Hello, brand new here and to HT as well. I bought an HK AVR 340 last month (open box at Circuit City $390). Got it hooked up pretty easily and ran the auto setup fine. The thing sounds great, but you have to turn it up about -10 to have it at a good movie volume. The room we have it in is 18 feet deep and 15 feet wide , with vaulted ceilings. After reading thru some of the postings here, I am considering adding an amp to the system. My first question would be ,if I get a 2 channel amp and hook it up to the pre-outs on the front left and right, does the receiver adjust and send the power its not using on the fronts now to the center and surrounds? Or do i need to get a 7 channel amp?