If you go 7.1, the side surrounds should be close to parallel with your main seating area, then the rear surrounds go behind you and tilt inward on a 150 degree angle.


Take a look at the dts setup. If you cannot do this setup, then it will mess with your brain.

Having said that, i went 7.1 years back and have really enjoyed the added ambiance and effects especially from 7.1 Logic7 music mode. Plus, most HD channels are 5.1, but your AVR will add the extra 2 channels which is sweet. So, if you show is DD, then the AVR will go DD EX, etc.

Side Note: I don't aim the rear speakers downward at all...you want the rears to be less-localized as possible.