I can't do the work for you.
googling acer 8930g linux driver gets me this page:
http://www.linlap.com/wiki/acer+aspire+8930g
Looks like this person had some trouble with sound, but might've gotten it to partially work.
Other than updating alsa to a beta when you can, I recommend trying this link, but be aware that the first time usually ends badly when trying to fix something. At least in my experience. Good luck.