Hey, everybody. I apologize in advance if this question belongs in a different category, but it seemed the most appropriate since I am using the HDMI output on my motherboard.
I recently built a sub-$300 (after rebates) HTPC for my living room, and everything is running very smoothly with the exception of the audio only outputting in 2-channels to my speakers when I should be getting at least 5.1 surround. My setup is entirely HDMI (Motherboard HDMI out --> TV HDMI in --> TV HDMI out --> Digital Receiver HDMI in). This is the exact setup I have for my PS3, and it outputs the audio correctly.
I have tried the most recent Realtek (2.70) and AMD/ATI HD Audio drivers both separately and together, and no combination works. They only provide the stereo option. (And yes, the source audio for the files I have tried is in 5.1).
Is there a motherboard BIOS setting or possibly an APU setting I am completely overlooking? It "feels" like Windows is encoding the audio files to 2-channel before sending them out to the receiver for whatever reason.
I'm about at my wits end, so thanks in advance for any help you all can provide!
Did you ever figure this out? I'm having the same problem with an MSi 880GM-E41 motherboard. Here's the weird part. When I try over SPDIF, I still can't get a 5.1 signal, but when I go into the playback device properties and, under the Supported Formats tab, use the built-in Windows test for DTS and Dolby Digital, I get sound from each speaker so the connection is obviously capable of sending the proper signal, but Windows won't let me set the speaker configuration for SPDIF and won't give me any option but "Stereo" in the HDMI speaker configuration. If I had hair, I'd be pulling it out.
For whatever reason I only got 5.1 audio when I switched the order of my HDMI connections. The HTPC for whatever reason only wanted to go directly to the receiver first and then to the TV rather than my preferred TV first then to the receiver (as it my setup with my PS3... I honestly don't get it).
So I basically decided I could tolerate "only" 1080i as long as I am getting my 5.1 audio and opted for that connection route. It's a few extra button-presses on the remotes, but it's been working great for me otherwise.
That's precisely why I didn't connect to the tv and then use passthrough to the receiver. I'm connected directly to the receiver. What's more, I disabled the audio passthrough to the tv to be absolutely sure Windows didn't see the receiver as a 2-ch playback device because of the tv at the end of the chain. On my signature rig, Windows showed the hdmi connection as "SONY TV" when connected to the receiver, but didn't deny me 5.1. I feel like this has to be a problem with Realtek because the ASUS SupremeFX through the EVGA 670 FTW+ works just fine.
Does your receiver limit you to 1080i in that connection order?