I've tested the speakers through the control center and all the speakers play a sound individually. I then tested them through Windows 7 sound panel and all the speakers play the sound individually. Now, the issue I'm having is when I it set to Stereo, PLII Movie, PLII Music, only FL plays; Stereo x2, RL plays; 6 channel direct, RR plays. The input is Direct. I purchased these speakers used, so I have no directions. How do I fix this?