> One problem with simple interpolation is that it introduces high frequency > noise, so it has to be followed by a low-pass filter. I haven't looked at > the code, but if you haven't done that, it would explain the poor quality. Yes, but looking at the available menu in mixer preference, I feel it would be silly to do interpolation with a low-pass filter, as it would mean more processing than the lanczos implementation (which does both in one operation). > > A quick look at Wikipedia suggests that the Lanczos filter is a low-pass > filter, so I guess better quality can be expected when using it. I'm trying, let's see how it goes.