Audio connections for 5.1 speakers

I recently purchased some excellent Creative I-Trigue 5.1 surround sound speakers for my PC. Actually I have more than 1 PC, but only one has a Creative Audigy Platinum ex soundcard installed, which outputs to 5.1 speakers, via analog connections.

But, I also have another PC, which has built-in sound (Asus Soundstorm) which can also output to 5.1 surround sound, via analog connections.

And then I have a DVD-recorder, which I can also use to play DVDs. This has two digital outputs for 5.1 surround sound.

So, my ideal setup is to have each of these 3 devices be able to output sound to the 5.1 speaker set. But, is it easy? I searched Google and could not find anything suitable to make this work. I am surprised that I should be the first person to ever want to do this, surely others must have done it before, but so far I cannot find a solution on the Internet.

I have managed to get the DVD-recorder outputting to the 5.1 speakers. I used a TOSlink optical cable to link it to the Audigy’s external box with various inputs and outputs on it, using the optical in socket. That works fine, and now when I play a DVD, and have the PC on, and not playing any other sounds on the PC, I can put the sound from the DVD through the PC to the 5.1 speakers, giving true 5.1 surround sound (if there is such an audio track on the DVD itself, of course).

But to connect PC2 to PC1 or directly to the 5.1 speakers is not so easy. I bought a coaxial SPDIF cable, as PC2 has an output for this. And the Audigy box has SPDIF input, with coaxial sockets. So I connected the two. However, I am not getting any sound on PC1 coming in from PC2.

I wonder what the solution is, and if anyone reading this might know. If you do, then please add your comment to this blog to help me out here.

Alternatively a switch box to switch between the 2 PCs, switching all 5 channels at once, would be great, as that would allow sound to go directly to the speakers from either PC at the flick of a switch. But so far such a device has eluded me in my search of the Internet.