I have a bluetooth headset that I use for most of my gaming. However, when I try to use it with Starcraft 2, the audio is played in low-quality mode, the mode used for phone calls, instead of the high quality mode that it should be using. Sound in this mode is mono, despite having set the sound settings to stereo. There's also a lot of static, and it just plain sounds unplayably awful. It applies to all sounds Starcraft 2 plays - background music, unit voices, button clicks, etc. While Starcraft 2 is open, the poor quality also extends to non-Starcraft 2 sounds, such as music being played with Winamp, MSN sound effects, etc.
Here are some examples http://blog.advids.co/20-animated-explainer-videos-that-are-awesome/