Hello. I just wanted to post a solution to a little problem that I found with Blender and the BGE's audio playback.
You see, while using the Blender Game Engine, I happened on a problem. The problem was that I could hear stuttering in the audio playback. This was not Blender or the BGE's fault, as this also happened on other programs, like Panda3D, but not on others, like Windows Media Player. I believe it is because of the software library used to play the sound, OpenAL. Other users of Blender have experienced this problem, as well.
Anyway, I found out that the crackling was caused by the port that I used to push the audio out from the computer. Plugging the cable into a second port on my external sound device solved the problem entirely. :) Note that the audio also returned to normal if I used my computer's built-in sound card.
So, if you find that you're having problems with Blender or other audio crackling, try switching around ports, cables, or sound card settings.