My experience adding subwoofers to 2 channel


My Kappa 9 speakers are rated to 29hz and they sound pretty good in my 18x24 room...powered by McIntosh mc1.25 amps...l was looking for another layer of bass to enhance the sound..my first experiment l took my SVS pb16 ultras from my theater room and tried them first...it sounded terrible,didn't blend well..couldn't hear a difference until you turned in up then it rattled the room apart........my final experiment worked..l used 4 Velodyne minivee subwoofers(1000 watt rms class D sealed 8 in.) and after hours of calibration l hit it......lve got the bass response that exeeded my expectations. ....l should have done this along time ago....can anybody tell me of another subwoofer that may work even better?
Previewvinnydabully
Sadly, what I'm reading here is not unique.It's not the sub, it's the calibration and how little most consumers know about how to do it well.


Your best bet is a sub with room correction built in, or a pre/integrated with it like the new Anthem line.


I make my own speakers, and from my perspective, integrating a sub is practically crossover building.

Also, talk to GIK Acoustics. Great advice and great products. Their soffit traps and bass traps can really help.
It is like crossover building makes total sense. If l ran a test tone sweep through the mains with subs off the bass started falling off pretty steady below 50hz. Now it stays flat down to 25hz. It's the closest sound to a real drumset that ive had so far..l wasn't going for the deepest bass possible. ..l like alot of energy around the 50 to 30hz. range for my favorite music....The system didn't need a whole lot, but when the subs are perfectly blended with the mains it becomes a whole different beast.l should have done this years ago...l bought all four subwoofers used for 1000.00....l may consider some new Audiophile grade subwoofers down the road..such as Rel.or possibly some sealed SVS models....
Multiple subs is the way to go. The more the better. Once you get to where you are now though (4) then yes better quality subs will be better. Also having them spread around the room, basically one per wall but asymmetrically not just one in each corner, helps to get smoother flatter response. Where are yours now? 
Hello vinnydabully,

     What you apparently discovered by accident is called a 4-sub distributed bass array system.  The key is having 4 subs and I've been using one for the last 4 yrs with large Magnepan panels.  The Audio Kinesis Swarm and Debra are complete 4-sub DBA systems that sell for about $2,800, and the 4-sub DBA concept works like a charm.  Here's an Absolute Sound review of the Swarm:

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

    As you've discovered, you can create your own custom DBA using whatever 4 subs you prefer.  The concept is based on scientific research done by Dr. Earl Geddes and Dr. Floyd Toole. 

    I and others have started threads on how well this concept works:

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

     You can google 'distributed bass array', 'geddes' or 'toole' if you'd like to read more.


Tim   
4 JL Audio Fathom V2.  That should scare your neighbors to death.
After reading the threads here and doing further research,I added a second sub last week.I was so pleased with the improvement I've got two more  on the way to complete my 'swarm '.
My subs are located behind my main speakers in the front corners...behind some silk plants....you cant see them ...makes it very "steathy"and cool......l will try all four corners soon....my McIntosh C52 pre amp has switchable outputs for tri-amping so l can turn the subs on in groups of two or turn them off from the preamp front panel...very convenient. ....the "swarm configuration " will be the next phase ......the receptacles and audio cables are going to take some planning. ...thanks guys for the cool advise! 
Its amazing when it comes to bass how much better more is than few. With subs unlike the L/R stereo pair the subs can be completely different and located almost at random and yet still work just fine. So they can be "cobbled together" buying whatever you can whenever you can add and still wind up with excellent results. This might even be the best way to go, because of all the flexibility being able to adjust crossover and level of each individual sub. If you can afford a better sub great, but if you can only afford a cheaper one that's great too because more is always better.
Well Vin, you've gone and done it. Could it be that you filtered through all the pontification of endless subwoofer suggestions and found you're own suitable success? It certainly sounds that way!

I'll apologize in advance for one last thought. If you find yourself beginning to differentiate between your mains and the subs then I suggest considering Eric's advise.

Keep your eyes peeled for a small used Velodyne DD Plus. You can slave all the Minivees off the DD. The Velodyne Room Optimization program goes much further than Anthem, JL Audio, and even Magico. What took you hours can be accomplished in minutes. You'll gain remote control, volume, six presets of customizable alternative settings for when you go from Paganini to Prince, maybe even one for the SVS.
Just a thought, and again I apologize.

