HTPC – HDMI audio

HTPC audio over HDMI – why does it have to suck so much? I’ve learnt a lot about the limitations of PC-based entertainment systems in the last few weeks. And I hope to deliver a series of scathing posts that outline my failures along the way. A lot of this you can put to down to a learning experience (I’ve not built a PC for quite a few years) and my stubbornness regarding the use of Windows XP instead of Windows 7. But I’ll get to that at some stage.

On my HTPC I’m running Windows XP Pro SP3, a dual-core Intel chip, MSI mobo with onboard RealTek audio, 2GB RAM and an AMD/ATI 4350 video card with VGA, DVI and HDMI. I’m using the really quite excellent XBMC as the media player. In and of itself this is fine. I have it hooked up to a Sony STR-DG910 7.1 receiver which then passes the video on to a Sony projector.

So, the cool thing is that you can run audio through the graphics card (one cable to the receiver), if you load up the ATI HDMI audio driver. There’s a few things to note though.

If you find that you’re only getting stereo output even though you’ve adjusted the speaker settings in the XP sound control panel, chances are your receiver is passing audio through to your projector or TV. It is then telling the receiver that it can only do stereo. And so the receiver then tells your PC the same thing and it adjusts accordingly. You’ll need to dig through the receiver’s setup and stop it from passing audio on to the display device. Becuase you’re speakers are hooked up to the receiver, right?

While the nerds are happy that the graphics card outputs 7.1 LPCM I am not. When I listen to music, unless it’s been mixed for multi-channel, I want it in stereo. Same goes for OTA TV shows I’ve recorded. I don’t want everything coming out as 7.1 because it just doesn’t sound right. I could fiddle around with XBMC’s sound output and adjust it depending on what I’m listening to, but  really I want it to work it out for itself. Now, I think the one of the main reasons for this is that it’s a limitation of the card. But it seems to be also a limitation of XP as well. I’ve done some reading on multi-channel HDMI soundcards and it seems that they can all solve my problem, but not under Windows XP. Even if I go and buy PowerDVD 10 or whatever I think I’ll still have this issue. What I haven’t tried yet is using the analog outputs on my onboard soundcard to see what kind of decoding is available, although I fear it will be the same story. Any time you configure a PC with 7.1 speakers it thinks you want to use them all, all of the time.

I know, a lot of this could have been avoided by buying a copy of Windows 7 and using some of the media centre stuff built in to that. And I may still go that route. And yes I tried mythbuntu and no I don’t want to spend 3 hours getting my kernel recompiled and downloading SVN releases of code from various repositories just to get my TV tuner working. I’ll keep you posted on how things progress.

4 Comments

  1. Pingback: penguinpunk.net » Blog Archive » HTPC – HDMI audio | World of HDMI News

  2. Thanks Bren. Yes this would have all been a lot easier if I’d gone with W7. Although I have had some luck with PowerDVD10 and getting reasonable codec support and output. But it still feels kludgy …

Comments are closed.