Digital coaxial cable

I’m wondering whether a digital coaxial cable is physically the same thing as a composite or component cable? There are different schools of thought with regard to this matter, which is why I’m posting here to see if anybody can provide any clarification, or better still, links to a reputable site that explains all this. Searches on Google yielded less than satisfactory results.

Opinions differ, but so far I gather that “yellow” (composite), “red”, “green”, and “blue” (component) video cables are all 75 Ω coaxial cables capable of delivering the same signal as an “orange” (digital audio) cable. Some people claimed, however, that analog audio “red” and “white” cables may vary in impedance and may not be suitable for the digital signal. Is this true? Or is any RCA cable the same cable?

If anyone can correct or confirm this information, it would be much appreciated. I suppose the simplest answer would be to “try it out and see”. The thing is, I would like to sort all this out before purchasing my receiver/speakers. - seems to cover most of it.

Cheap audio Red/White, or red/white/yellow for audio with composite video, are unlikely to be matched impedance, though in a short cable matching is not as crucial as in longer runs. Bootlace cable with moulded connectors and no strain reliefs is not a sign of quality!

Higher grade red/white/yellow sets may use 75 ohm high frequency coax, an example I found.

They also have a component plus stero audio (5 RCA) bundle - wish I’d been able to find that style when I needed it, had to buy the video and audio cables seperate - much tidier as a 5 way.

There are 3 basic grades of cable:

The lowest grade is poor quality and possibly inappropriate type of cable, shoddiliy assembled. Often found in little hard to open plastic packets on a rack.

The next grade has impedance matched cable with adequate screening.

The final type emphasizes the perceived merit of whatever feature the manufacturer is plugging, but is extremely poor value compared to competent examples of a standard cable.