Enjoy the deep end.   
I totally understand the trick adding subs is you shouldn't be able to differentiate between the mains and subs....they sould seamlessly blend and disappear. ......when l activate mine ...the best way to describe it is like a loudness button on steroids. ......one fellow Audiogoner said he went to a high end shop and was demoed a Rel sub to add to his system. ..he said he couldn't hear much of a difference and thought it was a waste of money. ...l belive source material is key...but everything sounds better with properly done subs......
When you use multiple subs, do you try to tune them differently to integrate more seamlessly or adjust them the same?
Im no expert by any means. ...but i discovered my subs were canceling each other out....a simple db meter worked well for me....changing the phase on them cured that problem. .......the rest of it was hours of listening and placement. .....level adjustment. ..crossover adjustments. ....but thats the fun stuff. ....when you hear the subs over the mains it sounds like crap.....when it sounds like everything coming from the mains you hit it.....if thats any help? Some source material doesn't need a whole lot and some needs more........
Im no expert by any means. ...but i discovered my subs were canceling each other out....a simple db meter worked well for me....changing the phase on them cured that problem. .......the rest of it was hours of listening and placement. .....level adjustment. ..crossover adjustments. ....but thats the fun stuff. ....when you hear the subs over the mains it sounds like crap.....when it sounds like everything coming from the mains you hit it.....if thats any help? Some source material doesn't need a whole lot and some needs more........
Ive found if you get up real early in the morning and can get a few hours to yourself  (good luck) put on a good pot of darkroast coffee and calibrate your system. ...you can  do your best thinking alone.... let your own ears be the judge. ..they will never steer your wrong...
You may be using too much of your svs subs . If your speakers are good to 29hz those 16 ultras will be running at a whisper and crossed as low as possible. Your room may not be able to handle the overlap of frequency . I run Cronus magnum ii into my 4430 horns and mc2300 into the 2235h woofers. I then use a bx63a to extract the lows to a pair of jbl 2245 18” in the 1983 design 12cuft enclosures (incredible beautiful response that makes your eyes well up ). Powered by two mc2300 amps bridged. The subs are tuned to 20hz . And barely have to move . It is all in the middle of the long wall of the room 56x36 x16h . Sometimes the bass feels like the room is a water bed . Silent low frequencies you can feel on your insides . And at moderately low listening levels . Anyways... start at an unnoticeably low level . Stop just after you can tell they exist. Also your placement may be too far into the corners or close to the wall . ..first post ever. 
I've just bought a couple of medium quality subs and after following Jim Smith's guide for proper subs set up, with an RTA on some steps, the 3D sound and bass energy Im getting from my system is incredible!
And I still have to keep on tunning them for better sound and then run Dirac Room Correction to get full perfomance.
Its incredible how the mids and the highs have improved with the subs. 
One suggestion, read Jim Smith's articles about adding subs:
https://www.psaudio.com/article/subwoofery-trick-or-treat/
Swarm + Room Correction and you are set. Cost about $7k new.
$3.5k used. $1.0 for the very patient smart shopper. 
In fact, you dont need a pro RTA, I did it with an Android app called Sound Analyzer App wich is enough for the job. 
You have to find the flatest bass response possible and doing it by ear is not an easy job. 
The app helped me A LOT to find the best location for the subs (among the ones I've had due to decor), the best direction, the correct phase and a good crossover-volume level adjustment. 
m-db,

     I'm sure you'll be thrilled to know that setting up a 4-sub distributed bass array system requires absolutely no bass room treatments, mics, DSP and room correction software or hardware.  Room correction is completely optional. 
      It's also scalable since you can use any 4 subs to achieve accurate, smooth and detailed bass with your choice of available bass power, dynamics and impact, from 4 small DIY subs to 4 JL Audio Fathom V2s and any bass quality and capacity levels in between.
     Since there's currently no recorded vinyl or disc source material with bass content below 20 Hz,  I'm using (4) two foot tall ported subs with one sq. ft.  footprints and 10" long-throw aluminum drivers that are flat down to 20 Hz at 113 dbs.  
     My DBA system provides accurate, detailed, smooth and natural bass that integrates seamlessly with my 6x2 ft. fast Magnepan panel speakers which are only capable of bass extension down to 35 Hz.  It works like a charm for music and ht.

Tim
firstnot:"Swarm + Room Correction and you are set. Cost about $7k new.
$3.5k used. $1.0 for the very patient smart shopper."


Correction:

Swarm + No Room Correction required and you are set.  Cost about $2,800 new, including 4 ported subs with port plugs and 1,000 watt class AB sub amp with controls for volume, phase and single band eq.
No used price known due to it being the last sub system you'll ever need or want.

Tim
 
vinny I think you figured it out- when it sounds like just the mains, that's what you want. Some recordings have great low bass but a lot have very little or none. This makes it real easy to set the subs too high and not realize it until you get the rare record with really good bass. The meter test CD thing can get you close but then I think it just takes a while of listening and tweaking. Duke said the same thing, expect to spend a while fine tuning the levels. Then you put on Welcome to the Machine, Seal, Bird on a Wire, something like that, totally worth it.

    Yes, the downside of using a custom DBA with 4 amplified subs is the need to adjust the volume, xover frequency and phase on each individually and do a lot of tweaking til you get it just right.  

    Buying the complete Audio Kinesis Swarm or Debra DBA kit for $2,800 has the advantage of these controls being set on the sub amp that controls the configuration on all 4 passive (no internal amp) subs as a group.  You also only need a single a/c outlet for the amp as opposed to 4 outlets for subs with internal amps.
    My room has a crawl space below and I ran all the connecting sub and amp speaker cabling through that.  
   I also agree with setting the xover frequency as low as possible for best integration with the main speakers.

