Okay, I'm not an electrician! However, I do not see any potential problems connecting the 7th channel. The 950 will not be sending anything to it if you configured it correctly. I had my system all connected for over a month before I ever connected a pair of speakers for the two rear channels, I just had it configured for 5.1. When I set up the rear speakers I just re-configured the 950 to a 7.1 set up and like magic it came to life. You should have no problems.