Asus - Realtek ALC882M 7.1
Foxconn - Realtek ALC882M 7.1: In comparison to the other three candidates, Foxconn's audio subsystem is the least impressive.
Intel - Sigmatel STAC922105. Quality-wise, Intel's sound system is clearly the best.
MSI - Realtek ALC882M 7.1. MSI does well: Overall, the 975X Platinum Power Up Edition is second best.
Audio test ranking:
1. Intel D975XBX
2. MSI 975X Platinum Power Up Edition
3. ASUS P5WDH Deluxe
4. Foxconn 975X7AB-8EKRS2H