STR-DH800 A/V Receiver 7.1 system I have the above receiver and I'm having issues getting A+B speakers to output the same volume. B seems to be the main output and when I select both A+B "A" sound is very low and faint. I'm playing music and not any movies. I'm not too sure if it's designed this way or not. I would like equal sound level volume coming from all 4 speakers I have. Can anyone help ?