Originally Posted by Rod Gervais ➡️

That soundcard is (roughly) +/- .1dB from 30Hz up to around 20kHz..... and above and below those (so 20Hz to 24kHz is only off by (again roughly seeing as the graph is not accurate below +/- 1dB) +.1 to-.3dB max. IMHO a 1/3dB variance is a non issue..

I would not bother calibrating a card that was that close to being spot on.

The huge dip beyond 24kHz is meaningless, as is the drop off below 20Hz for the purpose of analyzing a small control room for treatments.

Rod