its not your sound card that was causing poor sound quality, but the headset.
since it's usb, it bypasses your sound card when you plug it in, essentially acting as its own sound card. no matter what sound card you have, the headset will sound the same. find a headset with normal 1/8" plugs to make use of your sound card.
if its not plugged into the soundcard, its not using the soundcard.
Intel E8400 @ 3.78ghz
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ASrock P43Twins1600 (hates RAM dividers)
WD Caviar 500gb + 250gb hdd, 32mb cache
eVGA 7900gs @ 585/1700mhz
OCZ GameXStream 600w PSU
Sound Blaster X-Fi Platinum
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