Onboard Audio Quality
We used Asus’ acclaimed Xonar D2X as an audio capture device to test each motherboard’s onboard audio quality under RightMark Audio Analyzer 6. Because the graphing function of RMAA6 supports a maximum of four products, we organized these alphabetically.
Asus provides the best frequency response, with Gigabyte only slightly behind. The curve drops off at around 18 kilohertz for all models, some more drastically than others, with only the P5Q Deluxe reaching 20 kHz within one decibel of the output signal.
ASRock’s P45TS-R looks a little better than average noise level, but the average is so good we really can’t fault any of today’s test samples.
All of today’s motherboards showed good dynamic range, with Jetway’s HI04 only slightly behind the overall average.
Total Harmonic Distortion
All of today’s samples also showed very little harmonic distortion, except for some odd spikes in Biostar’s TPower i45 graph
Most of today’s samples had good stereo signal separation, but Asus’ new AD2000BX codec appears to have a slight problem. We hope this problem can be corrected with a driver update, but casual listeners probably won’t notice it.