So how many people are using subwoofers

to add to the excellent subs already mentioned here (Rythmik, SVS, Audiokinesis, etc) i will also suggest Seaton Sound.  i recently added a seaton submersive f2 and am EXTREMELY impressed with it's performance for music (for movies, a distant second consideration for me, it's staggeringly good).  for reference, i've also owned subs from JL Audio, Vandersteen and SVS and prefer the seaton sub to all others.

The Swarm system just seems cool and inexpensive…if I wasn't happy with my RELs I'd seriously consider those things. It's true that a lot of music doesn't get to sub territory, but I like the ambient aspect of the sub adding that airy reality to the mix a much as the direct bass reproduction...systems need that to seem more like natural sound.

I like the REL a lot, but you should also look at the Hsu brand - I use a couple for cinema use only and they meld well and are quite tunable, depending on which model you get.  I do use them for music play back with organ - my main speakers are 3db down at 20 Hz while the Hsu go down to 16 Hz (what you need to reproduce a 32' organ stop, which you feel rather than hear)

I agree Wolf.  I wonder how many have not purchased them because they are not priced high enough.  I paid about that for my one SW-12, used.
dc, you say,

"I can vouch for REG's observations.  It KILLS my single V2W"

What is your context?  Did you hear REG's set-up, or have you tried them in your own system? I haven't heard much from owners but I am curious.  

I am a big fan of having sub woofers.  Having said that, I find that it takes a lot of patience to get them "dialed in" to the room and the side speakers.

A few months ago I upgraded from a pair of two-way monitors to a pair of three-way floor standing speakers whose specs indicate bass as low as 37hz.  It took a while, but when I got the floor standers in just the right spot, they sound great, but don't really produce that last octave of bass.

I ordered a pair of JL Audio F113V2 sub woofers, really great subs, but they brought out all sorts of problems with the room.  I have installed six bass traps, and have two more on order, and am on my way getting the boominess out of the room, but it's been a struggle.

My former system was in a much smaller living room, took some time to get the sub dialed in, but once I did, it put a wide grin on my face!

For me, I really enjoy having that last octave of the musical spectrum, so it's been worth the investment of time, patience and money.