Tim
The plate amps in the Rythmik subs provide all the controls mentioned by @Noble100: volume, phase (180 degrees via a continuously-variable rotary knob), x/o frequency (40-120Hz) and slope (2nd/4th order), plus damping, a rumble filter, one band of PEQ, and both line level (RCA jacks) and speaker level (binding posts) hook-up. There is no reason four of them cannot be implemented as a swarm. You will however need four AC outlets. ;-)
It is not only phase but arrival times that are important. Two woofers can be in phase at a specific frequency but if one is say 15 feet from the listening position and another 10 feet from the listening position the arrival times will vary and the woofers will be out of phase at all other frequencies. This will muddy the bass and soften the impact of bass drums and such. You can fix this by using digital delays on the speakers that arrive first so that they all arrive at the same time but this works only at one place which is really all I care about. Everyplace else in the room is "background music." There is more to consider than just acoustics. The best approach is to make the woofers function acoustically as one driver which they will do as long as they are within 1/2 wavelength of the highest frequency you care to reproduce. So if you are crossing at 100 Hz the woofers should be no farther than 5 feet apart giving an array 15 feet wide. Below 100 Hz this array will function as one driver giving you one arrival time pretty much anywhere in the room. Now you just have to adjust the arrival time to match your satellites which you can easily do with a tape measure. Try it.
@mijostyn +1
a swarm is even bass, not accurate.


vinnydabully

We have had many years relationship with our REL rep (was with Magico at one point),

and he shared the REL G1 Mark II’s idea with us , since REL’s specialty if u will, is Sub-bass with 2 channel systems. But perhaps the S Series would be your choice. The G1’s are 5500 each, and we have 2 stacks of 3 shown in the photo gallery. Amazing. The Wilson Alexx speakers are the left n rights. Even the T7i’s I have played with our M7900 that we took as trade-in, and it sounds amazing with the $1000 each x 2 sub base.

But the G1 MarkII’s sound Absolutely incredible sound when you use the 3 in what they call an array stack of 3.

But that may be more extreme than you desire. But they many levels of Sub Bass for 2 channel. And their speak-on connector system with connecting the red & yellow wires to the + side of one speaker and the black to the ground terminal on said speaker. And then do the same for other side.

It was fun setting the different frequency for reach, and then going in to experiment with phase.  Very easy to work with.

Here is our high end listening room (the photo of the G1’s is in the slideshow at bottom of page, sorry, I took the photos w iphone, but the REL stacks of 3 you can see behind the Wilson Alexx speakers. In the top of page photo u will see JL Audio f212’s but those are now in the back of the room used for 5.1 only. The G1’s are for 2 channel and have high level connection, and then for 5.1 listening, we then use LFE:
http://audibleimagesav.com/the-transporter/

https://relsupport.zendesk.com/hc/en-us/articles/115004648928-Differential-Amp-Connection-Method

I use the T5i with my little NAD 3020 office system with a couple of MartinLogan Motion 2’s and it sounds great. :)

Art H.


A single sub, with bass traps and DSP, when optimally placed, is an amazing thing. People keep adding more subs, and more complexity because they never heard the single sub well integrated to begin with.
Unpacked the second set of subs this morning and fired em up.I haven't fussed with finding perfect placement yet but it's sounding really good already.The room is energized in a way that I can actually feel it on my skin.Not boomy or overblown whatsoever.Acoustic and electric bass sounds more natural and three dimensional.It's one of those moments where I just relax and know that this is the way it's supposed to feel.Like when you find the perfect compliment of tubes for your amp or get your speakers positioned perfectly.Sigh...there it is.
I was happy with the two subs but this is definitely a step up.
All the Phase Control on the Rythmik plate amps is, is a delay circuit; it achieves the same end as physically moving the sub enclosure to a different location. 1ms (the control has millisecond markings) equals roughly 1’. The control can of course only move time in one direction, into the future. ;-)
Vinnydabully,

i wonder what you do to be able to afford speakers costing $109,000.  Are they really worth the money.
I have bern right around Audio as a Audiophile over 35 years and Audiostore
owner until 08 . Have owned every major brand subwoofer in the past 3 years .
without question the best subwoofer with the most technologies by a customer untrue mile trickle down technologies from their flagship SVS ultra-16
is the Hot New SB 3000,13 inch sub Loaded with anything  no it does not has Bass EQ, but potentially much better , great app, powerful amp he only split voice technology in the world and makes a big difference at low volumes,not boom ,the center is smalller , for at low volume levels, as you crank it up,
it then uses the outer portion  50 MHz,52 bit Analog devises processor 
Nobody else has this high tech built into a under $2k sub ,at $995
i could not find better at 2x that it is that good. And I will probably buy a second sub ,for 2 good subs are always better then one to balance the room out .
even with one sub this Sb 3000sub is far moretunefull then any rel, $1500 JL audio I sold, rythmik,Velodyne, Syzgy,just go to utube, and see all the great reviews 
it is has been  out only 6months and is  the best under $2k sub on the market .
real tuneful articulate bass. It even has a 3 band parametric eq .
if you buy a usb Mike, Free REW Room wizardfree  Room software you can totally Taylor your room exactly to your preference with a little time and experience . Just check it out , who else will give you free shipping , a 45days
audition and they will pay for the return, and a full 5 years parts and labor.
that is truly having confidence in their product . The $3500 JL fathom ,ar$3500
was the only sub to be neck and neck with the $1995 SVS Ultra 16, the 
New baby brother SB-3000 has -0 competition ,even their 4000 model does not have the latest technologies , just bigger amp slightly bigger driver.
this 15 x17 sub with 13 inch driver is without peers . My brother has 2 SVS ultra 16 and he even agreed this sounds like a smaller  brother.
just check it out  Fantastic !!

