@baisaz

I wonder which is worse: AHI doing the resampling or the card itself? People get around the problems on Windows by just doing the resampling in the media player itself.

It depends on the algorithm used for resampling by the card. If it just drops or repeats some samples (nearest-neighbour), AHI wins. If it uses some kind of FIR filter - AHI looses. And in fact doing resamling in the media player may be the best solution quality-wise. On MorphOS, MPlayer is able to resample on request.

I've studied the whole subject with Efika. Its AC97 codec is a minimalistic one and supports 48 kHz only. Then AHI is forced to resample 44.1 kHz streams. Distortions are easily hearable when playing sine sweep tone going up, a "mirror" tone going down appears. It is caused by well known aliasing phenomenon. When such tone is played via MPlayer forced to do resampling itself, the mirror tone is not hearable (MPlayer resampling routines keep aliasing below -60 dB level).

I will do similar experiments with SB Live in my Power Mac next week (the card is not here yet).