Bi-Amp Woofers with Class D?

Works good.

My speakers are full range to 20Hz but because there are standing waves in the room, no bass at the listening chair. I installed 2 extra subs, asymmetrically placed in the room, to break up the standing waves. They are driven by a class D amp that is rolled off above 60Hz. Now the bass at the listening position is correct like it is elsewhere in the room.

class D offers tons of power for not a lot of space and not a lot of dollars. 
pretty good for freq below 80 hz. And if you buy a class D amp to drive your woofers, go get a big one, not something intermediate....

what is the configuration of your speakers? 

Avanti,
Wish I could post a picture. I use an equilateral triangle arrangement overall.
The speakers in the FSMs consist of a 15" coaxial and a 15"woofer
in each unit. 
Is this your question?

Atma,
I am starting to think that rather than bi-amping I should consider
buying two REL T7 powered subs.

Any thoughts on that?

I am starting to think that rather than bi-amping I should consider
buying two REL T7 powered subs.

I don't bi-amp; my front speakers go flat down to 20Hz. I use the two subs to break up the standing waves in the room.