bdp24:

"The plate amps in the Rythmik subs provide all the controls mentioned by @Noble100: volume, phase (180 degrees via a continuously-variable rotary knob), x/o frequency (40-120Hz) and slope (2nd/4th order), plus damping, a rumble filter, one band of PEQ, and both line level (RCA jacks) and speaker level (binding posts) hook-up. There is no reason four of them cannot be implemented as a swarm. You will however need four AC outlets. ;-)"

Hello bdp24,
     When did I state that you can't use four Rythmik subs in a swarm type (4-sub distributed bass array) system?   
     The answer is I didn't.  You can use any 4 self amplified subs you'd like to create a custom DBA system.  
     What I stated is that, if you choose to use 4 self amplified subs (like the Rythmik) to create a custom DBA rather than an Audio Kinesis Swarm or Debra complete kit DBA (which consists of 4 passive subs and a separate amp/control unit to power and configure all 4 subs as a group), then the setting of the volume, xover frequency and phase controls will need to be done individually for each sub rather than all at once as a 4 sub group on the AK sub amp/control unit.  
     My intent being only to inform readers of this fact so they can make an informed decision on whether to choose between a custom DBA system using 4 self amplified subs and a complete custom or AK DBA system using 4 passive (unamplified) subs.  
     In fact, I believe using 4 self amplified subs, like the Rythmic with individual volume/xover/phase controls, does offer more configuration flexibility than setting all these controls for all 4 passive subs as a group on a sub amplifier/control unit.  It's just that it complicates DBA configuration, requires more time and is an individual choice best made with full knowledge.
     The key to the DBA concept working so amazingly well is the use of at least 4 properly positioned subs, the fact that it works extremely well with  a wide variety of sub types, sizes and quality just demonstrates the validity and flexibility of the DBA concept.

Tim
larry5729

Were u talking to Vinny or Me Larry?

I posted the theater link where we have the Wilson Alexx speakers.  But no price. They are $109 K/pair. Except the link lead to the page that priced out the system.  
My boss and former roomate from school owns the showroom, and yes, the Wilson Alexx speakers are certainly worth every penny for the sound.

If someone has the money, and can also have a dedicated, full blown treated room as good as the custom listening room that Robert Harley shared in an article in an issue or two ago, then yes you can totally hear it.  It is really enjoyable to just have folks come in for a demo in all 3 listening rooms, saving the "Transporter" room for last.

I enjoy MartinLogan ESL's (2500/pr) , I enjoy PSB Imagine B speakes (1300/pair), I have MartinLogan Motion 2's in my office with a REL T5i, which sounds great.  You just shift gears when you listen to a pair of Wilson Alexx with D'Agostino Progression mono blocs.

I love listening to Vinyl in there, and then comparing it it to streaming from Tidal, using Roon, thru the Vivaldi DAC and dCS Network Bridge. Usually the Vinyl has greater detail (Brinkmann Bardo turntable w Audio Research Phono 3 preamp), but many times a solid MQA Master recording gives the Vinyl a run for it's money, almost :) 


http://audibleimagesav.com/the-transporter/


audioman58

I would really like to hear  SVS ultra-16 and the New SB 3000 you mentioned.

Blending a single sub or a pair with 2 channel system does make all the difference in the world.

Pretty cool you had a store till 2008 !

     I thought it would be useful to cut and paste a response from Duke Lejeune, owner of Audio Kinesis and advocate of the DBA system concept, from a thread I started awhile ago on the DBA concept. Here's a link to the full thread followed by Duke's relevant response:

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


Duke:

"Just for the record, I got the distributed multisub idea from Earl Geddes. It happened like this:

I was driving Earl to the airport after CES in January of 2006 and we were stopped at a stoplight. He said to me "Duke, I’ve figured out how to get good bass in a small room. Use four small subs and distribute them asymmetrically. Each will produce a different room-interaction peak-and-dip pattern, and the sum of the four dissimilar peak-and-dip patterns will be much smoother than any one alone." A lightbulb went off in my head as I immediately realized this was "the answer", so I said, "Can I license that idea from you?" He replied, "You can just use it." And then the light changed. It was that fast.

Now let me explain what I meant by "the answer": For years I had been trying, off and on, to build a subwoofer that was "fast enough" to keep up with Quads and Maggies. I was a SoundLab dealer, and the SoundLabs are big enough to have good low-end extension, but they are too big and expensive for most people. I figured the first guy to make a sufficiently "fast" sub would have a potential market among Quad and Maggie owners. Being a longtime amateur speaker builder, I tried pretty much everything except for a horn: Sealed boxes, aperiodics, low-tuned vented boxes, transmission lines of many different geometries, equalized dipoles, and isobarics. None of them could "keep up" with Maggies and Quads. I was stumped.

But the problem was not the "speed" of the subwoofer - it was the peak-and-dip pattern that the room inevitably superimposed on the sub, which totally dominated the result. Yes some subs were audible improvements over others, but none could blend with Maggies or Quads without there being a distracting disconnect between the subjective lack of "speed" in the low bass and the rest of the spectrum.

