Vista - Vista 32bit Audio - 5.1, SPDIF, Partial issue

New member here. I posted over on The Green Button, but not getting any response... looks like this forum is attended by a more responsive folk!

I am having difficulty getting Vista to play 5.1 audio - but not across the board.

Symptoms:
1. When I go into Control Panel >> Sound >> select Realtek High Def Audio device Properties and then go to the Supported Formats tab, when I click Dolby Digital and Test, I don't hear any sound
2. When I check that Dolby Digital box on the Supported Formats sound tab, and try to play DVDs or multichannel .dvr-ms files, I get no sound
3. When I uncheck the Dolby Digital box and play a DVD, I do get sound from 2 speakers
4. When I play a .mkv file with DTS I do get 5.1 sound
5. When I play a Blu-ray disc through Arcsoft TotalMedia Theatre, I have the "downmix" option selected in the software, and I do get 5.1 DTS sound

My specs:
Vista Premium 32bit
AudioMAX daughter add-on card with S/PDIF-out, capable of Dolby Digital 5.1 surround
Realtek audio drivers, the latest from the OEM website (Abit)
FFDShow installed (in theory, configured to pass through AC3 to SPDIF)
AC3Filter installed (in theory, configured to pass through AC3 to SPDIF)
HK Receiver that can process Dolby Digital and DTS, via optical spdif

Anyone have an idea of why this is happening and how I can get my DVDs and .dvr-ms surround files to play in 5.1 Dolby?

Hi Welcome to the forum

I'm not familiar with your player(s) but I have setup a number of soundcards, decoders etc to get SPDIF working correctly. The problem normally occurs because somewhere between the codec>player>soundcard something is altering the sound output.

Your ext amp will only select DTS under the following situations:

• Your DVD outputs DTS - Sorry but it wouldn't the first time and that is selected;
• Your player (WMP, PowerDVD, FFDShow) is configured to output SPDIF and with all sound enhancements turned off;
• VMC is configured to output SPDIF - only needed with certain sound cards;
• Your soundcard is configured to output SPDIF and with all sound enhancements turned off;
• Vista Playback devices (Right Click on the speaker icon in the bottom right corner of the screen) is set SPDIF Interface.

Let me know if the problem remains after you have checked these.

UKMedia

Thanks. I did a check on all five items, and all are a "yes."

I was fiddling around with this tonight... here is some additional info that should help isolate the problem:
1. When I try to play the multichannel dvr-ms file or DVD with Dolby digital 5.1 in Vista Media Center, no sound at all
2. When I try to play those same files in Windows Media Player, I get 5.1 surround!

So... with VMC being my main interface to playing these files, any ideas about how to play these files through VMC?

Okay.

Has this ever worked on this installation?

What Decoder have you got installed?

Try this link and make sure that the correct decoder is being used.

The MediaCenter Expert: Vista Media Center Decoder utility

Regards
UKMedia

Yes, I did have this working for about a year. It's been broken for a month or so. I don't remember installing any programs at time of breakage... not sure if it was a Windows Update that broke it or what.


Microsoft MPEG-1/DD Audio Decoder

I also have FFDShow and AC3 Filter installed. Both are (supposedly) configured to do SPDIF passthrough with no audio processing.

Did you run the utility?

Yes, in fact I had found that tool and had ran that utility last night. Microsoft MPEG-1/DD Audio Decoder is what was listed in the Audio drop-down.

This is strange. When you set VMC up, did you select cable input and 5.1 speakers in Media Center Set Up>Set Up Your Speakers?

Yes. To be sure, I went through the speaker setup again last night, chose Toslink Cable (S/PDIF) as the input, and selected 5.1. speaker setup. Still no sound on Dolby Digital DVDs and multichannel dvr-ms files.

As I was playing around with this last night (again), I found a confusing scenario. When I open Windows Media Player and play a multichannel dvr-ms file, I get no sound. Then I play a dvr-ms file with 2-channel sound and get 2-channel sound. Then I quickly go back and play the multichannel dvr-ms file, and I get 5.1 sound. I can't reproduce this within VMC.

So still no 5.1 within Vista Media Center. Wow is this frustrating.

I have had problems in the past with a new sound card driver, which may have been installed by Windows Update. Have you tried rolling back the sound card driver?

UKMedia