Hi. I have setup two front speakers, center speaker, subwoofer, and two rear speakers. The confirmation sound came out of each speaker, but when I play something, no sound comes out of the center or the rear speakers. When I switch them in back of the amp they play, but are silent when hooked up where they should be. A friend mentioned that I’m in stereo mode and I need to be in stereo 5.1. A little advice would be appreciated. Thanks