Don't think a lot of people still use the old Aureal sound cards, but unfortunately I am... hope Nathan sees this anyway. :s
This applies to WinXP, using the crappy the WDM driver. The problem is with sounds clipping and not playing above 16 channels. The problem arises because the driver reports (in the log file) that there are 96 (!!!) sound channels (buffers) available, where in reality it seems to be only 16.
When you set sound buffers to use hardware for Directsound and Directsound 3D, and greater than 16 channels, the sound problem occurs. Using the "auto" setting doesn't help either... I think it tries hardware buffers first, then falls back to software ones, but since the driver reports that there lots of hardware buffers left, it never happens.
After pissing around with the options, the best workaround is to set Directsound 3D to use hardware and Directsound to software. The reason to do it this way is that you lose the phase shift/doppler effects if Directsound 3D is done in software (at least I think). Set Directsound 3D to 16 channels, and total sound channels to 64.
While it's only 16 channels of full 3D, the extra stereo channels adds immensely to the ruchness of the sound, especially in big battles. So far I've seen and heard the game use up to 62 channels... oh man, nirdvana indeed! ;)
The fix would be a proper WDM driver (yeah, right), or an option (probably in gameprefs.ini) to override the number of hardware buffers, so we can use "auto" sound buffers properly (Nathan?). But the workaround is probably okay I guess.
Cheers :D
If the drivers report inaccurate settings, nothing bz2 could do about that. Just do not set it higher then 16 in that case.