What are considered to be the best Subwoofers for 2 channel music only ?


I am just about to pull the trigger on a REL Studio Subwoofer, price is £1000 includes delivery. Before I do. can anyone please offer advise on a better Sub for approx. £1000 ? I have read good things about SVS Subwoofers but I have had no experience with these, The Studio in its day was approx. $7000, but my guess in todays market them figures mean nothing. When designed and built the REL Studio was all UK, now American owned (good thing right ?) china built (not so good thing right ?). I  would really appreciate the advise, Thank you.
select-hifi
No idea the cost in pounds sterling but four subs in a distributed bass array (like the Audiokinesis Swarm) is by far the best way to go.
http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/
I would stick with REL, they are the best subwoofers I have tried and tested in a 2 channel system. They may have changed ownership but the design philosophy is still pretty much same as before with subtle improvements.
I have had a lot of subwoofers and for 2 channel playback you cannot go wrong with REL. Their speakon connectors make for a seamless integration.
Would you go 1 S3 or 2 T9i ?  Thank you
The Eminent Technology TRW-17 Rotary Subwoofer. And when Bruce Thigpen says subwoofer, he means it. For the reproduction of 20Hz and lower, output down to 1Hz!

A repost and good summation of the conflicting strengths and warts in setting one up properly and more importantly , first considerations  you would undertake to do so.

http://ultrafi.com/why-everybody-needs-a-good-subwoofer/


August 3, 2008 by ultrafi in Tips, Tricks & Info | Comments Off on Why Everybody Needs a Good Subwoofer

" …And Why a Really Good Subwoofer is so Hard to Find

Audiophiles and music lovers are missing out on one of the most dramatic improvements they can make to their audio system: Powered Subwoofers. Most audiophiles won’t even use the word “subwoofer” in public, let alone plug one in to their precious systems. There is a kind of snobbery that exists in the world of high-end audio aimed primarily at receivers, car audio, home theater and especially subwoofers. As a matter of fact, subwoofers are responsible for many people disliking both car audio and home theater, since it is the subwoofer in both of those situations that tends to call attention to the system and cause many of the problems.

The truth of the matter is that subwoofers have fully earned their bad reputation. They usually suck. Most of them sound boomy, muddy and out of control with an obnoxious bass overhang that lingers so long as to blur most of the musical information up until the next bass note is struck. We have all had our fair share of bad subwoofer experiences, whether it’s from a nearby car thumping so loud that it appears to be bouncing up off the road, or a home theater with such overblown bass that it causes you to feel nauseous half-way through the movie. You would think that high-end audio manufacturers would be above all of that, but you would be wrong. In many cases, their subwoofers are almost as bad as the mass-market models because they too, are trying to capitalize on the home theater trend that is sweeping the land.

You see, it’s very difficult and expensive to build a good subwoofer. One reason is that a sub has to move a tremendous amount of air, which places big demands on the driver (or drivers). Moving lots of air requires a lot of power and that means an amp with a huge power supply, which can cost huge money. Finally, in trying to move all of this air, the driver (or drivers) which operate in an enclosure, create tremendous pressure inside of the box itself. The cabinet walls must be able to handle this pressure without flexing or resonating. Building such a box involves heavy damping and bracing which gets very expensive. When you consider these requirements, you quickly realize that it is virtually impossible to build a really good subwoofer (I mean good enough for a high-end music system) for under $1000. Yet most of the subwoofers out there sell for between $500 and $900. Manufacturers do this because their marketing research has shown them that that is what people want to spend on a sub, never mind the fact that what people want to spend and what it takes to get the job done right may be two different things. The result is that even most high-end manufacturers are putting out poorly constructed subwoofers that just don’t sound very good.

