ATI HD6850 & 5.1 Gaming through HDMI

I have the 6850 and You only get 2ch PCM in games.

You get multichannel bitstreaming audio in BD/DVD's over HDMI but in gaming at least I've tried L4D2, Dirt2, killing floor and only get 2ch PCM. I belive that you'll need a Dolby Digital Live with spdif or 7.1/ 5.1 analog output for that.

I have a Sapphire 6870, but I route 5.1 audio from my Audigy sound card to my home theater setup with six (greatly extended) analog audio cables. It works great.

Well When I first tested My Asus HD 6850 connected to my Yamaha Reciver via HDMI the input source reads LPCM but 2ch are activated (this is while gaming) once I pop up some movies I do get the proper dolby or DTS info....but you can alway turn the DPLIIX on your AVR to play 2ch in 5.1/7.1 It's not the best solution but it beats the 2ch only solution. I ended with a Asus xonar sound card that has Dolby Digital Live and 5.1/7.1 analog connections and use my ps3 for movies.

The 6850 should do it. The common problem I see is that the card is not configured properly.

To get multichannel PCM over HDMI with a graphics card that supports it, you usually have to set it up in Windows' sound options. It is common for the device to be known as "Speakers" in the options despite being an HDMI card.

Anyway, in the sound control panel, select the "configure" option for the relevant device and change "Stereo" to "5.1 Surround" or "7.1 Surround."

Hooked up one of my gaming pc's to my Onkyo receiver the other day and played several games. Metro 2033, COD MW2, Just Cause 2, and Mafia 2 were all coming through loud and clear in 5.1 surround, and it sounded great. Using HDMI out of my ATI 5850 to the receiver, sending both video and audio. As MSmith83 pointed out, make sure you go to the windows control panel, click on Hardware and Sound, then under the sound heading, click on "manage audio devices". A window will open up and show you your sound options. On all 3 of my PC's, the "ATI HDMI output" option shows up at the top. Click on this to make it your default audio device. But don't think you are done! Make sure you click on "configure" and then select if you have 5.1, or 7.1. Run a test tone to check all of your speakers and then you should be good. Windows will take care of the rest. All of this is assuming you have Windows 7 as I do.

After reading this and uninstalling and reinstalling the video card driver the PCM 7.1 audio is working last time I spend about an hour with every setting I could find and did not work, only 2ch PCM. Maybe a bad driver install. I was testing the sound Quality of the HD 6850 vs SPDIF and analog outputs on my Asus Xonar Xense and I have to say while is not as "rich" as my xonar it does the Job. So if your not as picky as me about audio this would work, here's what my Yamaha receiver displays in the signal info display screen using the HD 6850. EDIT: I have to say that even SPDIF "Dolby Digital Live" on the Asus Xonar Xense sounds better than the HD 6850 multich PCM

I would go with the xonar because of the build quality but the sound quality will depend on your speaker/audio setup.

Thread resurrection because this is the only thread I found relevant to my interests.

How exactly would Dolby Digital Live be better than uncompressed PCM to the receiver unless you have a receiver with a poor DAC? Doesn't DD Live compress the signal into 640kbps AC3 to transport through SPDIF? Seems like keeping it uncompressed to the receiver and letting it handle the conversion would be better?

Does DD Live flavor the sound better than the unaltered version? Also, would there be a quality difference with the DTS version, I believe its called Interactive. I think it compresses the signal down to 1.5mbps?

Creative titanium here and Windows 7 64. And rock solid so far.

Assuming proper operation on the receiver's end (i.e., correct bass management and equalization applied to all signal types), PCM output is technically better since both DD Live and DTS Interactive do compress the signal into a lossy codec. A dedicated sound card that doesn't do multichannel PCM output could flavor the sound using some ill-conceived software (like dynamic range compression) that a lot of people tend to prefer these days.

However, a game's audio assets are usually so compressed anyway that it would likely make extremely little sonic difference in actual listening. I'm not kidding when I say that I've seen numerous audio samples in many games encoded in something like ~100kbps OGG or very low bit-rate MP2 (not even MP3). This provides a little perspective into what kind of quality loss to expect with real-time lossy encoding after these samples have been decoded and mixed.

One tangible benefit that PCM output does offer over DD or DTS is discrete 7.1 surround sound with the latest games.


I don't know about the actual quality difference between the two lossy encoding solutions, but bit-rate can be misleading if one is much more efficient than the other.

My guess is the Xonar is "enhancing" the audio.

That certainly seems to be the case.

Due to extreme compression artifacts heard throughout the game, I looked at the Doom 3 audio samples yesterday out of curiosity. Music is encoded in OGG Vorbis at just above 30kbps (yes, 30). That explains why it sounds so tinny. Sound effects were given similar treatment, and it shows given that sounds tend to smear a lot in that game. The plethora of different EAX reverb effects do mask it all a bit.

One thing I've noticed is that many older games delivered a good portion of audio samples uncompressed, albeit at a mere 22kHz sampling rate.