I agree, I think your problem is your onboard sound card. I would recommend picking up and outboard soundcard, the quality differences are huge. I realized this when I was checking my onboard cards with REW and then purchased an outboard card and checked it, the stock boards had terrible readings, mostly just 70hz up to about 3000hz. the Creative Labs external card I bought has a flat response from 0 to 25000hz.


Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70