You see, woofer(s) + room = a minimum phase system at low frequencies. What this means is, the frequency response and the time-domain response track one another. In English: Where you have an in-room response PEAK is where the decay is SLOW, and it doesn’t matter how "fast" the woofer is. The good news is that, when you fix the frequency response you ALSO fix the time-domain response, and vice-versa! So, SMOOTH bass is FAST bass. This is why the lightbulb went off in my head when Earl described his idea to me.

A distributed multisub system like the Debra or Swarm or your own set of four subs results in four (inevitably nasty) peak-and-dip patterns, but their sum will be much smoother than any one of them. Actually you will end up with MORE peaks and dips, which will be much smaller and much closer together. This "closer together" part is quite beneficial - the ear tends to average out peaks and dips that are within 1/3 octave of one another. So the subjective improvement is often greater than one would expect from merely eyeballing before-and-after curves.

One of the things to be aware of if you’re going to "roll your own" distributed multisub system is this: At the upper end of the bass region the outputs of the subs will be combining in semi-random phase, but at the bottom end of the bass spectrum their outputs may well be combining in-phase or nearly so, if the longest room dimension is a small enough fraction of a wavelength. This results in a rising response as we go down in frequency (and remember that the time-domain response tracks the frequency response). So if you already have two subs that go real deep, you might do better by adding two more that do not go as deep. Or vice-versa.

In the Debra and Swarm systems, the subs’ native response curve falls by about 3 dB per octave from 80 Hz down to 20 Hz. This approximately compensates for typical room gain. Then in most rooms we reverse the polarity of one of the subs (usually the one farthest from the main speakers), and this extends that semi-random-phase addition down into the bottom of the bass region, further smoothing the response and offsetting the rising bottom end that we would otherwise have. Also the down-firing ports on the Debra and Swarm modules are pluggable, converting the enclosure into a low-tuned sealed box, to give further adjustability (given that every room is different). And finally, the amp that we use has a single band of parametric EQ, in case there is still a peak at some frequency.

Speaking of EQ, why not use a single sub with EQ to fix the frequency response curve, simultaneously fixing the time domain response? EQ works great at a single listening position, and can work well within a small listening area. But the larger the listening area that we try to improve with EQ, the smaller the improvements are going to be. This is because the afore-mentioned room-induced peak-and-dip pattern changes dramatically as we change locations within the room ,so EQing a single subs works best for a single location. Unfortunately when we fix the frequency response in one location, we are making it MUCH WORSE in other locations! This is because the peaks and dips are at different frequencies at other locations. But with a distributed multi-sub system, the spatial variation (difference in frequency response from one location to another) is also greatly reduced. So if by chance there is still a peak with a distributed multi-sub system, chances are it’s a GLOBAL (room-wide) rather than a LOCAL peak, and therefore is a very good candidate for correction via equalization.

Big rooms have smoother bass than small rooms because they have a more dense modal behavior: The room-induced peaks and dips are more numerous and more closely spaced. A distributed multisub system can make a small room mimic a larger room in the bass region by doing the same thing. And this will sound counter-intuitive, but the smaller the room, the more it will benefit from a distributed multi-sub system.

One other bit of trivia: The other main researcher behind distributed multisub systems is Todd Welti of Harmon International. He investigated symmetrical rather than asymmetrical arrangements. Anyway Earl and Todd were developing their ideas AT EXACTLY THE SAME TIME, but each was completely unaware of the other’s work. So I guess it was an idea whose time had come!

Robert E. Greene of The Absolute Sound gave the Swarm a Golden Ear award again this year (It got a Product of the Year award back in 2015). So despite the passage of time, apparently the distributed multisub idea hasn’t become outdated.

Duke

dealer/manufacturer/caught in limbo?"


      I think this explains why the time-domain is much less important on deep bass response than some seem to believe it to be.  It also explains the importance of how our brains process the presence of multiple bass peaks and dips at multiple frequencies in a room, referred to as psycho-acoustics, which is a bit counterintuitive but is a crucial factor in how a DBA so successfully utilizes the differentiation between the physics of how deep bass very long soundwaves behave in a given room and how we perceive those soundwaves.  

     I admit I don't understand this subject in detail but I can state with certainty that the concept produces what I consider state of the art bass response in my system and room without the use of any room correction software or hardware, DSP, equalization and bass room treatments.  

     I know I'll always have this excellent deep bass foundation that seamlessly integrates with not only my current main speakers on music and ht, but it will do so equally well with any main speakers I may use in the future.  I've found my huckleberry.

Tim

Vinny, did I mention you've gone and done it?
You've made your purchase and the well meaning suggestions just keep on rollin' in. 
Subwoofing is getting popular...


Tim, actually I'm more impressed than thrilled by the economy and positive user comments regarding your DBA Swarm system. You have created a user friendly solution to an often ill informed segment interested in true full range listening. 

I've misplaced a list compiled a few years back of recordings that contain ELF below 20Hz. My Mastering acquaintance in SoCal describes spending great amounts of time mastering the ELF for many of his customers. He's using modified Duntechs/Danley Sound Labs setup for playback. I'm sure we've all heard some of his work misrepresented while driving around.  
jtcf:
"Unpacked the second set of subs this morning and fired em up.I haven’t fussed with finding perfect placement yet but it’s sounding really good already.The room is energized in a way that I can actually feel it on my skin.Not boomy or overblown whatsoever.Acoustic and electric bass sounds more natural and three dimensional.It’s one of those moments where I just relax and know that this is the way it’s supposed to feel.Like when you find the perfect compliment of tubes for your amp or get your speakers positioned perfectly.Sigh...there it is.
I was happy with the two subs but this is definitely a step up."

