Do you have any sound "enhancements" such as Reverb, Chorus, etc turned on? That would cause it to sound "hollow", etc. I had a SoundBlaster installed and remember a panel with all those items in it. Don't remember how to access it.
I didn't have any PC sound problems with my SoundBlaster Xfi, but I had to remove it as it was interferring with my Sonar recording program and my regular recording interface unit. I'm now using an HT Omega "Striker 7.1" (PCI) sound card and it does not interfere with my recording studio software.