10 years behind

[blasted]

Im a bit new the computer audio arena and as such have a very basic level question for all you tech heads, if you would be kind enough to help out.

I have recently built a home cinema set up, 5.1 b&w (.1 still to be added) i have the onkyo 605 amp and connected to that is my dvd, projector and cd player.

Now i have some films on my computer (264), some have either dts sound, my computer is connected from the motherboard sound output (3.5mm jack) this splits into red and white coax, which is plugged into the game input on my amp. Which only outputs in stereo.

So if i want to get the dts sound i need a sound card that has a spdif output? would that just send a stream to the amp so the amp can do its jiggery pokery? would this also work for my counter strike, which is only stero at present?

secondly if i got a decent sound card xonar or something would i still use the optical to play music through my amp?

[Gixxerblade]

SPDIF will send the Dolby Digital or DTS bitstream to your amp for it to decode it. If you want to use a Xonar you can buy software like PDVD, TotalMediaTheatre or a plug in for Nero showtime which will enable you to decode hd audio on blu-ray such as TrueHD and pass it through the analog outputs like you are doing with stereo at the moment - obviously you will need a couple of extra cables.
The Xonar will also have SPDIF out so you can send the DTS as a bitstream for your amp to decode if you like, you could try both and see what you prefer.
The difference between the two methods is in the bit rate. DTS on blu-ray is 1.5mbps and on standard defintion dvds it is usually 754.2kbps, on blu-ray it is lossless but compressed and called DTS Master Audio and has a much higher bit rate. The analog method also enables you to send PCM. You cannot send lossless compressed or lossless PCM via SPDIF except in stereo -which is what I do for music, so obviously it can't be used for 5.1 or 7.1 bitstreams from the hd soundtracks. It can be used for the 1.5 and 754.2 soundtracks though. Sorry if I'm confusing you but it isn't easy to understand or explain I find.
I have read comments where people say they prefer the analog hd soundtracks but I've also seen comments that DTS at 1.5mbps is identical to the hd version using hdmi from a standalone blu-ray player i.e. everything was the same, same connection method, same amp and same speakers and just the soundtracks were being tested. When you get more in to it have a play and see what you think - only your opinion counts at the end of the day.
Music is the same either get the card to digital to analog convert it and send it out through analog or use spdif via optical or coaxial and let your amp decode it.
I use SPDIF via coaxial from my Asus P5b motherboard and Vista in to a Lexicon processor and use Logic7 Film for watching films with DD or DTS soundtracks and for music I use the same connection with files on the PC stored as wav (PCM). My processor does all the decoding and I use WMP11.
There are different ways of doing things and different operating systems to contend with and different software applications for music and films, it can seem confusing but all the information you need is on this site.
Hope that helps - but it probably doesn't

[blasted]

Thanks for that

I get the gist, at least i think i do, which probably means i dont.

I can out put the data as a bitstream and let the amp decode it via the optical spdif output on the card at 1.5mbps should i go the xonar route.

*newsflash*, i just looked on the back of my computer and there is a spdif in/out (should have thought of that before) i have dug out the manuals and shall have a read before i post again even more confused than ever.

[Gixxerblade]

Your Onkyo manual should have some information about the different connection types. I wouldn't be too bothered about bit rates at this stage just hook up your spdif with a cable to your Onkyo and see if you like the sound you are getting with Dolby Digital or DTS or music and games, then do a bit more research and see where you want to go from there.
The Xonar is a good card from what I can tell but I've never used one.

[Erazerhead]

For just passing the dts or dolby signal via SPDIF Xonar is an overkill.

Any sound card with SPDIF will let you send dts or dolby signal from the movie to the receiver.

Make sure it has Vista support if you use Vista, some sound cards do not.

Also see if you have SDDIF optical input or only SPDIF coaxial.

Google e.g.: these card:
X-Fi Xtreme Audio PCI Express (optical), Chaintech AV 710 PCI (coax) , M-Audio Revolution 5.1 (coax)
X-Fi Xtreme Music PCI (coax)

[lilohtpc]

Originally Posted by Erazerhead

For just passing the dts or dolby signal via SPDIF Xonar is an overkill.

Any sound card with SPDIF will let you send dts or dolby signal from the movie to the receiver.

Make sure it has Vista support if you use Vista, some sound cards do not.

Also see if you have SDDIF optical input or only SPDIF coaxial.

Google e.g.: these card:
X-Fi Xtreme Audio PCI Express (optical), Chaintech AV 710 PCI (coax) , M-Audio Revolution 5.1 (coax)
X-Fi Xtreme Music PCI (coax)

Well... Xonar also have Dolby Digital Live, it provides something other generic MB SPDIF couldn't at all.
With DDL on Xonar, it can encode 5.1 gaming audio into Dolby Digital signal in real time, and send to your AVR to do the decoding. That's how I use my hometheater and my projector to play Quake War....^^

[Matt_C]

I have a cheap (£7) old Yamaha PCI soundcard that has analogue and a single optical output - I have no problem outputting DD/DTS 5.1/6.1, aswell as Pro Logic and plain ol stereo via the optical.

All I had to do was install the CCCP codec pack, and now WMP (11), Media Player Classic and Zoomplayer all output the multichannel DD/DTS to my amp no problem.

I'm on XP, but I should think that it would work on Vista using your onboard SPDIF connection......

[blasted]

Here is where i have made it to.

I have the computer now connected by spdif to my amp. It plays stereo fine, but if i use vlc player and set the sound to spdif passthrough, it stutters and judders. I dont have a sound card, im just using the spdif of the back of the computer. Its a dfi lan party.

Any ideas?

[dogbert]

vlc still has the passthrough bug - use something else.

both the xonar and the x-fi are overkill - they are only needed when you play games with your htpc - your onboard spdif port is up to the job, and if it doesn't work, a 15€ cmedia based card will do just fine.

[blasted]

Thanks everyone.

I have just tried media player classic and it workks fine, the little DTS light pops up when i play a film.

Im not going to bother with a sound card, instead Im going to throw my pennies at a sub to round the sound off.

[Matt_C]

I have had problems with VLC and multichannel passthrough - only on multichannel DD and DTS I would get microsecond sound dropouts. Media Player Classic has worked fine, as has Zoomplayer and WMP. Have you tried WMP to see if that passes through the bitstream? I personally don't use WMP for video playback as the controls etc are better from ZP and MPC, but I found it interesting to see that it allowed passthrough of multichannel audio after I installed the CCCP codec pack, which it didn't do before......