Excellent, welcome to the  DBA system sota bass response club, jtcf! I know exactly how you feel, it really is like a revelation the first time you hear the stunning quality and integration of the bass produced by a good 4-sub DBA system in your system, with your music and in your room.
It really makes me wonder why this concept isn’t more widely known of and utilized, especially by Audiogon members.

Congratulations,
Tim


Thanks Tim!It really is pretty amazing:)I think a lot of people don't take it seriously when they first run across the concept.At first glance it doesn't seem to make any sense.The more I researched the more convinced I became.I really believe that multiple subs and room treatments are necessary to get the best out of a music system in moderate sized rooms.
m-db:
"Tim, actually I'm more impressed than thrilled by the economy and positive user comments regarding your DBA Swarm system. You have created a user friendly solution to an often ill informed segment interested in true full range listening. "


Hello m-bd,

     Thank you, but I didn't create the excellent DBA system solution.  All the credit belongs to Dr. Earl Geddes, Dr Floyd Toole, Todd Welti, Duke Lejeune plus probably others I'm unaware of that also made contributions to the concept. 
     My contribution was just to have the dumb luck to give the Audio Kinesis Debra 4-sub DBA system a try and almost immediately recognize how extraordinarily well it actually performed.
     The first time I experienced the quality of the bass reproduced by the 4-sub Debra DBA system and how seamlessly the bass integrated with my main speakers, I sincerely felt it was a revelation and an awakening to actually hear and physically feel this level of bass quality and integration with my music, on my system and in my room.  
     Initially, all I wanted to do was enjoy my significantly upgraded system for hours upon hours on musical and ht content while constantly reminding myself how fortunate I was to have this DBA in my system.  4 years later, I'm still enjoying it just as much.

     After a few weeks of first experiencing the DBA's extraordinary bass performance, I came back to earth enough to be perplexed about why it took so long for me to learn of the DBA concept and why more Audiogon members apparently weren't aware of and utilizing DBA systems.
     At this point, I felt an obligation to get the word out about how exceptionally well this DBA system concept actually performed in my system/room and how it was likely to perform at least equally well in others' systems.  
     So, I began by starting an Audiogon thread on the DBA concept linked to below: 

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

     I've also been trying to get out the word on the effectiveness of DBAs by consistently trying to post responses on threads on this site concerning the use of subs, such as this thread extolling their virtues.  I'm not sure how successful I've been but I'm going to keep trying to spread the word.  I  find it very difficult to overstate how well the DBA system actually performs in my system, know it will do the same in any system regardless of the room and the main speakers used and believe it's too good of a bass solution not to eventually be well known and widely utilized. 


Tim
Erik squires is right , proper calibration ,and a  high quality sealed sub is allways 
more accurate then the same size in a ported ,or passive radiator model.
buy a usb Mike, and this free program   http://www.roomeqwizard.com
And just spend a little Time to get to learn it .with the excellent SVS app
you can accurately tune the bass in any room.
@noble100, I agree, you didn't state that you can't use four Rythmik subs in a swarm type system. Ya know what I didn't say? That you DID say that. Why do you think I think you think you did?
I use a pair of Audiokinesis Dream Maker speakers, plus a pair of their LCS "effect" speakers firing towards the ceiling. I just want to point out that the LCS helps with the bass too, although their main purpose is to enrich the total sound (a variant is called "Space generator"). Each LCS has two 8 inch woofers and a tweeter. Combined with the two 10 inch woofers in each main speaker there is quite a lot of "woofer power" which fills my 20 x 27 feet room nicely. Although the bass would probably be even better with a Swarm or Debra system, I can do some of the same thing - position the LCS for best bass, ’decorrelate’ the sound, etc. I had a Velodyne DD18 sub that went deeper, but also introduced tension in the sound (and two REL subs before that). All in all I prefer the system I have now. In my system it is important to fine-tune the volume of the effect speakers relative to the front speakers "just so" - and further down than I thought at first. They should almost not be heard, "disappearing" behind the front speakers, yet adding to the total sound experience.
bdp24:
"@noble100, I agree, you didn't state that you can't use four Rythmik subs in a swarm type system. Ya know what I didn't say? That you DID say that. Why do you think I think you think you did?"

     Hello bdp24,

     Okay, you may not have said it directly but it's a simple, unambiguous inference to make from your post comment in which you referenced myself, quoted below:

"The plate amps in the Rythmik subs provide all the controls mentioned by @Noble100: volume, phase (180 degrees via a continuously-variable rotary knob), x/o frequency (40-120Hz) and slope (2nd/4th order), plus damping, a rumble filter, one band of PEQ, and both line level (RCA jacks) and speaker level (binding posts) hook-up. There is no reason four of them cannot be implemented as a swarm. You will however need four AC outlets. ;-)"

     In any case, I agree that four Rythmik subs implemented as a DBA have all the required controls and would likely result in a high quality bass system.