I don’t want to give you the impression that anyone who really wants to can build a good subwoofer so long as they are willing to throw enough money at the problem, because that really isn’t true either. There are some pretty expensive and well-constructed subwoofers out there that you would never want to plug into your music system because they would most certainly make the sound worse. Why? Because of their crossovers. A crossover is inserted into your signal path in order to remove the lowest frequencies (the deep bass) from your main speakers so that they no longer have to do all of the dirty work. The deep bass will instead be dealt with by the subwoofer. The #1 benefit of adding a high quality subwooferto your system is not how it further extends the bass response, but how it can dramatically improve the sound of your existing power amp and main speakers from the midrange on up. That, my friends, is by far the most compelling reason to add a sub to your high-end music system. Once your main speakers are freed from the burden of making deep bass, they will sound cleaner, faster and clearer, especially in the midrange and midbass. They will also image way better because there will be far less air pressure and therefore resonance and vibration affecting their cabinet walls. And since the power required to make the deep bass is provided by the subwoofer’s built-in amplifier, your main power amp will be free from that burden and begin to sound like a much more powerful amplifier. The one big problem with all of this is that you need a crossover to roll off the deep bass in your system and achieve all of these benefits. And the crossover that comes with almost every subwoofer on the market will cause more damage to your signal than can be overcome by these benefits. That is the main reason that audiophiles refuse to consider adding subwoofers, even very expensive ones with well built cabinets.

Enter the Vandersteen 2Wq 300 watt powered subwoofer. This is the only subwoofer that is specifically designed to be inserted into the highest of high-end music systems without doing any harm to the precious signal. So how does Vandersteen do it? Simply. In fact his crossover scheme is so ingeniously simple that it’s a wonder nobody else thought of doing it the same way. I’ll spare you an in-depth description and just say that the only thing you end up inserting into your system is a couple of high quality capacitors. That’s it, nothing more! No additional wires or gadgets enter your signal path. Hell, you don’t even have to disconnect the wire between your amp and speakers to add this subwoofer. The model 2Wq sub uses the same basic crossover scheme as the $15,000 flagship Model 5As. As a matter of fact, you can even run the specially designed Model 5A crossovers (M5-HP) with the 2Wq if you want the most transparent sound imaginable.

So what about the other reason to add a subwoofer to your system: for more powerful and extended bass? I don’t care how big your main speakers are, they’re no match for a good subwoofer in the bass. A really good subwoofer can run rings around the best floorstanding speakers when it comes to bass extension, power and control because it is designed to be good at that and nothing but that, whereas main speakers have to be good at higher frequencies as well. Ideally, you want two subwoofers so that you have true stereo separation down deep into the bass. Stereo subs can also help to lessen room interaction problems by providing two discrete sources of bass information. Remember, if you can’t afford to buy two subwoofers at once, you can always add the second one later. Adding a pair of 300 watt powered subwoofers is exactly like adding a pair of 300 watt monoblock amplifiers to your system and upgrading to a pair of better main speakers at the same time. The beauty is that you don’t have to replace your main power amp or speakers to do it.

But there is a problem here as well. Everything comes at a price, and the price you pay with most subwoofers is that when you add them and their built-in amplifiers to your system, they don’t tend to blend or integrate well with the sound of your power amp and speakers. This is especially true if you own a tube amp, because the character of your amp is nothing like the character of the big solid-state amp that is built into most subwoofers. The result is that your system sounds split in half. You can hear where one part of the system leaves off (namely your amp and speakers) and where the other part takes over (the sub and its amp). This is a HUGE problem for audiophiles who aren’t willing to destroy their system’s coherence for additional power and bass extension. Fortunately, Vandersteen has the perfect solution for this problem that is, again, so simple, I wonder why nobody else thought of it first. His solution is to build a very powerful 300 watt amplifier that strictly provides the huge current needed to drive the subwoofer. You can think of this amplifier as only half of an amplifier; or just the power portion of an amplifier. The release of this power is controlled by the signal that is provided by your power amp. Vandersteen’s amplifier needs a voltage to modulate its current output, and what better place to get that voltage than from your main power amp? This way, your power amplifier is directly responsible for the sonic character of the deep bass coming from the subwoofer because it provides the necessary voltage signal. This voltage signal contains the unique and characteristic sound of your main power amplifier and insures that that character is maintained in the sound of the subwoofer itself. The beauty of it is that your amplifier is only providing a voltage reference and no actual current, so it is not taxed with the burden of “driving” the subwoofer in any way. As a matter of fact, your amplifier doesn’t even know that the sub is connected to it. The 2Wq’s potential is almost unlimited given that it will ratchet up its performance as you improve your power amp. Remember that you always want your subwoofer to sound just like your power amp. No better, no worse. NO DIFFERENT!

