(poor-man's version of bbarden's system...)

Mains - Vandersteen 2ce's set to large
Center - Vandersteen VCC at 120Hz
Side Surrounds - Vand. VSM-1's at 80Hz
Rear Surrounds - Small, old, Plastic POC JBL Surround-1's at 80Hz (ideally should be higher, but a quad-crossover's asking a little much)
Sub - SVS 16-46 CS (passive sub) powered by a Nakamichi PA-5

Since I don't have a whole lot of power for the sub and the mains are bi-amped, I figured setting the mains to large would give me the potential for more power, since 3 amp channels are providing low bass instead of just one. It sounds to me like the theory works, plus the Vandy's are tighter/more musical than the SVS.