Interesting. I did two measurements @96000, first with a tone sweep, and then with white noise. The results were: Tone sweep: www.geminiflux.com/Stuff/snapshot1.png White noise: www.geminiflux.com/Stuff/snapshot2.png The card being use was Echo Mona Laptop, the microphone a Shure Beta58 (which might account for the weird behaviour), and the speakers were Mackie HR824. I'll give it a try next week with a better microphone. Cheers, Andres Jon B wrote: >I realized why they do this. With variable sampling frequencies, >44.1, 48, 96, you would need different filters to get the best out of >each one. So they just do 20 once and throw away the extra bandwidth. > So does that mean they will alias at sampling rates like 11025? This >could be tested, too.