After having spent time with the amazing Vandersteen Model 5A loudspeakers with their 400-watt powered, metal cone subwoofers, we were reminded of the sound we had with the awesome Audio Research Reference 600 mono power amps. With the Ref 600s there was a sense of effortlessness, openness and unrestricted dynamic freedom that we have only otherwise heard with live unamplified music. Listening to those monstrously powerful amps made us realize that all other systems sound compressed by comparison. Only when we heard the new Vandersteen Model 5As with their hugely powerful built-in subwoofers, did we again have a strikingly similar sonic experience. The reason is that the Model 5As provide a total of 800 high-quality watts, to which you have to remember to add the power of the amp we were using, the ARC VT-100, at 200 watts. This means we were listening to about 1000 total watts of amplifier power – not far from the 1200 total watts provided by the Ref 600s. With the Vandersteen subwoofer crossover and amplifier, you are able to get those hundreds of subwoofer watts to blend seamlessly and even take on the character of the ARC VT-100. It’s amazing! What’s even better is that the price of the system with the Model 5As and the VT-100 is under half the cost of the Ref 600s alone! Since this discovery, we have achieved the same kind of unbelievable dynamics and seamless blending with ProAc loudspeakers and twin Vandersteen 2Wq 300 watt powered subs. So, if you want the sound of Ref 600s but cannot afford them, buy a pair of Model 5As or your favorite pair of ProAcs plus a couple of 2Wq subwoofers and mate them with a VT100 and you’ll get surprisingly close. You can cut the cost even further by running a pair of Vandersteen 2Wq 300-watt subwoofers with your existing speakers. Or mate a pair of 2Wqs with your favorite ProAc. In any case, it is the magic of SUBWOOFERS that allows this to happen. It is for all of the above reasons that there is only one subwoofer in existence capable of integrating seamlessly into a high-end music system, allowing you to reap all of the benefits of having a subwoofer, with none of the drawbacks. And the Vandersteen 2Wq is the one. And just in case you think I am a biased source, our correspondent Blaine Peck (who, for all you know is also a biased source) recently wrote the following, with no discussion between us about the topic prior to his sending us his comments. Whether reproducing the plucked string of an acoustic bass or the sound of an analog synthesizer, the Vandersteen 2Wq subwoofer is a seamless extension of any system. Nothing else need be added! With its internal 300-watt power amplifier, it is the perfect compliment to any sound system. Designed to take on the characteristics of your main stereo amplifier, the amp in the 2Wq will not sound foreign in your system. Also, through an extension of the Vandersteen design philosophy, a unique gradually sloping crossover system is implemented so you simply do not know where your main speakers stop and the 2Wq begins.

Now that your main speaker/amplifier combination need not concern themselves with those power demanding low frequencies, they are freed up to work in a more comfortable range. Yes, now what is coming from your main speakers will sound better than ever.

The 2Wq is not just another subwoofer. It consists of three 8″ floor-facing drivers, each with a massive motor. So why not a more typical single 12″ or 15″ design? Well frankly, the mass of a larger driver will not allow it to respond as quickly as the Vandersteen 8″ drivers to today’s demanding recordings. The 2Wq’s 8″ drivers are designed to handle the content but be “fleet of foot” at the same time. Concerned about where to put them? You need not worry. With the control of both its respective level and the “q” (how loose or tight the low end is) you have the flexibility to place them in a location that fits your living environment and not sacrifice performance. The simple beauty of this product will soon become an addition to your room.

So whether on orchestral music, hard rock or something in between, the Vandersteen 2Wq will exceed your expectations...."

@akg_ca -- nice and informative post.  Makes a ton of sense, and I've read nothing but glowing reviews of Vandy subs.  Don't know why I keep forgetting about them. 
Generally speaking, in a music system I agree Rel makes fine subwoofers and connection at speaker level make sense yet I would choose it as second best next to the Vandersteen Sub 3.

