Another coax cable question re. DVD audio

[tcontas]

I connected my DVD player's audio to a Denon Dolby Digital receiver by connecting a cable from the coax audio out on the DVD player to coax audio in on the receiver. Simple enough. However, I used a regular cable with RCA type ends instead of a special coax cable. The receiver indicates it's receiving and playing a dolby digital signal and I am getting nice sound out of all 5.1 channels. So my question is, is a dedicated (or should I say expensive) coax cable really necessary or will a simple RCA type cable do the same job, as it appears to be doing in my set-up? Maybe some receivers are better able to pick up the DD signal without super-duper coax cable than others? Am I missing something? Thanks in advance to any and all who respond with their pearls of wisdom.

[markw]

In fact, I'd say you've just picked up on something that saved you a lot of money, both now and in the future. You tried something before simply believing the hype and following the herd.

That is that it doesn't take a magic cable to pass digital the short distance needed in household environments. All it takes is a simple 75 ohm shielded cable with RCA connectors solidly affixed to the ends. In fact, in many cases even those 75 ohm and shielding requirements might be questioned.

[tcontas]

I didn't even use a 75 ohm shielded cable. All I used was 1 basic audio cable with RCA phono-plug type ends (like the kind that come in the box when you buy a cd player or a tape deck). I'm sure audio purists who believe strongly in the difference high-end cables can make will weigh in that this cable is sonically inferior, but I'm more concerned with whether I'm getting the true DD 5.1 signal. It appears I am getting it just fine and the sound is pretty darn nice. Thanks.

[markw]

A digigal signal is pretty simple and straightforward. It's either on, or it's off. And, there is error correction built in for those possible "hazy" moments.

I remember a post some time ago that pointed to a website where some guys used a straighetned out coathanger and got superb results.

[hermanv]

RCA cables come in three basic types:

1. Twisted pair - a pair or as many as 192 wires are twisted together to reduce 60Hz hum pick-up and routed to the two RCA plugs. Usually used for high impedance connections between audio components. High impedance means 47K Ohms for example.

2. Shielded: A conductive braid or foil covers an inner insulated wire. Very similar to coax but not a controlled impedance device - usually used for audio interconnects. In this case the shield blocks the 60Hz hum.

3. Coax: A controlled impedance cable consisting of an outer braid or foil and an inner conductor. The shield to inner conductor spacing and thickness are carefully controlled. Coax cables have huge bandwidths and thereby reduce jitter or time smear.

Although nearly any cable will work as you describe it, this is only true for short distances. A longer run of non-coax cable with a digital signal is likely to cause reflections and problems.

The yellow RCA terminated cables - video cables - are a form of coax. They can be had dirt cheap and should be used in this application.

People with mega buck equipment swear that truly expensive digital cables make a difference in their systems.