I finally got my 5.1 surround setup going consisting of a Denon AVR-3805 receiver, an Outlaw 7100 7-channel amplifier, LSi15 fronts, LSiC center, two LSi7 rears, and PSW650 subwoofer. This setup sounds great with movies in Dolby Digital -- lots of powerful sound and clean bass. However, when I listen to music, the bass seemingly all goes away and the sound is just average.
To listen to music, I connect an optical cable from the optical out on the breakout box of my Sound Blaster Audigy2 ZS Platinum Pro sound card to the back of the receiver. The vast majority of my music is in MP3 format encoded with LAME at bit rates around 300-400, so I don't think the problem is related to poor quality MP3s. On the receiver, I set it to "Pure Direct Mode" which the instruction manual indicates is the best for two-channel audio. It sounds decent, but I'm certainly not blown away by it, and the bass is really lacking. I also have to turn up the receiver up above negative numbers to get sufficient volume, even though the volume on my sound card is turned up fairly loud. This volume level would blow me out of the room if I kept it for DVD or TV. Does anyone have any suggestions? Thanks.