  Simply put they left out the most important thing the high pass that offers a better transition experience when properly adjusted.
 Vandersteen Sub 3 also hooks up at speaker level it offers a unique design high pass with analog room compensation correcting the rooms/ bass frequencies below 130 HZ with 11 independent left and right ch settings.
 It now features trickle down technology sharing the same exact concept tuning as Vandersteen 7,5, Quatro, Treo's or any speaker with Sub 3s as above. This unique adjustable 100 HZ or 80HZ high pass unloads the heavy lifting of your main amp allowing it to recover while the Sub 3s internal amp takes care of the lowest bass frequencies, This smoothing the lumps out of the critical bass response provides a far better foundation for ( Y o u r  particular  R o o m ) while dramatically improving the transparency and clarity of the whole system.
JohnnyR
Vandersteen dealer
Rythmik.. I like the L22 dual 12" driver sealed sub
http://www.rythmikaudio.com
akg_ca, Look up Dalquist DQ 1 This unit was brought out back in 1978 or so. A lot of what you say is correct. It is however not hard to make a much superior sub relative to what you can buy as long as you are using digital bass management and room control. There are many great drivers  and high powered commercial AB amps that will do the ultimate job. It all depends on your speakers, room size and length of the wall your system is on. You also have to have a shop to work in. There is no kit that I know of that attempts to be an ultimate design. !st is every woofer should have two drivers on opposite sides of the enclosure opposing each other thereby perfectly opposing and neutralizing newtonian forces. The perfect enclosure would be a sphere but very difficult to make in readily obtainable materials like MDF. Next would be a cylinder. This can be done rather easily. Just ask any Cooper if there are any still alive. I use 10 staves of 2" thick MDF and close it with strap clamps. You can change volume by changing diameter or length to get the right Q. The only commercial sub that can compete is the Magico.
I would not know how to spend 36K on a subwoofer. Each one of these subwoofers would cost around $1300. That is not including the amp and crossover, About $3500 soup to nuts and I use 4 subwoofers in a linear array so $14,000 for the system. With less expensive drivers you could do 4 units for $10,000
Two big things missing from the very long post above: the physics of rooms; and the hearing of humans.

The wavelengths at low bass frequencies are so long, much longer than any home sized room, that the bass has bounced around and been reflected off multiple surfaces long before the sub puts out even one wave. This fact of pure physics blows apart all the talk about imaging, locating bass, timing, etc.

Also every room has modal areas where bass frequencies reinforce. The modes move around depending on frequency and speaker location, one set of modes per speaker. Same with cancellation. Another fact of pure physics, it is simply impossible to attain really smooth low bass response in a room from just one sub. This has nothing to do with the sub! Its all to do with the physics of sound in a room.

This is a rather incontrovertible fact of physics. The solution is not a better sub. The solution is MORE subs. More subs results in more modes which results in smoother bass. Much smoother bass.

So "a" sub cannot provide really good smooth and responsive bass as a matter of physics. But won't more subs ruin imaging? Don't they have to be time-aligned, or integrated, or something??

Actually the fact is testing has proven hearing at low frequencies is so different from hearing at mid to high frequencies that not only can we not localize, we cannot even hear at all less than a full wavelength. Very low bass, 20 Hz, 20 times a second, each wave is 1/20th of a second. Anything lasting 1/30th, 1/50th, heck even 1/100th of a second at midrange or treble frequencies we would not only hear but instantly be able to localize. But a bass note that short we would not hear at all. They've tested with headphones. We do not hear it. At all.

So how in the world are we gonna localize it? We aren't. We get our location cues from higher frequencies. So the location of the sub does not matter. At least not with regard to imaging. 

Sure enough, setting up 4 subs I cannot hear any difference in localization wherever they are placed, or even any difference when they are run stereo or all mono. My bass is tight and tuneful and with instrumental sources localized with unbelievable precision regardless of where I put the subs or whether they are run in stereo or mono.

The situation with subs is so completely different than stereo speakers that for all practical purposes the question is not at all which sub. What matters is how many.  
^^ +1
The Audiokinesis Swarm is one of the best sub systems made. Single or dual sub systems can't deal with standing waves in the room and room treatment won't fix something like that. The Swarm is an elegant solution.
The mention of the Dahlquist DQ-LP1 by @mijostyn is timely. Mine is currently listed on Audiomart.
How much you asking for your Dahlquist DQ-LP please ?
“The Audiokinesis Swarm is one of the best sub systems made.”

