5.1 Only producing 2.0

Astrates · 3 Dec 2011 at 18:35

I have my Blu-ray Home Cinema system attached to my P8P67 MoBo via an Optical connection. I'm also using the latest RealTek HD audio drivers but I don't get 5.1. For instance in Skyrim if someone is talking to me it'll switch between left and right for direct but even if they are behind me it comes from front speakers.

Any ideas?

Marsman · 3 Dec 2011 at 18:55

It's because the majority of PC games do not use DTS or Dolby 5.1, like DVD's and Blu-ray's do. Some games do though, I think Battlefield games do.

When watching a DVD on a PC connected to a home theatre system, the Dolby or DTS 5.1 track will be passed on by the software media player to the external home theatre system to decode. As games do not have Dolby/DTS tracks, you only get stereo.

SPDIF (optical/coaxial) was designed to be stereo. Only later did companies think of using SPDIF for 5.1 and surround sound purposes. Dolby Digital and DTS were created in order for 5.1 sound to be compressed, so that it can be sent over optical or coaxial.

So unless the sound is encoded with either Dolby or DTS, you will only get stereo.

What you need is Dolby Digital Live, or DTS Connect. Both are real time 5.1 encoders, that take any sound and encode it so it can be passed on to an external system, to be decoded.

Some motherboards come with these features, although they tend to be the higher end boards. Majority of boards do not have these features though, so a sound card is needed that can encode to Dolby or DTS 5.1 in real time.

Cheapest card that can do this, is the Xonar DS. It can only do DTS though, not Dolby. Cheapest card that can encode to Dolby, is the Xonar D1/DX. That can't do DTS, only Dolby.

Astrates · 3 Dec 2011 at 19:12

Thanks. The Xonar DX seems a good buy to get both DTS and Dolby through it for £57

Marsman · 3 Dec 2011 at 21:46

DX can only do Dolby, not DTS.

X-Fi Titanium or Xonar D2/X can do both.

You don't necessarily need both though. You're home theatre system will be able to decode both, so choose the card based on whether you prefer Dolby or DTS.

You can of course get a card which does both, if you want to. But you can only use one or other at any one time. Plus you'd be paying more for a card that can do both. Entirely up to you though.