crossover in front of two different audio step-up transformers that receive, respectively, bass and treble frequencies after the x-over.  This configuration, however, creates a nasty impedance dip at mid-frequencies, in addition to sucking energy across the resistor used in the hi-pass filter.  2-3 years ago, I replaced the treble transformer with a very high quality full range transformer, which enable me to ditch the RC network that creates the hi-pass; I still use an inductor in front of the original SL bass transformer, albeit I replaced the OEM inductor with an 12-ga air core type.  This mod hugely improved the efficiency of the speaker; I daresay it could be driven by less than 50W to very loud sound pressures.  My OTLs can do about 100W, and they are loafing at all times. It also dramatically improved dynamics.  I measured impedance v frequency across the audio range, after the mod, and I see 20 ohms or greater from about 100 Hz to 5kHz. Below 100 Hz, impedance is rising.  Above 5kHz, it falls to about 6-8 ohms at 10 Khz. This is an ideal match for an OTL.

I did mention that someone here had pointed out that two of the 4 woofers could go behind the panels.  Sorry for not remembering to credit you with that insight.  I've known Duke for a long time; I bought my 845s from him.  I will give him a call soon. On his website today, I do see the Swarm, but I don't see the Debra system.  I'll look again.

Hi lewm,

     I already knew the 845s are one of the most efficient Sound Labs ever made (about 89 db).  It sounds like your mods made them even more efficient and a good match with your OTL tube amp.

     I was just listing all the benefits I thought going to a DBA would have in your situation.  I now understand you don't really need to decrease the demand on your OTL.  You're more interested in a DBA to get a more full-range frequency balance and increase bass definition.

     I can confirm that a Debra or Swarm DBA will give your system high quality bass that is capable of blending seamlessly with your Sound Labs while it's also able to reproduce deep,powerful and impactful bass when the content calls for it.

     Just to clarify, Duke sells the Audio Kinesis Swarm and James Romeyn Audio LLC.  in Utah sells the Debra system. Here's a link to the Debra system:
http://jamesromeyn.com/old-pages/home-audio-gear/dsa-1-0-distributed-subwoofer-array-5-pieces-4k-usd...


 They're both basically the same 4 sub DBA, with small differences mainly in the subs' construction.  James licenses the rights to sell it from his friend Duke.   They both come with the same 1,000 watt class A/B sub amp, are both rated accurate down to 20 hertz, about the same system price and share the exact same setup procedure.  Either system will deliver excellent bass response that is very evenly dispersed due to the significant reduction in bass standing waves in your room.

     I didn,t know you bought your Sound Labs from Duke.  He'll be able to give you good advice on how well the Swarm would integrate with your 845s.

  Good idea to give him a call,

                Tim   

     

Dear @enginedr1960: I think that you can have even better results if your monitor hi-pass changes from 50hz to 80hz. You can do it listen it and decide about. It's only an alternative to test it.


regards and enjoy the music,
R.

Thanks  R I have been thinking that myself . I need to change the value of the amps signal line caps . I will give it a try .

Thanks, Noble. I did find the Romeyn website for the Debra, by searching on "Audiokinesis Debra", oddly. As you note, they are similar in price and very similar in composition.  So this begs the question, why are two different and so similar products co-existing?  Do you have a feel for the audible differences between the two?  And, a question I will address to Duke as well, does the set-up provide for a hi-pass filter to feed the amplifier that is driving the main speakers?

Hi Tim great thing about this hobby is there are many ways to achieve great sound . I chose my components very carefully based on my preferences . I do my research and know how to read in between the lines . I am a engine builder by trade I take the same approach in building a audio system as a high performance engine . I apply the system to the room . The Bent passive Dave Slagle autoformer volume control is a great component . The volume control in most audio systems is the weak link . Do some web research on transformer and autoformer volume controls . I have a great sounding system at the lower volume range then all the others I have heard . Remember you cant fix it unless you know how it works !