Analog RCA cable work as a Digital Coax cable?

Question

Just thought I'd try it, id never specifically use an RCA cable to replace a digital coax. Well I heard that the rca would be able to work just as well as the digital coax, so I tried it out. I was surprised it did pick up the sound, but was only in Pro Logic II, not dolby digital. Is it how I thought that you still need a digital coax cable, or am I doing something wrong or dont know something everyone else does?

Answer 1

    You are correct, RCA cable doesn't work if you want your audio source decodes DTS or Dolby Digital 5.1 sound.

Answer 2

You want to use the VIDEO cable, not red/white cables.

The SPDIF calls for a 75 ohm coaxial cable because all video cables are made with this. These are usually marked with a yellow band on the RCA plug.

Audio RCA cables can be made with 50, 75, 110 or 300 ohm coax. As long as both the left and right are the same - it does not matter.

But the higher frequency video and coaxial-digital signals want a cable that matches the input jacks and these have been standardized to 75 ohms.

YOU CAN USE THE WRONG CABLE

Sometimes the red/white cables are made with 75 ohm coax so they work fine.  Even when the coax is wrong - the audio appears to work.

But - using the wrong cable causes the sound to drop out. Sometimes it is every 15 seconds, other times it is once every 10 minutes.  When people have this problem, switching to a VIDEO cable or a "coaxial-digital" cable solves the problem.

Answer 3

Actually if you use the multichannel in and use the 5.1 - 7.1 inputs directly you should have superior sound. So anywhere from 3 to 4 RCA sets.

Or some equipment has a XLR set of the same which will offer even better sound.

Edit: Apparently I was unclear in my answer. I was referring to the uncompressed analog outputs from a source device. These will always be superior to any digital format as there is only one DAC at the source. Remember audio is ANALOG not digital. I want to thank the inexperienced confirming my thoughts that some here like to pretend that they know what they are talking about but all you have to do is let them talk and it becomes apparent.

Answer 4

NO, that will not work. You need a Digital Coaxial cable. You can spend 30 bucks for 1 at Electronics Express, or 10 bucks for 1 at Wal-Mart. The 30 dollar 1 is better though, you will only notice the difference in the picture quality of the 2 choices (cheap or expensive).

Answer 5

The only real difference between a digital coax cable and a RCA cable is that the digital coax cable is a RCA cable guaranteed to be meet the requirements of the digital coax spec.

In other words, it's just a RCA cable.  Granted, a slightly higher quality RCA cable.  As you suspect, SOME RCA cables will work just fine as digital coax cables.  In fact, that's what I'm using right now - the video cable from a $10 composite cable kit.

Works fine, and definitely cheaper than a $20 no-name brand digital coax cable from the same store (to say nothing of the $50 Monster brand cable...bleah.)