Sound output from Optical only 2ch

Petrolhead

Petrolhead

Petrolhead

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I have a Gigabyte x99M mobo with Realtek HD on board sound.

I have just bought a AV Receiver and an optical cable.

I can get sound but it only seams to be 2 channel.

Now excuse my ignorance as this is the first time I have hooked up an AV Amp to a PC.

I have home cinema and its dead easy. The Blue connects to the amp via HDMI and bobs your uncle, Dolby Digital or True HD :)

So where am I going wrong?
 
I think so long as the source (i.e. a firm with 5.1/7.1) has Dolby Digital or DTS, it should pass through to the receiver no problem?

What audio source are you testing on by the way?
 
IIRC it will come down to using the right format - and I don't think you can do uncompressed multi channel PCM over optical? think you need to use HDMI to get that.
 
To get 5.1 over optical from DVDs you need to set both playback software and sound hardware to pass through SPDIF. That will send the pre-encoded Dolby Digital 5.1 or DTS 5.1 to the AV receiver. The encoding is required because Optical (SPDIF) is natively a 2 channel format.

For games, or other 5.1 content that isn't pre-encoded you would need to use a sound device that can encode 5.1 (either Dolby Digital Live or DTS Connect). I don't know if your motherboard is capable of this or not.
 
I can't see any mention of Dolby or DTS in the motherboard description.

That means that you can still potentially get 5.1 from DVD or Blu Ray to send via optical - because it's already encoded on the discs.

For any sound that the computer generates (e.g games) you will need either Dolby Digital Live or DTS Connect. You might be able to find a driver option for this but I don't think your EULA for the board covers it (licensing fees would be due to Dolby or DTS).

So the legit options would be:

- Use HDMI audio via your video card. HDMI supports multi-channel audio without encoding.
- Get a dedicated audio card with Dolby Digital Live or DTS Connect. This will allow audio to be encoded to 5.1 via an optical cable.
 
Glad you got it to work. There was a thread some time back that gives a link to a guide on how to get this working.

Nearly all Realtek codecs are capable of Dolby Digital Live and DTS Connect, it's just that many manufacturers disable it within the software. Probably to avoid paying licencing fees on lower end and mid range boards, and also so they can use is it as another feature to help sell their top end expensive motherboards.

HDMI is better though, as it can support uncompressed lossless audio streams without the need to encode with Dolby or DTS first.
 
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