Comparison of various subwoofers for 2 channel audio


I have a 2 channel audio system, and I appreciate how subwoofers have augmented the sound quality of my system (with electrostatic speakers).  I currently am using a pair of Martin Logan Balanced Force 212 subwoofers, but I’m thinking about adding more subwoofers for a total of four in order to help balance the low frequency sound waves.  I’m considering adding a pair of Rythmik, SVS, or perhaps Velodyne subwoofers to the system.  Does anyone have experience with many of those brands, and how well they integrate with electrostatic speakers in a 2 channel system, or perhaps should I just get a second pair custom built with certain specifications?  
Thanks.

drbond

I test drove all the major contenders and pretenders.

best I’ve heard : ATC 

Here’s the one I bought for my 2-channel “A” system. Highly recommended 

ATC C1 Sub Mk2

Under that real wood veneer, there's a hand-built, 12-inch ATC bass driver and 3-inch ribbon voice-coil – which is hand pressed and assembled. 
and you'll also get ATC’s standard six-year warranty

 

After 30+ years dealing with so many Hi End subwoofers, I was finally able to rest utilizing 6 JL Audio Fathom 110 subwoofers stacked 3 to the left speaker and 3 to the right speaker.  Each speaker is specifically turned to a certain frequency so that the bass sounds natural and complements the speakers. I had plenty of help setting it up from the JL Audio factory team.  They understood what I was trying to accomplish.  Thanks JL Audio 😊

My single RSL 12S replaced a pair of well known subs, and it is an awesome match up with my Lascalas.

@decathlon1991 

That sounds like a rather unique solution:  3 high on each side!  One of many possible solutions, as the next post by @mrdecibel went from 2 subs to 1.  

It's great to hear the variety of approaches hear to 2 channel music.  I think I'm going to go with 4 dual opposed subwoofers, with the first 2 placed in a slightly staggered fashion just to the inside of the left and right speakers. 

 

I think I’m going to go with 4 dual opposed subwoofers, with the first 2 placed in a slightly staggered fashion just to the inside of the left and right speakers.

The easiest/most effective first shot may be to just place them in all four corners if possible as this is probably less likely to produce peaks/nulls. Better yet, put them at the midpoint against each of the four walls as that is supposedly optimal placement — that’s what I’ve heard from an expert anyway, and it’s free to try of course. FWIW.