A room full of 4 subwoofer boxes...do they come with cushions 😉

I see that Audiokinesis Swarm sub system often gets recommended, wouldn’t it be prudent to ask if the room can accommodate 4 subs before recommending such elaborate setup. Most people I know barely have room for 2 subs, let alone 4 subs. Just my two cents. 
My room is 3.5 metres wide by 8 metres long, thanks everyone for your input.
I’d add a few more questions... what are your main speakers and do you intend to run them full range and blend the sub in?  


What kind of music do you listen to and how loud in dB?


what are you looking for... a lot of punchy bass or just a sub to offset what the room eats up?


how much placement flexibility do you have?
lalitk
I see that Audiokinesis Swarm sub system often gets recommended, wouldn’t it be prudent to ask if the room can accommodate 4 subs before recommending such elaborate setup. Most people I know barely have room for 2 subs, let alone 4 subs. Just my two cents.

You bring up a good point. This is just one of the reasons most of us go the extra mile and instead of saying Swarm usually say Swarm-type or distributed bass array or some such. Trying over and over again to get the point across that its not the size or type but the number of subs that matters most.

Now I'm winging it here so don't quote me I'm just trying to get an admittedly hard concept across as best I can. The four 10" speakers in my distributed bass array, to get that from one sub would probably require a Sub-Zero size speaker. Even then it would only be as powerful, but not as smooth. My four together are a lot smaller.

So if space is a concern probably four 8" or even 6" or maybe even smaller subs would deliver much better bass than the one REL or Vandersteen that is everyone's preconditioned knee-jerk response. You could in other words buy four Hsu subs made for car audio, lay them out under and behind furniture, and have much better bass than you could ever get from the one everyone who doesn't understand the physics recommends.




@select-hifi, my DQ-LP1 is listed at $399 plus shipping. 100% factory stock in excellent condition, with original shipping carton w/packing materials and instruction sheets.
A REL Studio III for only £1000? I’ll take 2 please!

Thats about what it’s smaller brother, the Stentor sells for, currently. I’ve been looking for a Studio or a pair of them for some time. I would jump on that deal in a second.

From on the Stadium to the Stentor and the Studio, I think those were REL’s best offerings, in my opinion.

Edit: Is it a version III or II or I?
REL Studio mk11(2) I can also purchase REL Studio mk1, both subs have XLR high level input, which is my preferred way to integrate into system, Studio mk11(2) has RCA input as well which I will not use, I think your right the REL Studio at £1000 is definitely the way to go.
I will add to the list, the JL Audio Fathom F-113. I own 4.

ozzy
I agree with John Rutan's recommendation of the Vandersteen Sub 3. While all Vandy subs are musical, the high pass filter he refers to is key. When you relieve your main amp of mid to deep bass duty, your system will sound much better thru the mids and highs too. The Sub 3's eleven band EQ. is icing on the cake as you can do a lot to correct standing waves and room nodes in the bass frequencies. You can get great sound using just one of these subs if you want. Two will obviously improve. IMO.

I see that Audiokinesis Swarm sub system often gets recommended, wouldn’t it be prudent to ask if the room can accommodate 4 subs before recommending such elaborate setup. Most people I know barely have room for 2 subs, let alone 4 subs. Just my two cents.
The thing is, the actual boxes are rather small as subs go. I've only ever seen them in smaller rooms where usually getting the bass right is out of the question. Obviously two go near the front speakers, so no worries there- the other two are placed at asymmetrical locations and due to their small size often can fit under coffee tables and the like. When I first experienced the Swarm I couldn't even tell where two of the subs were- they weren't visible.


IOW the Swarm solves the problem of putting a sub in a small room; 23" tall by 12" wide by 12" deep. As subs go that's just little.


