EPThttp://us.battle.net/d3/en/forum/topic/5235397929
Many people, including myself are experiencing problems with the in-game, and cinematic sound and voices. I'm speaking to customer support about this currently, and hopefully they can provide an official solution soon. However, I'd like to provide an option to those who are looking for a temporary solution to these issues. I've tried 2 fixes, and both have worked, to different degrees of success.
I'm having the following problems:
Front/main audio is silent, or very low
No/very few/low voices during cinematic's
Sound is positional, otherwise low
I suggest if you have ANY sound issues with Diablo 3, to try both these settings changes, they are safe and can be undone.
To troubleshoot:
Do option #1, play D3; check if audio is fixed. If fixed, ur good to go.
If #1 does not work:
revert option 1 changes, Do #2, If doesn't work/you don't like, revert all changes.
The Fixes:
Option 1
1) Start - Settings - Control Panel - Sound and Audio -> Audio -> Sound Playback -> Advanced -> Speaker Setup
First, change your speaker configuration. I'm running a 5.1 speaker setup for instance, and had to set mine to Desktop Stereo (2 speakers)
Not everyone's OS will be the same, so find your respective Speaker options, and change them to 2.0/2 Speakers/Desktop Stereo. You can try other choices, but mine worked with Desktop Stereo. This solution didn't give me any problems, Front/main channel works fine, cinematics and voices are always the same volume, etc.
Option 2
2) Start - Run - type "Dxdiag" hit enter - go to Sound tab -> Disable sound acceleration
This is the second fix, for me, it fixed everything except the D3 audio was delayed by like .5s-1s, so keep that in mind. On the Sound tab, change your Sound acceleration to "No Acceleration". You can also try changing it to "Standard" or "Basic" acceleration and see if it fixes it.
I hope this helps those of you who might be having the same issues as me, or other sound problems I haven't mentioned.
If this worked for you, reply and let me know which fix worked for you, and which audio problems you were having.
