Originally Posted by kemetblk
thanks to everyone for the replys! i decided to go with the A9's and the CSi A6, a little more than i wanted to spend after shipping ($813) but i trust the advice on these boards.
now i'm just worried about powering them. i have a SVS PB12-NSD so i plan on crossing them over at 60hz. i'm worried that my SR6006 wont be able to push them properly and was wondering would bi-amping help or hurt? also, any recommendations on a decent amp, preferably less than $350?
Passive bi-amping (without using an active crossover) has very little benefit. You'd probably have more success by crossing your speakers at 80hz, and letting the sub do the heavy lifting. Most of the power consumed by speakers is used in the lower frequencies, so the more of that you push to the sub, the less your AVR will have to put out. 80hz is the THX recommended crossover, BTW.
As to a seperate amp, you will probably need to increase the budget a bit. You can get a Emotiva XPA-3, which is 200wpc into 3 channels for a bit over $600 right now. The Marantz Sr-6006 puts out about 70 wpc into 5 channels at 8 ohms, so to really see a difference, you need to look at a big amp, and, even then, you will probably only notice a difference at higher volumes.