Of course all of this is at http://www.audiokinesis.com/the-swarm-subwoofer-system-1.htm
Start with a used single REL and get another one later...I did this and although both were luckily very inexpensive as I shopped around for a while to find nice ones (for 200 bucks each!), they're amazing sounding things and work together to make the room sound great...a Swarm seems like a great design but the cost and perhaps not having room for 4 subs and the wiring for them might be prohibitive.
Rythmik’s 15” and larger are likely the best musical subs for the money. By that I do mean bang for buck, maybe a $30,000 sub from another company is better, but the Rythmik E15 has little competition in its price bracket. 
 
Especially if you are looking for full-range (REL’s flagship doesn’t go as low as Rythmik’s cheapest sub).  
  
Rythmiks sealed servo subs are awfully tempting at their price point. Can get 4 and make a swarm, too!

Although I would probably say that if I could get 2 used Vandy 2wqs for under 1k total (including x-over) that would probably tip me over the edge in its favor.
@bstatmeister, the Rythmik L12 can be had for $539 shipped, and Brian Ding offers a 10% discount for multiples. Under $2k for a swarm of Servo-Feedback Rythmiks!
Four separate self-powered subs means being able to set four individual crossover points, four individual levels, and (if they have this option) four individual phase settings. That would totally be the way to go!

 
Every single Rythmik sub, even the lower-priced models, contains a continuously-variable phase control on a rotary knob, not the 0-180 phase switch found on most subs. It provides ANY amount of phase/time delay from 0 to 6ms, equivalent to moving the physical location of the sub from zero to about six feet. Essential to dialing in a sub for maximum performance/sound.
I run my main full range with a pair of rel Gibraltar 2s for listening to music. 
What AK says about using 4 subs makes sense on paper.  For most, they can't put those subs in a room.  Even if you do, you still need to put them where they sound best in the room and it's hard to do if it's not a dedicated room.  

IF you get better subs than the AK's, you can do the same 4 unit set up adn get better sound.  I LOVE what Vandersteen does with his Sub 3's (all his subs) using the analog EQ (no digital nasties).  What I've found using his subs are the best in room bass I've ever experienced in my house.
I've not experienced any subs that can compete with the REL 212 SEs
Best,
Jim Smith
@hornguys --

I've not experienced any subs that can compete with the REL 212 SEs
Best,
Jim Smith

I've not heard any subs that can compete with horn subs (Tapped Horns or Front Loaded Horns). Few know of them and their sound, sadly..
ctsooner
What AK says about using 4 subs makes sense on paper.  For most, they can't put those subs in a room.  Even if you do, you still need to put them where they sound best in the room and it's hard to do if it's not a dedicated room. 


Oh, its not just on paper. If you bother to check it out you will learn Duke spent many years building, testing and comparing virtually every speaker design known to man. I think large horns were the only ones he didn't try. The distributed bass array design makes total sense on paper, but even then, if you bother to read about it, it is based on extensive measurement and testing. It doesn't only make sense on paper. It makes sense in the real world. Because it IS the real world!

What's especially ironic about this is, its the conventional subs with their measured anechoic chamber response that bears no resemblance to any room they will ever be used in that everyone thinks is real, while the exhaustively tested in actual real world sized rooms DBA is derided as "on paper."

The same speaker placement that is so critical with only one or two subs becomes almost trivial by comparison with four. One has to be moved around, and around, and around, as you struggle to find the least bad combination of resonances. With four the resonances are smoothed out by number instead of location. You can pretty much plop them down wherever they fit. Which being smaller than all the other subs people are talking about is a lot of places.

Its convenient to think about stuff. Anyone can make up whatever reasons and come to whatever conclusions they want. In your own mind you always win! Reality is never quite the same. Try it and see.
The same speaker placement that is so critical with only one or two subs becomes almost trivial by comparison with four.
^^ This.
I just replaced two Paradigm reference 15 subs with two Rel Carbon Limited subs (12") for two channel music.  Big improvement in everything; subtle, smooth, less boomy, yet deep and warm and the entire soundstage improved.  As they say, very musical.  I have a large room and you now feel and sense the bass without being overwhelmed.  Very easy to hook up with the Longbow Wireless, so once connected the positions can be tweaked without regard to cables.  And the Longbow wireless transmitters sit behind a wooden cabinet door without issues.
I also considered the S-5's and am sure they would have done the job, but oh my the Carbon Limited's are sweet!
The T series do not have they same Longbow system.  I was skeptical 
about the wireless, as it seemed just another thing to go wrong, but after speaking with some dealers, they highly recommended the Longbow.
Purchase the most powerful REL your budget allows. Their Neutrik Hi-Level connection directly to your amplifier provides the most seamless and accurate integration available. Yes, now made in China and while there are some substandard factories in China, there are some really good ones with good QC. I have the S/5 SHO connected to my Krell Class A amp and it rocks! 
“I also considered the S-5's and am sure they would have done the job, but oh my the Carbon Limited's are sweet!”

