I had what I believe to be the same issue also with the sound. I would be streaming music from the metro Xbox music app and go to the desktop, that’s when the audio from that app would get quieter like background music and no volume setting was changed.
My mainboard is an Asus P6X58-E WS which has a Realtek ALC889. I noticed this issue sometime after I installed the drivers for them. Windows 8 doesn’t seem to power down the computer anymore and puts it into what I believe is an S5 sleep state. I think this was a sound driver save state issue of some kind with the fast startup feature in Windows 8. Anyways I believe I remedied the issue by actually shutting down the computer.
Pick your solution:
- Hold shift when clicking reset to get the recovery option and choose “Turn off my computer”.
- Hold shift when clicking shutdown to skip fast startup.
- Disable “Turn on fast startup” under power options and “Define power buttons…” (This might be good if the issue keeps reoccurring)
- Use the regular shutdown and unplug or hit the power switch on your power supply.
Options 1, 2 confirms an actual shutdown on my computer. I have a sidewinder x6 keyboard and when I do the regular shutdown and press a key the red LED lights blink, which is kind of cool.
After my computer did a cold boot I didn’t have any more sound issues, at least not yet. If this doesn’t work, oh well it’s new and hopefully something gets fixed. I also claim to not know much, if anything about computers. I don’t believe all mainboards support S5 so that could explain why other people aren’t getting the same issue.