Hello everyone. This is my first post, though I've been reading on here for months. Anyway, I'm using a Denon 3802 receiver with a Denon poa 5200 amp for my front towers. The 3802 is rated at 110 watts x 7 channels, and the 5200 amp is rated at 120 watts x 2. Do I need to calibrate my system to take in account for the extra wattage of the 5200? I have video essentials, but I never went so far as buying the meter from radio shack. Any help would be appreciated. Another question...the 3802 has 3 crossover settings...80, 100, 120....Should I leave it at 80? (80 is the default setting). I read somewhere that THX uses 80, not sure though. What exactly does the crossover setting do? Thanks guys.