I own a pair of Carbon Limited as well and they are pretty amazing. I mostly listen to jazz but other day, i cued up ‘Why so serious?’ from Dark Knight soundtrack and they rocked my dedicated room -  15’D x 30’W. 
I hate to say this and I really do not want to pop anyone's balloon but the only really accurate subs  commercially available are the Magicos.
Put on some punchy music. Walk over to your sub and put your hand on top of it. Any vibration or movement you feel is distortion. The Magicos do not vibrate at all. Nothing. It is like they are not even on. Now, they are overkill to the max. You can produce the same results in a much less expensive manner. But you can't make sub woofer at a cost. Good subs by nature have to be very heavy mandating high shipping costs and associated problems for the end user like a lumbar strain. The only other subs that I have seen that did not vibrate were home made. I know one person who had a local cabinet maker do it for him.
Now I am all for multiple subs. I use 4 myself. There are issues with the swarm method that prevent them from being near as powerful as a linear array properly set up. When you are placing subs in a room in an asymmetrical fashion you are distributing the standing waves and comb filtering so that the system response is more even through the room which is wonderful. The are several problem. First is you are stuck using a very low crossover point. If you go up too high you mess up your systems imaging. With Dipole planar speakers the best place to cross is around 125 Hz. The effect of cleaning up the dipoles is dramatic. This is too high for a swarm system. Second, unless you are in a really small room in a swarm system the subs are acting as individual point source loudspeakers. Point source speakers do not project acoustic power as well as linear arrays do, not even close. Positioning a linear array correctly eliminates most of the primary reflections that cause erratic volume changes throughout the room. You get the same result as the swarm but in a much more potent fashion. If you have four subs spaced across a 16 ft wall at a little over 5 foot intervals with the two outside units is the corners what you have essentially is a 16 foot woofer. If the drivers are closer than 1/2 the wavelength of the highest frequency you want to reproduce the drivers act acoustically as a single drive. You see this in any dynamic liner array speaker like the Carver. Remember the Pipe Dreams? All tall dipoles like Maggies and Soundlabs are linear arrays. 
If you put just two subs with these speakers the low end will disappear as you move away from these speakers. You can use two subs with point source speakers and certainly a swarm if you keep the crossover below 80hz but a swarm set up will not work well with tall dipoles. A lot of people think dipoles do not go loud. You take the bottom 125Hz away from them and they go seriously loud. My Acoustats hit 115 db and I'm sure Soundlabs will go even louder. Maggies will go loud too but they are limited by the fragility of their tweeters which are in danger of popping over 100 db. 95 db is a comfortably loud volume. I only go louder when I am listening to the Pixies.
Oh and millercarbon if you start out with a crappy sub I do not care how many you have and where you place them what you are going to get is crappy bass.
I agree with mijostyn.  As for me saying 'on paper', I was just pointing out he has a white paper on it.  I agreed with what he come up with, but I also know that his actual subs are not at the same quality as most if not all the subs we are discussing here.  

I have heard the Vandy subs in a 4 array and with the EQ, it's even easier to dial things in.  Bottom line is that there are some very good options.  In my room, I can't/won't fit 4 subs as I don't have the room.  I had no problem setting up my active subs using the EQ and a Radio Shack meter.  

Others swear by the REL or other subs.  The biggest thing is trying to integrate them into the main speakers. 