Thanks,
  Tim

Tim, I think you need to drop your Adderall dose:) Sub woofers are not more prevalent in high end audio because they add expense, they take up space and women do not like the looks. Not to mention that there are still many audiophiles who think sonically they are a detriment.  All this seems to go the way side when you are talking about theaters. Back in the 70s when I started using subs (RH Labs) I got all kinds of flack from the audiophile community about how they were impossible to integrate and sounded awful and how could I do that to my system la di da. Actually, back then they were right. I started off with one sub and now matter what I did I knew I was listening to a box between my ESLs. So I got another sub and mounted the ESL panels on top of them which made a distinct improvement but I could still hear the cross over. All we had back then was the Dalquist DQ 1. So I spent the next 2 years messing around with the crossover. The system could be impressive but I never though it was accurate. In 1981 I had to move from Miami to Akron so I sold the system to my room mate who had no idea what he was listening too. In Akron I got a set of Acoustat 2+2s and a set of Krell KMA 100s.
In the small apartment I was in I never felt the need for subs with this system which was glorious. In 1987 I sold just the speakers and moved back to New England where I got a pair of Apogee Divas, all the rage at the time. The Divas did not do low bass and I felt that the speakers would sound better if I subtracted the very low end from them. So, I got a pair of the early 12" Velodyn Subs. They were sort of OK but the Divas really perked up. I could never really integrate the subs well enough that they disappeared. Then I got my first TACT preamp with full digital bass management and room control. Instant bliss, huge improvement. But, the two woofers could not match the power of the Divas. Analyzing the situation I realized that the only way I was going to get sub woofers to match the output characteristics of a linear array was to make a linear array with the sub woofers. We are now in the late 90's I think. Looking at the subs available on the market then there was not one that suited my purpose. All I needed was a passive sub. So, I built 4 subs using what is now called the Ultimax 12" sub woofer by Dayton. The enclosures were made of solid surface material laminated to 1" MDF and designed with a Q of 7.4. Each one weights almost 200 lb. I got commercial 1200 watt/ch AB amps with damping factors of 500 into 4 ohms, one for each channel. The subs were arrayed across the front wall at 5 ft intervals but off the wall. This resulted at least 10 db standing waves in the room. I had to get rid of the reflection off the front wall so I spun the middle subs side ways and pushed them right up against the front wall facing each other  The corner subs were already against the side walls. The standing waves all but disappeared. I re calibrated the room control and after five minutes of listening to Return for Forever's Romantic Warrior I knew I finally had it licked. That was with a cross over at 100 Hz I eventually took it up to 125 Hz. Around 2000 I was asked to do a system on the Cape for a friend of my Brothers who I had set up with Acoustat 2+2s years before. He decided to go with Maggies and new electronics (less selfish). When I was finished I was walking out the door and he asked me if I was going to take the speakers. "Do you want me to sell them for you?" "No, you can have them."   So, I inadvertently waltzed  into a pair of mint 2+2s. I sold the Apogees and have never looked back. I guess the moral of the story is that it takes a lot of screwing around to get things right.
What is everyone's take on Hsu subwoofers? They were kind of a hot item a few years ago,but I haven't heard much lately.
mijostyn:
"Tim, I think you need to drop your Adderall dose:) Sub woofers are not more prevalent in high end audio because they add expense, they take up space and women do not like the looks. Not to mention that there are still many audiophiles who think sonically they are a detriment."

Hello mijostyn,
    
     I'm not going to blame my Adderall dosage, it was probably due more to the multiple bottles of whiskey and all those speedballs.
     Concerning your reasons why sub woofers aren't more prevalent in high end audio, you may be correct but I can only respond from my personal perspective.  My subs were an added expense but worth every penny, they don't take up much space at 1x1x2 feet each with 2 not even visible positioned behind my panel speakers, my wife likes the looks of the other 2 that are visible and usually has a vase of fresh cut flowers on one of them. 
      I don't like referring to myself as an audiophile because it reminds me of a crusty old rich pretentious guy blindly following audio doctrines of dubious merit, like the audiophile purist doctrine that subs are sonically a detriment that I envision some audiophiles blindly believing in for decades but never bothering or daring to find out for themselves whether or not the dusty old doctrine even has merit. 
     I consider myself more of a practical, reasonable and independent sort with an open mind, a belief in the scientific method, an appreciation of high quality audio/video equipment but utmost a lover of music and movies who's constantly searching for and learning about improved methods of reproducing both in my home system.  Perhaps I'm such an avid fan of the 4-sub DBA concept because it's so compatible with my concept of myself. 
      You've had a very practical and interesting history with speakers and subs.  I consider Apogees and Acoustats to be very similar to Magnepans, excellent fast type speakers that are a bit lacking in deep bass impact and dynamics that are also all recognized as being difficult to successfully integrate subs with. 
     I'm very curious how well those 4 Dayton subs you built would have integrated with those speakers if you were aware of and utilized the DBA concept  in configuring and positioning them.  Based on my knowledge and experience, I think it's likely they'd have worked very well.


