I have heard that certain sound blaster cards do not support the modification of channel pitch in real time. Does anybody know if there are any compatability issues with changing the pan of a playing sound or if there are any other general sound issues with common cards?

I'm not sure, but perhaps you should be working with an API like DirectSound or OpenAL. They handle compatibility issues for you.

Oh, and I also know that DirectX tries to emulate some features in software if they're not supported in hardware (perhaps frequency or volume?)

If your not looking to write your own, from-scratch sound routines, I would second Ted's suggestion.

Your may be aware of them, but I would recommend working with a sound library like FMod (www.fmod.org) or BASS (www.un4seen.com), as they will save you a lot of hassles and headaches.

FMod does all/most of it's processing/mixing of sounds using its own optimized software routines, and avoids the hardware save for playing the sounds. It runs on many OS's and consoles.

BASS is a higher level wrapper over DirectSound, and thus works only with Windows.

They are both free for non-commercial stuff, but requier a license for commercial use.

HTH,
David

Oops! I should have mentioned, I use Blitz3D, which uses FMod for all of its sound. I am kind of interested in things to avoid in hardware, rather than software compatability, because as far as I can tell FMod seems to be very compatible. I have recently heard that altering the pitch of a sound in real time isn't supported by many cards, which was kind of disappointing because I use it quite a bit in my game. But if FMod does it in software...?