Realtek Digital Output(Optical) can only choose 2 channels

[c👌de_g🎷]

Although my motherboard (MSI 970A-G45 (MS-7693)) can support 8 channels, both the SPDIF and Optical port settings in the Windows sound control panel can only select stereo/2 channels. My HDMI audio out from my video card allows me to configure all the way up to 7.1 surround, but that option is greyed-out for me for the Realtek options.

[img]http://i.imgur.com/sANzoNM.png[/img]

The Realtek HD Audio Manager also reflects this limitation as my only options are sound effects and doesn't provide any sort of speaker configuration.

[img]http://i.imgur.com/GMJ53cm.png[/img]

I have tried reinstalling my Realtek drivers to no avail. There are numerous threads online detailing the same issue, but none have seem to come to a definitive solution or one that doesn't require external programs to remap the sound channels.

[Silikone]

Optical only supports surround through compression, something that not all hardware can do in real-time.

[Demache]

For surround support over coax or optical, it needs to be compressed. Usually with Dolby Digital or DTS.

Onboard and cheaper soundcards won't usually support this, its more for digital stereo and surround in movies (where the surround audio is already part of the video). I've heard of software that can do it too, but that costs money because of licensing.

Best option for surround is good old fashioned analog multichannel outputs, which your onboard does support. Though the onboard in my case sounded really weak so I went with a ASUS Xonar DG which was a noticeable improvement, so be prepared for that.

[c👌de_g🎷]

It looks like the signal is already being compressed by Dolby/DTS/WMA, and although Realtek and Windows label it as 2 channels, it's actually transmitting 5.1; I have the optical running to a 7.1 receiver and in control panel sound testing, it plays through my front, centre, surround, and sub.

[b]EDIT:[/b] Never mind, it was just my receiver mixing the 2 channel signal into 5.1 automatically, it wasn't actually transmitting that way. I'm just going to buy a soundcard that supports 7.1.