Hello, I recently purchased a Sony BDP-350 Blu-ray player, that I have hooked up via HDMI to a Sony STR-910 receiver. When I play either blu-ray or DVD's in 5.1 I notice my subwoofer almost has no volume to it. When I switch to dolby 2ch it has lots of bass. I didn't think there would be such a drop in bass when going to 2ch to 5.1. I watch a lot of music concerts where I would like for some bass to come through, but it seems like it barely even there. Any suggestions as to why this is happening?