Thanks, that works nicely. But I am still having problems with the speaker assignments not working - or only working randomly. I init BASS with the BASS_DEVICE_SPEAKERS flag, then create the streams:
chan1 := BASS_StreamCreate(44100, BASS_SPEAKER_FRONT, @StreamProc, 1);
chan2 := BASS_StreamCreate(44100, BASS_SPEAKER_REAR, @StreamProc, 2);
It occasionally does work as it should, but most of the time it plays the first stream on both front and rear outputs, and the second stream is only barely audible on the right channel of the rear output. I think you or someone suggested that my soundcard (SB Live) is broken, but the audio test in Creative's mixer works just fine. I do have the number of speakers set to 4.
Anyway, if nobody else is having this kind of problem, and you're certain it's not a bug in BASS, I'll gladly buy a new sound card. Just wanted to make sure. I know you're probably quite busy and I apologize for bugging you if it indeed is a fault in my hardware.