PC Sound SPDIF and Home Theatre amp

Silmaril

I have my pc hooked into my home theatre setup, and everything is wonderful except for the sound. I have a coaxial digital cable connecting the SPDIF from my sound card into the digital input in my amp. I get sound fine, but only in stereo.

Now, my understanding is that unless the source sound is encoded in 5.1 all I will get is stereo, as the signal won't be converted on the fly over the digital channel. If I play a DVD encoded in DTS, then I'll get the full 5.1, but anything else will just use the front left and right channels.

I've heard that there are sound cards that will convert the sound to 5.1 and send it down the SPDIF channel, so can anyone point me in the directions of cards that can do this?

Ta.

Nakatomi2010

Operating system? codec pack? I ran into a similar problem on my vist 32-bit using the vista codec packs... Lemme ask ya this... When playing a regular DVD does IT play 5.1?

bombardier

I'm pretty sure this is the only card that does what you want at this point in time: Razer Barracuda AC-1

MrOletta

I had this problem as well, and this is my solution:

My receiver has RCA jacks in the back under DVD for Surround, Center, Front (2 RCA jacks per). I bought 3x RCA -> 3.5 mm and connected them via those.

On my PC sound manager, I was able to set up everything properly to get 5.1 this method. I do, however, still have a SPDIF running and I switch to that channel if running anything that is encoded in 5.1.

Perhaps that's a little confusing, so here are some pics!

My receiver:


The RCA -> 3.5mm jacks (3 of these cables)


I connected each cable to the L/R of each DVD channel and connected those to my PC soundcard. When I want to watch something not encoded in 5.1 I simply hit the 'DVD' selection on the receiver.

Nakatomi2010

I just re read the original thread...


I think your issue is the same as mine... Let's say you're using the Vista Codec pack...

Click on Start>Programs>VistaCodecs>32-bit tools>Audio Decoder Configuration

Under the Codecs section you'll see a column for Decoders change the ones you want to S/PDIF.... This is what I had to do... Took me weeks to figure it out, but now all of my DVD backups give true 5.1 audio now... I'm connected to my receiver using Toslink

vonPoonBurGer

I've heard that there are sound cards that will convert the sound to 5.1 and send it down the SPDIF channel

Have you tried selecting Dolby ProLogic II decoding on your amp? That can also take a basic stereo signal and distribute it amongst your speakers. That's why most amps have a "straight stereo" mode, so audiophiles can bypass all DSP when playing a 2-channel recording (e.g. most CDs). I'd imagine your amp would do as well as a sound card in terms of upconverting from stereo to 5.1, and cost you nothing extra to boot. The only downside I can see is that you might have to manually switch between Dolby PLII and Dolby Digital depending on whether your computer is putting out a true surround signal, or just basic stereo.

Weretaco

These guys also make cards that will do real time 5.1

http://www.auzentech.com/site/products/feature.php

What you need is something that does dolby digital live. It's a decent solution, but I tend to keep my audio stereo for quality reasons and just pass through the 5.1 from pre-encoded stuff.

Nakatomi2010

For the record I had a similar isssue to him and I used a BlueGears X-Mystique sound card... I had to fix my issue by doing what I explain above...

bombardier

Weretaco wrote: »

These guys also make cards that will do real time 5.1

http://www.auzentech.com/site/products/feature.php

What you need is something that does dolby digital live. It's a decent solution, but I tend to keep my audio stereo for quality reasons and just pass through the 5.1 from pre-encoded stuff.

Ok this is the one I was thinking of initially. I knew it started with an A.

Silmaril

bombardier wrote: »

Weretaco wrote: »

These guys also make cards that will do real time 5.1

http://www.auzentech.com/site/products/feature.php

What you need is something that does dolby digital live. It's a decent solution, but I tend to keep my audio stereo for quality reasons and just pass through the 5.1 from pre-encoded stuff.

Ok this is the one I was thinking of initially. I knew it started with an A.

Yeah this is the sort of thing I was looking for. I know the quality isn't going to be as good, as the card has to encode everything on the fly, But I'd rather sacrifice a bit of quality and have 5.1



A card with Dolby Digital Live is what my googling came up with too. Thanks for your help guys.

Krikee

Your receiver (assuming it's a receiver/amp combo) doesn't support Dolby Pro Logic, does it? That would be the first thing I try.

Silmaril

My amp does DTS and pro logic.


For anyone else interested, this is what I've turned up. Unless your soundcard does Dolby Digital Live you will not get surround through the SPDIF/optical output unless the original source is already encoded in Dolby Digital 5.1 ie a DVD. The dolby digital is passed through the SPDIF in its raw state, and the amp then decodes it. Any other signal is sent as Stereo, as the SPDIF inputs were never designed to cope with an analogue 5.1 signal. All that gets sent down is the front left and right channels.


With a Dolby Digital Live card, the signal is encoded into 5.1 Digital in the hardware before being passed through the SPDIF before being decoded by the amp.

Weretaco

One thing to note. Those of you who have older nforce2 based motherboards have this feature for free with Nvidias soundstorm audio.

Too bad they stopped putting it on boards and haven't made a standalone card yet.