Soundcard noise level


2010-04-09 10:07 am
hello there.. this is the first time i create a thread here.. please forgive me if i've done anything wrong.. :eek:

i've tested my Creative Sound Blaster X-Fi Surround 5.1 usb soundcard with RMAA and got the result of noise level as attached..

my question is why is the noise increases towards lower freq starting from 300Hz? :confused::confused: who's the culprit?