Need some advice, just to clarify matters on amps/receivers. If I have 6.1 receiver, and I add 2 mid-rear centres for EX/ES does the receiver seperate the audio coming from both speakers or would I need a 7.1 receiver for this scenario? Also what is bi-wiring and how does it work? I keep getting conflicting advice on this and would I need it for the above set-up? And when do I add a power amp into my system? At what stage would I think I need to buy one of these and what advantages would it have over my current amplifier/receiver? I know a few of these questions are probably very basic knowledge, but when I keep getting conflicting answers it doesn't end up so basic!!