Newsgroups: rec.audio.tech
Subject: Re: Carrying audio signal - only have 1 coaxial
References: <[email protected]>
"Mike C"  writes:

> I need to get audio from my sound card to my media closet. I have only
> 1 coaxial in the wall between the 2. My soundcard has line out and
> SPDIF connectors. On the other end, I have only RCA-type left and right
> input jacks (like on a standard receiver). My questions are:
> 
> 1) Can I carry the SPDIF signal on the coaxial and then use a converter
> to make it an analog audio system passable to RCA jacks? 

Yes. 

> If so, what converter/adapters would I need?

You need an extern D/A converter that connects to the SPDIF interface. 
There are external boxes that can do this. And practically 
all modern home theater amplifiers have this kind of feature 
built-in (S/PDIF input in them).
 
> 2) Can I carrry the line-out signal on one coaxial?  How would I do
> that?

You can only carry one audio signal through one coaxial cable. 
 
> 3) I know I can modulate the signal to carry it on the coaxial and
> de-modulate to L&R RCA jacks on the other end. Will this result in poor
> quality audio?

If you do it with very expensive equipment, you can do this 
at good quality. If the equipment needs to be reasonably cheap, 
then you need to accept noticeable quality loss.. 
One possible solution for stereo signal to one coaxial is to 
use stereo FM modulator and normal FM stereo radio on other end, 
this gives you "FM radio" sound quality. 

There are also other kind of modulators and demodulators.. 
But those are normally special application devices, and are 
expensive (not mass produced for consumer markets). 

> It seems to me that if a coaxial (like for TV) can carrry stereo audio
> AND video, I certainly should be able to carry audio on one.
> 
> By coxial I mean standard cable used for carrying a TV signal. I am not
> sure of the proper term.
> 
> Thanks
> 

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/