Pc to Home Cinema TOSLINK Optical

[DTCJimmy]

I just wanted to know if I get a Optical Cable is that the only cable I need to plug in to the dvd player from my PC to get all speakers working?

 

[McHenryB]

Yes, assuming that both have optical sockets.

 

[gopher1369]

Are you sure the DVD player has an optical input? Normally the optical is an output, not an input.

Also you'll only get stereo sound, optical cables are only designed to carry stereo. If you want to output 5.1 over an optical cable you'll need a sound card that supports Dolby Digital Live: http://www.dolby.com/us/en/technologies/dolby-digital-live.html

 

[hang-the-9]

Are you sure the DVD player has an optical input? Normally the optical is an output, not an input.

Also you'll only get stereo sound, optical cables are only designed to carry stereo. If you want to output 5.1 over an optical cable you'll need a sound card that supports Dolby Digital Live: http://www.dolby.com/us/en/technologies/dolby-digital-live.html

SPDIF can be used for surround 5.1 and 7.1 but it's compressed and the reciever you are using will need to support Dolby Digital or DTS. There may be some cheaper sound cards that don't work with surround out of SPDIF an you will need the other end to be able to have certain options as well, but many sound cards and recievers cando that.

I'm assuming this "DVD Player" you are talking about is one of those all in one home theater systems with amp/speakers/dvd in one unit.

 

[gopher1369]

SPDIF can be used for surround 5.1 and 7.1... There may be some cheaper sound cards that don't work with surround out of SPDIF an you will need the other end to be able to have certain options as well, but many sound cards and recievers cando that.

This isn't true, no onboard sound cards support this (that I'm aware of), No cheap external sound cards will support this either Unless the poster has something like an Asus Xonar or Creative Soundblaster card that specifically support Dolby Digital Live, he's only going to get stereo.

 

[hang-the-9]

SPDIF can be used for surround 5.1 and 7.1... There may be some cheaper sound cards that don't work with surround out of SPDIF an you will need the other end to be able to have certain options as well, but many sound cards and recievers cando that.

This isn't true, no onboard sound cards support this (that I'm aware of), No cheap external sound cards will support this either Unless the poster has something like an Asus Xonar or Creative Soundblaster card that specifically support Dolby Digital Live, he's only going to get stereo.

This is mostly true for games only, I don't know all the onboard audio brands they would have to check the exact specs on their system, even if the card's can't send 5.1 info from games, DVDs would have the surround sound info sent though cards that can't hande surround sound from games. So for games, yes you need to have an external sound card, in most cases unless you get a high end motherboard. For movies, you may still need an external sound card to send surround sound info to a reciever though optical, but it's a lot more chance that you won't need it for that from a DVD disk at least. Converted movies would likely need an add-on card like games.

What the issue with the original replay was that "optical cables are only designed to carry stereo", optical can do surround sound, just not in all situations. Maybe a "in many cases with onboard audio cards." at the end of that and it's all good

 

[hwc1954]

I use an optical TOSLINK output for all sound from computer. The digital signal from the source is the digital signal. If the the source is encoded with Dolby Digital 5.1 or 7.1, that signal will be available for decoding by the home theater receiver (if so equipped). The choice of stereo or Dolby Digital or DTS or whatever is made at the point of decoding, not the original digital source (the optical output of your computer).

The optical TOSLINK output from your computer is no different from optical output on the back of a DVD player, Blu-Ray, DVR/cable box, TV, etc.

It's the playback stage where the decoding of that digital signal and digital to analog conversion occurs. The selection of stereo or 5.1 on a typical sound card in a computer is occurring at that playback stage (and going to analog amplifiers, speakers, headphone jacks. Basically the sound card is a little miniature home theater receiver and would have to be Dolby Digital licensed to decode Dolby soundtracks.

 

[gopher1369]

What the issue with the original replay was that "optical cables are only designed to carry stereo", optical can do surround sound, just not in all situations. Maybe a "in many cases with onboard audio cards." at the end of that and it's all good

You make some fair points, so let me clarify exactly what I mean. Optical cables were originally designed to carry an uncompressed stereo audio signal only. They were never designed to carry 5.1.

Dolby Digital and DTS were developed later as a way of compressing a 5.1 audio signal enough that they can fit down a stereo optical cable. Essentially, they are a bodge.

Anything already recorded in Dolby Digital or DTS will fit down an optical cable, the obvious example being a DVD as you correctly note. But PCs don't generally support Dolby Digital, most PC audio is uncompressed PCM audio so everything else will be carried in stereo, again as you correctly say, this includes games, it would also include Blu Rays (which generally use uncompressed 5.1).

It is possible to capture PC audio and compress it into DTS or Dolby Digital on the fly, but the license costs from Dolby/DTS are quite high and so it's only found on higher end sound cards (it's called Dolby Digital Live and DTS Connect respectively). The cheapest card I am aware of that supports it is the Sound Blaster Xfi series and the Asus Xonars.

 

[hwc1954]

Dolby Digital and DTS were developed later as a way of compressing a 5.1 audio signal enough that they can fit down a stereo optical cable. Essentially, they are a bodge.

I don't think the compression used for Dolby Digital and DTS was aimed as much at the bandwidth of optical cables as it was the bandwidth available for soundtracks on film soundtracks, DVDs and television broadcasts. We aren't talking about tiny MP3 files with crappy sound. The bandwidth for Dolby Digital and DTS recordings is quite high. Given the duplication in the signals in five channels, the small amount of compression is unlikely to produce much of a performance hit. Especially because the dynamic range of the DD and DTS specifications is enormous. Much higher, for example, than compact discs.

 

[gopher1369]

Sure, you're absolutely right, apologies, DD and DTS were absolutely developed for cinema/film first, then later used for DVD/optical/TV. Hands up, I made a mistake on that one.

I absolutely agree with you, in practice the difference between MP3, DD and CD audio is imperceptible. I quite like reading articles from audiophiles who insist that they can hear a difference, then refuse to undergo a double blind test to prove it, they're quite hilarious!

 

[hang-the-9]

Sure, you're absolutely right, apologies, DD and DTS were absolutely developed for cinema/film first, then later used for DVD/optical/TV. Hands up, I made a mistake on that one.

I absolutely agree with you, in practice the difference between MP3, DD and CD audio is imperceptible. I quite like reading articles from audiophiles who insist that they can hear a difference, then refuse to undergo a double blind test to prove it, they're quite hilarious!

It depends on the MP3 encoding used. Past 128 bit it's harder to tell, I think 192 bit mp3 done with a good encoder like LAME is when even critical listeners with good headphones could not tell an MP3 from a CD. When I rip my disks to the computer, I use 192 bit, it's a good compromise between the best quality and size.