HTPC sound problems

[Mal]

Hi All,

Back again with another question.....

I have fitted a NEC 1300 A DVD RW into my Shuttle HTPC set up.

What I wanted to do was be able to play DVDs on it and through the Optical out at the back, pump sound into my AV receiver. Unfortunately it's not being interpreted by the AV receiver properly. Instead of 5.1 surround sound it is only coming theough the front centre, left and right...nothing through the rear speakers nor the SubWoofer.

Have I missed a setting or is this a hardware issue or just not possible to get dts/Digital Cinema sound from a Shuttle to the AV Receiver.

If you can advise I would be most grateful
Mal

[shifty.ricky]

Have you told the sound card to use 5.1 speakers.

It seems like the AV center is using stereo and the centre is a mix of both.

[Sama98b]

As far as I know the onboard sound chip has only two chanel digital/optical "s/pdif" out.
Analog it can do 5.1. You have to use the old cables.

[Big Adam]

The output through the optical output on the Shuttle should be 'raw' data from the source so long as you have selected 'enable spdif' somewhere in your audio settings.

Are you playing DVDs or CDs through the DVD player to test it? A CD will of course only produce stereo signal which your receiver will reproduce as a left-centre-right sound unless you select a surround mode such as 'Dolby Pro-Logic II' to force it to process the sound into a 5.1 signal.

If you are testing using DVDs, ensure that within the DVD's languages menu, you have selected a multi-channel audio track (DTS, 5.1 etc etc). I haven't checked but if Sama98b is correct, then you want to select a stereo output and let the receiver do the work as with the CD advice above. Disappointing if this is the case. You'll have to upgrade the sound card to one with full multi-channel support.

Sorry if the above advice sounds basic, just trying to cover the obvious before looking deeper. What receiver do you have?

Big A

[shifty.ricky]

Also check the DVD software. Sometimes it downmixes it to 2 channels.

[Mal]

Originally posted by Big Adam
The output through the optical output on the Shuttle should be 'raw' data from the source so long as you have selected 'enable spdif' somewhere in your audio settings.

Are you playing DVDs or CDs through the DVD player to test it? A CD will of course only produce stereo signal which your receiver will reproduce as a left-centre-right sound unless you select a surround mode such as 'Dolby Pro-Logic II' to force it to process the sound into a 5.1 signal.

If you are testing using DVDs, ensure that within the DVD's languages menu, you have selected a multi-channel audio track (DTS, 5.1 etc etc). I haven't checked but if Sama98b is correct, then you want to select a stereo output and let the receiver do the work as with the CD advice above. Disappointing if this is the case. You'll have to upgrade the sound card to one with full multi-channel support.

Sorry if the above advice sounds basic, just trying to cover the obvious before looking deeper. What receiver do you have?

Big A

Thanks Big A....you cannot upset me by assuming ignorance ..... I am not overly knowledgable in all of this so starting from 1st principles is good ;)

The AV Receiver is a Sony STR-DB1080.

I am testing with a DVD which when I play through my Sony DVD player lights up the Blue Multi Channel input light (if you are familiar with the AV Receiver) and sounds wonderful.

When I play it through HTPC the Blue light does not come on and the sound is very flat....only the Front Left Front Roight and Front Centre speaker are producing sound. Even if I fiddle to force Surround Sound it sounds poor.

I changed the setting on the DVD player (Showshifter) to play DTS and got no sound at all.

I have enabled 5.1 *everywhere* I can find it. I have not found anywhere to "Enable S/PDIF" so I am wondering if that might be the key.....do you know where/how to enable that?

Thanks for your help
Mal

[Cable Monkey]

Showshifter uses the software player already installed for its codecs does it not? From memory I think you need to launch that (PowerDVD or WinDVD) first, then go into tools, Audio and tell it to use SPDIF. It sounds like you have a downmix of the DD soundtrack output as PCM and DTS does not downmix, hence the silence.

[shifty.ricky]

Get a copy of Power DVD.

I know for a fact that has an "Enable SPDIF". I have to enable SPDIF for my audigy to decode the 5.1 signal. Otherwise it doesnt work.

Try it then. I am sure that its the software.

[Mal]

Originally posted by Sama98b
As far as I know the onboard sound chip has only two chanel digital/optical "s/pdif" out.
Analog it can do 5.1. You have to use the old cables.

Hi Sama

I have been following the advice from the board and have tried just about every possible permutation of DVD player and setting. I can only get stereo out of the optical. DTS is silent. :(

When you say I have to use the old cables....what does that mean? Is there a single cable I can connect from the PC to the receiver which will enable me to pass a DTS 5.1 "signal" to the receiver? Can you tell me what that cable is called?

Many Thanks
Mal

[Mal]

Success.....I am a happy bunny!!! :)

What I had missed was that the audio chip on the shuttle is "getting in the way".

By bypassing it in Device Mangler the raw stream that was referenced earlier in this thread does indeed get passed to the AV receiver and I am now able to enjoy lovely DTS sound through the SPDIF via an optical cable into the AV receiver.....

thanks for your help/inspiration, guys.....
Mal

[Big Adam]

All's well that ends well.
'Sounds' like a sweet setup.
Big A