Will a sound card help?

if my usb headset (steelseries siberia v2) has it's own sound card, will my computer's sound card be used at all?

i'm trying to decide whether or not to get an xonar dx

No, your computer's sound card is not being used. The USB is just passing the digital information to your headset's soundcard which then converts the sound into analog. Unless you want to buy a regular headset or use speakers then there will be no difference.

ok, that saves me about $80 there, now i can get the extreme9 mobo, with it's built-in wifi

Remember to post in this section next time. The other one is reserved for archives from the previous sites since the beginning.

oh, i though I was posting in the other one.... maybe rename it to archive?

It will not use the sound card, but a dedicated sound card will have way better sound production then a usb one.