asus mobo, poor sound quality

[Timothy Smith]

hi i have an asus p4s800-mx with an onboard adi 1888 audio, i load it 
with kldload snd_driver, loads fine, here is the output of the sound device

%cat /dev/sndstat
FreeBSD Audio Driver (newpcm)
Installed devices:
pcm0: <SiS 7012> at io 0x9400, 0x9000 irq 18 bufsz 16384 kld snd_ich 
(1p/1r/0v channels duplex default)

it works alright, but the sound quality is really bad, crackly and 
muffled bass. i know it's not my speakers or my setup because it works 
perfectly on my windows system which sits right beside the bsd system. 
it is definately the freebsd driver.

so, is there some way i can fix this or is freebsd totally gimped with 
this chip? it's supposed to be ac97 compatable.

thanks in advance