Tim    
Following doctrine gets you absolutely no where. Good for you. I started messing with subs because I knew theoretically they should be a huge benefit particularly with a planar speaker that has limited excursion capability and is a dipole. I would be happy to send you a picture of the whole array. It is set up on a radius from the listing position forming a segment of a circle. The subwoofers are position so that the face of the driver is in the null of the ESLs which is directly to the sides. Dipoles have a figure 8 radiation pattern. Even without room control this works pretty well but without digital bass management, given my experience you are sunk. All the amplifiers are downstairs on a shelf up against the ceiling right under the speakers. The ESLs are 3 feet from the front wall and the subs are positioned so that their drivers are right up against a wall two between the ESLs up against the front wall and two to the outsides up against the side walls. Acoustically these subs are acting as one big driver 16 feet wide forming a linear array of infinite length. Linear arrays like the ESLs do not radiate to the sides, up or down. This is a huge benefit preventing as least 4 of the primary reflections in the room. The result is that no matter where you go in the room except right up against the walls the bass output at any frequency is the same. No standing waves that you can hear. You can not tell there are separate subs in the system. the presentation is one big whole or rather all the speakers disappear. The only disadvantage is that you can tell exactly how bad most recordings are engineered.
Hello mijostyn,

     Very unusual and interesting.  I think I understand your setup but I'd love to see a picture.  Or you could fill out the system section on your profile and upload pictures for future reference.

     The way I understand it, you're main speakers are ESLs (Quad ESL63s or possibly even a newer model?) that are positioned about 3 feet out from your front 16 ft. wall.  All four of your Dayton subs have front firing 12" drivers that are facing the walls, 2 between the ESLs and 1 near the front of each L+R side wall, perpendicular to the side of each L+R ESL speaker (the null area) and facing the wall.  Am I correct?
    My subs are all front firing subs with the drivers facing the wall but have 10" drivers as opposed to your 12" drivers.   I also have 2 subs along my front 16' wall with one positioned behind each of my 6 x 2 ft. Magnepan panels that are straddling a large hdtv, about 8 feet apart and 4 feet out from the front wall.  There's also a sub along each of my 23 foot side walls with the left sub about 1 ft away from the left rear corner and the other about 2 ft away from the right rear corner.  My listening  seat is in the middle of the rear 16 ft rear wall and in between these 2 rear subs.       Even though there's a sub on each side of my listening chair within 8 ft away, I never perceive the bass as originating from either one (no localization of bass).
      You're using a linear bass array configuration and I'm using a distributed bass array configuration, but it sounds like we're both getting very similar high quality performance results; accurate, detailed and extended bass response with no standing waves you can hear and seamless integration.
        I'm interested in your system and was wondering about your room dimensions, what you use for bass management and whether you use it for music only or ht, too.


Thanks,
  Tim
Tim No, Right now I have modded out Acoustat 2+2s. Quads are not linear arrays. Full range linear arrays have to extend from the floor to the ceiling. I am on the brink of getting SoundLabs Majestics 845s as I have 8 foot ceilings. Between the speakers is a theater screen. The sub drivers are front firing. The inner two actually face each other with three feet between them. This gets the driver closely coupled to the front wall. 
The outer subs are against the side walls facing forward. Their drivers are closely coupled to the side walls. The main speakers are angled towards the listening position. A line extending through the sides of the speakers will intersect the faces of both subs on its side.
Your Maggies are linear arrays down to about 150 Hz where they convert to point source. In order to get the full linear array effect you would have to cross to the subs no lower than 150 Hz. But then your subs would have to be closer together, about 3 feet. I wish Maggie would make a speaker with 8 foot woofers. It would make life much easier.
I hope your listening position is not right against the wall. If it is move it forward a couple of feet. Sound waves are very slow. You have two subs back there with you and you hear those fractionally before you hear the ones on the front wall. This will smear transients. You want to hear all your subs at exactly the same time. You also have dipoles so you want all your sub drivers in the null zone beside each speaker. If your TV is mounted on the wall up off the floor you can put two woofers between the Maggies facing each other right up against the wall under the TV. Now If you try crossing at 150 Hz the subs will have to be no farther apart than three feet. So you would array them across the front wall and up the side walls three feet apart.You do not want to put a sub behind the Maggie. It will cause weird interactions with the woofer panel which is why I locate them in the null zone. With your woofers 3 feet apart they will all act as one driver and you will hear all of them at the same time. If you move them further apart and cross lower, 100 Hz cross puts the subs 5 feet apart you will have a very important segment of the bass drop into point source mode and that segments volume will drop off rapidly as you move away from the speakers. I wish Maggie would make their big speakers 8 feet tall, actually 7' 10".
The room is 16 X 60 feet sort off. The system spends much more time playing music but it does TV and Theater duty. I have no need for rear speakers or a center channel. I have a digital preamp which includes room control and the best bass management ever made. I can adjust cross over points and slopes on the fly. I have up to 10th order slopes and the cross overs can be adjusted in 1 Hz increments. I also have complete control over levels. Thus I only need passive subs and I am much happier choosing my own amps. The only unit that comes close is the Trinnov Amethyst. There are stand alone digital bass management systems out there. I believe DBx makes one. Sanders uses it in his speakers. There's another one who refuses to make his speakers taller. Talking about bad recording engineering. I was just listening to Neil Young's Harvest. The snare drum is right in your face and Neil and his guitars are like 50 feet behind. Pretty surreal.