Prot,
The reason the emu doesn't have sound is because it used zilmar's plugin specification for windows. Thesere were seperate *.dll that people would create for GFX, SND and Input. The Author of Daedalus already had Internal GFX and Input but didn't have Sound support implemented...
He was working on adding sound and then hopefully releasing the source diffs when he completed it. So the only way you will get sound out of the emu is to code the audio section on the pc sources and then port it to the xbox again because we don't have the code that he has been using to continue the work.
Hope that helped.