I've thought on this a lot recently. My altima came with stock speakers that produced a lot of bass and were very clear. People kept asking me what kind of sub I was running. When i switched to my pc, all that bass went away. the sound was slightly less clear, but that never bothered me. Boosting the bass thru software didn't seem to help at all. I think that because I'm using the onboard sound I'm not getting as much bass as I used to. I'm concidering purchasing one of the expensive sound cards with the little knob connecter things that I'll fab into the console.
Has anyone else experienced a drop in base with onboard sound processor? Did a better card fix this?