SPDIF Connection

[Gabriel Torres]

There has been a new article posted.

Title: SPDIF Connection
URL: http://www.hardwaresecrets.com/artic...at=audio&id=82

Here's a snippet:
Many users and technicians must have already noticed that CD-ROM drives have an output called SPDIF and many sound cards, especially the more expensive sort, also have a connector labelled SPDIF. But ...

Comments on this article are welcome.

[Cee Jay]

I am no expert in digital audio connections, but after reading the S/PDIF article, i was left speechless. Is not S/PDIF a two channel digital audio format, as opposed to the digital bitstream audio that is supplied as the standard black or orage connector on the back of home theater receivers/DVD players, etc?

My dillemma is this. I have 6 JBL studio monitors and two monitor subs, all with one S/PDIF input and one output each, among others, such as analog and AES/EBU(digital XLR). I want to connect them to some sound card to have surround audio from a PC. I first (without having learned about S/PDIF) tried connecting the digital output from the DVD player to the front left speaker, then daisy chaining them all around to the other speakers via S/PDIF inputs and outputs. Uhhhhhh.....no way. Didnt work. The best that I could get was stereo.

After much investigation and research, I learned that S/PDIF is only a digital pair, and carries only two signals, say a left and right, a center and sub, rears, etc. Not all of the surround signals could be transmitted through one S/PDIF cable.

I then learned that you need MULTIPLE S/PDIF outputs, usually 3 of them, assigned as L/R, C/S, RL/RR. VERY high end equipment such as the Meridian G61R pre-amp have these, but those cost 8K and up.

So........how to connect these speakers to a PC. I need multiple S/PDIF outputs. Your article suggests that the "orange" outputs are S/PDIF outputs, but they carry more than a digital pair of signals. They carry all of the channels, no????? Is there not a difference?????? Help please.

[Cee Jay]

ANYONE??? Can anyone help me with this?

[Gabriel Torres]

Hello Cee Jay,

Sorry about not answering you before, for some reason I didn't see your original post.

Originally Posted by Cee Jay

I am no expert in digital audio connections, but after reading the S/PDIF article, i was left speechless. Is not S/PDIF a two channel digital audio format, as opposed to the digital bitstream audio that is supplied as the standard black or orage connector on the back of home theater receivers/DVD players, etc?

Both are the same thing. SPDIF is the name of this digital connection you are talking about; the black connector you mention is probably the optical connector (Toslink) and the orange connector is the coaxial connector.

Originally Posted by Cee Jay

My dillemma is this. I have 6 JBL studio monitors and two monitor subs, all with one S/PDIF input and one output each, among others, such as analog and AES/EBU(digital XLR). I want to connect them to some sound card to have surround audio from a PC. I first (without having learned about S/PDIF) tried connecting the digital output from the DVD player to the front left speaker, then daisy chaining them all around to the other speakers via S/PDIF inputs and outputs. Uhhhhhh.....no way. Didnt work. The best that I could get was stereo.

Of course it won't. The digital connection will carry a bitstream representing all the six channels. You will need to either find a way to configure each speaker to "tune in" to a certain channel (i.e. find a way to configure speaker 1 as front left, speaker 2 as front right, and so on) or to use a some sort of device to make this separation for you. If you post here the exact model you have I may research this for you.

Originally Posted by Cee Jay

After much investigation and research, I learned that S/PDIF is only a digital pair, and carries only two signals, say a left and right, a center and sub, rears, etc. Not all of the surround signals could be transmitted through one S/PDIF cable.

This is not correct. This connection will carry all channels available. Otherwise a single SPDIF connection between a DVD player or Blu-Ray player and a home theater receiver would only play stereo and you would need three wires, which is not the case (only one is needed).

Originally Posted by Cee Jay

I then learned that you need MULTIPLE S/PDIF outputs, usually 3 of them, assigned as L/R, C/S, RL/RR. VERY high end equipment such as the Meridian G61R pre-amp have these, but those cost 8K and up.

As explained, the problem is that you need to find a way for your speakers to "catch" the right signal from the digital stream. If they do not have a configuration switch on themselves to configure each one of them as front left, front right, rear left, rear right, the only way is by installing a device like the one mentioned. Probably your speakers do not have such configuration because they are intended to work under stereo mode only.

Originally Posted by Cee Jay

So........how to connect these speakers to a PC. I need multiple S/PDIF outputs. Your article suggests that the "orange" outputs are S/PDIF outputs, but they carry more than a digital pair of signals. They carry all of the channels, no????? Is there not a difference?????? Help please.

Explained above.

From all you posted it seems that the problem is with your studio speakers: they were designed to tune in only to the front left and front right channels only, because they were projected to be working only on a stereo environment, not on a 5.1 config. If you post the exact model we can download the manual and take a deeper look.

Cheers,
Gabriel.