Comparison of various subwoofers for 2 channel audio

I run the Audiokinesis distributed bass array. I found this article, recommended by Duke LeJeune, to be helpful for placement of multiple subs.  Tried to post a link but it kept including the entire 30 page pdf.  
 

So Duck Duck Go cut and paste:

"Subwoofers: Optimum Number
and Locations" by
Todd Welti 

@carlsbad2 wrote:

One thing i've noticed with subwoofers.  there are two types of listeners:  those adding subs just to make the bass natural--the way it was recorded.  And then there are those who want more bass than is recorded on the track.  I'm not criticizing anyone but these discussions go sideways as the two different crowds have 2 different answers.  It is good to define which you are.

Due to the nature of bass distribution acoustically in domestic environments I'm guessing quite a few are missing out on what naturally present bass can really sound and feel like, as an uneven and less clean reproduction of the lower octaves is typically gained back to not be felt too conspicuous one way or the other in the overall mix. Making matters worse in the context of subs is poor integration with the mains that will only exacerbate the issue of lowered gain. That being the case there's often a lack of proper foundation in music playback without people really knowing about it, because the issues seem to have been dialed back - but with them the sense of natural presence and fullness of bass as well. 

So, I'd argue that what many feel is a natural bass as found in the recording is really not a true indication of such, but rather a more or less anemic version of it. Don't get me wrong; subs dialed too loud with frequency irregularities/boominess, feeling like they're making an effort, marred by overhang and not properly integrated are a nuisance of which one is better off without. However, while the former scenario is less intrusive it's also, potentially, not enough of a presence to be felt truly natural as heard in live music - acoustically or amplified. 

The lowest octaves require the most energy to be felt "linear," clean and natural, and for that one needs much more displacement that may at first be anticipated, in addition to efficiency and/or a lot of power. Seeing subs of typically smaller size than the main speakers, even significantly so, is the first indication of something gone wrong here, but try and get that through to audiophiles who'll mostly laugh at the sight of large and/or stacked sub towers per channel claiming that it's way "overkill." What it really is however is exactly what's needed: "overkill" is simply common sense where the lowest octaves goes, as this is a way to ensure proper energy, ease and physicality of reproduction. 

I'm definitely an advocate of natural bass, but for that there's no way around the adherence to physics with all that implies, as well of course overall integration. 

@tcutter 

From what ai deduce from a cursory reading of that recommended presentation is that 4 subwoofers are best for most rectangular rooms, in most situations.  Interesting.  Thanks for sharing.

@drbond i recommend searching the forum for ‘swarm’ to find threads on swarm distributed subwoofer array. 

Another vote for REL and also to swarm subs. 

REL subs are truly tuned differently...they seem to add a lot of space and air to the signal and aren't just about thump.  They are also very fast. 

Swarming has helped eliminate bass nodes.