Home theatre application. Room is roughly square, 20'x20' with a 10' ceiling, and opens into a common area of about 600 square feet with the same 10' ceiling.

Existing speakers are Vandersteens (2ci's) driven with far too much amp, but that's a different story. The 2Ci's are great for music but the variety of digital sound effects in Lord of the Rings and other contemporary DVD's are driving them batty on the low end. You know what I mean.

So...it's time for a sub. Or subs. I've done a lot of research in the ~$1.5K range...there's plenty out there...obviously a pair of LFM's is on the short list.

I've got the amperage to support a couple of 525 watt BASH amp units. I have the space and spousal sanction for placement. What I'm concerned about is my choice of two 25Hz units vice say, a single larger 20Hz or less unit such as an SVS or Axiom. And SPL. I like to feel my movies.

Has anyone here any experience with one LFM in a space of 4000 cubic feet open into an even larger room? Or two LFMs?

And, is -2db@25Hz sufficient for the truly extraordinary deep work, particularly in such a relatively large area?

Thanks!