View Full Version : Optical vs. Coax (Any technical expertise)

11-11-2001, 10:57 AM
A good question just came to me. I was wondering if anyone knows how much better a optical cable is better than a coax cable for digital audio. I'm a computer engineer, so I was forced to study digital signals, and I'm still a bit confused. The whole purpose of a digital signal is that it is either high, or low. So, if the signal picks up some noise, it doesn't affect the signal in such a way that the decoder cannot tell if it is a high or low signal. I would think an optical cable would be better because you have no impedence issues, and a faster data rate (although this is dependent on your system, I don't think receivers send the info faster on fiber than coax.) Either way your sending a bunch of 1's and 0's across a wire. Does anyone have any thoughts on this, or read some technical papers on the subject? I'd be interested in hearing your thoughts.

11-11-2001, 12:31 PM
I am a Manufacturing Engineer (I took a few classes on Digital Systems, Circuits, and Electronics). I am by no means an expert.

From what I have heard and know...The signal carried by the fiber cable is a cleaner signal, for the reasons you've already mentioned. However, the processing required to "change" the signal from light to data is higher than it is in coax systems. Therefore, the general opinion among High-End Audio Techs is that coax digital systems sound more full, and deeper.

So you are right, the signal is cleaner with optical, but that doesn't mean that the end result is better. I am sure that if you put a high end optical decoder up against a low end coax decoder, the optical quality would surpass that of the lower end system. But on comparable systems, chances are, you will like the sound out of the coax system just "a little" better.

You pose an interesting question though. Maybe some who is a real expert can give a better answer then me....


11-11-2001, 01:10 PM
I too am no expert but I'm a member of may home theater boards and this question gets asked a lot. From what I've read there is no difference in the sound of an optical connection and a coaxial connection on any decent receiver. The differences between the two cables are an optical cable is easy to damage, does not pick up interference from power cords and is expensive where as a coaxial cable is difficult to damage, does pick up interference from power cords and is cheap. Most people I know go with the optical because behind most HT set-ups lies a rats nest of wires, so they go with the optical to avoid interference. If someone is hooking the XBox up and can avoid having the line running through a maze of wires I would go with the coaxial cable because it's tough and cheap.

scarecrow kfj
11-12-2001, 12:18 PM
I perfer the opt.. It tends to break the sig up better in my reciever. It might be easier to damage but how hard is it to damage behing a tv/ entertainment center. I tried both with my old P2 and opt is def what I liked better.