I am having a bit of trouble getting my soundcard to play in 5.1. Trying to use the onboard realtek and when doing windows tests or using Media Center it plays back in 5.1 but can't seem to get it to do so in games where I just end up with stereo playback. I am connected with optical output, I do have an add in Asus DX but am trying to drop it due to all the slots 680 SLI takes up. anyone come across this audio issue before, Any ideas?
Your Realtek Soundcard won't output 5.1 over optical. Its limited to 2.0/2.1. For 5.1 over optical you'll need a sound card that outputs and transcodes Dolby Digital Live - the DX you have does. If you don't want to use the DX, your only option for 5.1 is analogue.
What Parge said ^. My other half has an onboard Realtek codec which supports Dolby Digital Live and the DTS equivalent (the name escapes me) and that was playing games over the weekend in 5.1 over optical without any problems. Check you have the latest Realtek drivers. If your codec supports DDL then it'll be made clear in the Realtek control panel thing.
