Radeon HD 4550 HDMI audio getting rear channels only

[Martoon]

NOTE: Please disregard this first post, and go directly to this post. Since trying some more things, I've discovered that the problem is related to playing DVDs, and not to the HD 4550 HDMI audio.

I have an HD 4550, and I'd like to use its HDMI audio. With the card and driver installed, the only audio device that shows up for it in the Windows XP sound hardware is called "ATI HD audio rear output". If I select and use this sound device, I get sound, but in movies with surround sound I only get the rear channels (it's just a two-speaker TV and stereo, and the two speakers are getting the rear channels).

If I use the onboard audio from the motherboard (instead of the videocard's HDMI audio), I get the proper stereo channels. But I'd like to use the HDMI audio.

Anyone else have any experience with this? Does the HD 4550's HDMI audio only put out the rear channels? That seems a little odd to me. But even docs on ATI's site tell you to select "ATI HD audio rear output" to use HDMI audio from the video card.

[Fuzzy]

the 'ATI HD Audio Rear Output' refers to the jacks location on the PC, not the channels it is supposed to represent. Also, you have to realize the limitations of using HDMI Audio to your television directly. You will have to make sure the speaker setup is set to Stereo Speakers, and that you make sure it's not trying to output Dolby Digital, or DTS, or anything but Stereo PCM (as that's all your set is going to accept).

[SWKerr]

You should have an option for ATI HDMI Output (ATI High Definition Audio Device) I usually have this set as the default audio device but you can select it in Sage as well.

Go to the ATI site and download the latest drivers for that card.

[Martoon]

Originally Posted by Fuzzy

the 'ATI HD Audio Rear Output' refers to the jacks location on the PC, not the channels it is supposed to represent.

That was my interpretation, but after I was clearly only getting the back audio channels when playing a DVD, I was starting to wonder. Good to have confirmation that the name has nothing to do with stereo channels.

Also, you have to realize the limitations of using HDMI Audio to your television directly. You will have to make sure the speaker setup is set to Stereo Speakers, and that you make sure it's not trying to output Dolby Digital, or DTS, or anything but Stereo PCM (as that's all your set is going to accept).

Where do I set that? Under Control Panel > Sounds and Audio Devices > Audio tab > Sound Playback Default Device (where I have 'ATI HD Audio Rear Output' selected), I click the Advanced button, and there's a Speakers tab. I have it set to Desktop Stereo Speakers right now. I've poked around in all the audio settings, and haven't found anything referring to Dolby Digital, Stereo PCM, etc.

I have an HDMI cable going from the video card to the HDMI port on the back of the TV. The TV is an LG 42PC3D, with these connection plugs. I have an RCA cable from the AV OUT to my stereo's input (and I know the problem isn't there, since I get the same audio issues if I turn on the TV's internal speakers and listen through that).

In the audio menu options on the TV, there's a Front Surround setting, where the options are Off, 3D EchoSound System, or SRS TruSurround XT. I have it set to Off (and I've tried the other two).

The audio tracks available on the DVD are English AC3 5.1, English AC3 w/Commentary 1, and English AC3 w/Commentary 2. I have the first selected.

Originally Posted by SWKerr

You should have an option for ATI HDMI Output (ATI High Definition Audio Device) I usually have this set as the default audio device but you can select it in Sage as well.

Go to the ATI site and download the latest drivers for that card.

This is a new HTPC build, where I've just installed XP and all new drivers (including the latest drivers for this card from ATI's site). I installed the HDMI audio driver again last night, to be sure. The only audio devices I have to select in Windows are 'ATI HD Audio Rear Output' and 'IDT Audio1' (the motherboard integrated audio). The audio renderer in SageTV is set to Default, so it's using this.

Again, if I set the default audio device in Windows to 'IDT Audio1', then play the DVD with headphones plugged into the motherboard's audio jack, it's fine. But I'd really like to get the HDMI audio working correctly.

Any other suggestions?

[SWKerr]

What Motherboard are you using?

Pick the custom install with the ATI package and make sure there is a HDMI Audio Driver option that is selected. Also: Review the log when it is done to make sure there were no errors.

[Martoon]

Originally Posted by SWKerr

What Motherboard are you using?

NFORCE NM-A

Pick the custom install with the ATI package and make sure there is a HDMI Audio Driver option that is selected. Also: Review the log when it is done to make sure there were no errors.

It's separate drivers for the video and the HDMI audio (here). There is no HDMI Audio Driver option in the video driver custom install. I've installed both drivers, and it didn't explicitly report any errors (I don't know where it puts the log). I am getting audio through HDMI; it's just that it's only the back surround channels. And 'ATI HD audio rear output' is the correct device to select. I've found some documentation from ATI on how to use HDMI audio in XP and Vista, and that's the device name they refer to.

[Martoon]

Okay, major realization here. I had thought that DVDs sounded fine through the motherboard's integrated audio, based on having plugged headphones into that jack and trying one DVD. I was just trying that again, and realized it was just because I had the volume up louder, and could hear voices a little better. I was now trying it some more, and can hear that the motherboard audio is doing the same thing as the HDMI audio. I'm getting rear channels, and no front. Actors in front of the camera are very muffled and faint, while actors and sounds from behind and the sides are much louder and clearer. Recorded TV all sounds good. It's just most DVDs.

So it seems the problem is with DVDs, no matter which audio device they're played through. It happens if I play the movie directly from the DVD, or if I rip the VIDEO_TS files to my hard drive and play from there. It also doesn't matter if I play the DVD through Windows Media Player, or through SageTV. But the same DVD sounds fine on my desktop PC.

So what is it about playing DVDs on my HTPC machine that makes this happen?

[SWKerr]

The Win7 and Vista drivers include the HDMI driver with the main install. I have not used XP in awhile but the description sounds off from what I remember.

Read this. Your problem sounds similar. Look a Clift's post\solution.

http://forums.sagetv.com/forums/show...&highlight=ac3

[Martoon]

Originally Posted by SWKerr

Read this. Your problem sounds similar. Look a Clift's post\solution.

http://forums.sagetv.com/forums/show...&highlight=ac3

That was it! Changed the AC3Filter properties, and it's all good now. Thanks!