Also, you mentioned 'real world' and I agree. Vandersteen also voices his speakers in his living room, because it's a real world situation.  
@millercarbon
i gotta say, after trying millercarbon advice to put my unused jbl lsr 305 pointed into the corners of my listening room, i think a swarm subwoofer setup is the way to go... i decreased the volume on my roaring beastly jbl lsr 305 sub and re-shelved it to 80Hz from the 120Hz setup I used previously. sounds really smooth and engaging... Led Zeppelin and Melvins really rawks...
canibefrank
@millercarbon
i gotta say, after trying millercarbon advice to put my unused jbl lsr 305 pointed into the corners of my listening room, i think a swarm subwoofer setup is the way to go... i decreased the volume on my roaring beastly jbl lsr 305 sub and re-shelved it to 80Hz from the 120Hz setup I used previously. sounds really smooth and engaging... Led Zeppelin and Melvins really rawks...

"Yeah! Science!"


mijostyn
Oh and millercarbon if you start out with a crappy sub I do not care how many you have and where you place them what you are going to get is crappy bass.


See above. I guess those JBL 2-ways must be really good subs. Either that or someone doesn't know what they're talking about. LMFAO!

@ctsooner wrote: "What AK says about using 4 subs makes sense on paper."

And later, ctsooner wrote:

"As for me saying ’on paper’, I was just pointing out he has a white paper on it. I agreed with what he come up with, but I also know that his actual subs are not at the same quality as most if not all the subs we are discussing here."

Please tell me how you "know" that my "actual subs are not at the same quality as most if not all of the subs we are discussing here."

We can have a difference of opinion, that happens all the time. But you just slammed my product, so I’m challenging you to back that up with specifics. Whatever your reasons for making that statement may be, I think it would be fair for you to give me a chance to respond to them.

Thanks.

Duke

As I stated, I agree with your principle about using 4 subs.  
I didn't feel I was slamming you at all.  What I was looking at are subs that cost more than yours after looking online to see prices, so that's probably not fair.  I have heard your system a few years back and liked it a lot, but I do feel that the Vandy sub 3 or the REL are using better quality drivers and internal components.  You will pay more of course, but that's my perception based on what I have seen and heard over the years.  

I'm sorry if you take that as slamming your product, but it's not what I'm trying to do.  For the price, it's a very good value and I've even stated that to friends and on other forums.  
Thanks Pete

@ctsooner wrote:

"...I do feel that the Vandy sub 3 or the REL are using better quality drivers and internal components."

You now say your "feel" this. In your post that I objected to above, you said you "know" that my subs "are not at the same quality as most if not all of the subs we are discussing here."

Which is it? "Feel" or "know"?

The 10" woofers I use have exceptionally powerful motors. The combined motor strength of the four woofers I use in a Swarm system is greater than any single home audio subwoofer motor I am aware of, including the sadly discountinued TC Sounds and Acoupower woofers. It is only surpassed by one production prosound woofer that I am aware of, the 1-ohm B&C 21IPAL woofer. Are you aware of any three grand subwoofer system that is anywhere near this ballpark as far as motor strength?

My woofers also have over twice as much thermal power handling as they would need in normal use, and nearly four times the mechanical power handling they would need in normal use, "normal" being, the amplifier driven to its maximum output.

Now it’s your turn. I invite you to be specific.  You said you KNOW.  Please tell me what you KNOW.   And if you DON'T KNOW, kindly make that clear.

Thank you.

Duke

I believe that REL's HQ is located in Wales, UK. There is a division in Berkeley CA/USA for some R&D and servicing of older models, or so I was told a few years ago when I had one serviced there.

On the website they have a speaker pairing page to help determine which model is the best fit. 

https://rel.net/speaker-pairing/  

The Neutrik High Level Connector is definitely the way to go.
There are cable company's that build a better connector cable than the stock or REL Bass-line Blue cables. Source them on the used market.

https://www.analysis-plus.com/product/home-audio/interconnects/rel-subwoofer-cable/
 
https://www.synergisticresearch.com/

I fell into a pair of REL B2s - (10 inch drivers / 300W amp)  two days apart on the used market, same color. Six months later took a pair of Tesla Le REL from Synergistic Research, also on the used market. Brought the experience to a another level. 

Good Luck