PDA

View Full Version : New TV Setup Question - Optical Cables


Rathji
12-28-2007, 10:15 PM
I was going to post this on the cheap HDMI cables thread, then realized it deserved its own. I got a new HD TV, HD Satelite Box, and a 5.1 sound system on Boxing Day. I initially did not realize the Sat box was DVI, so I bought the wrong cables from Memory Express and have worked it out with video component cables for the present time, while I order the proper cable from Monoprice.com.

Since I am placing the order, I am going to be replacing some of my older audio and/or RCA cables as well. During my setup I noticed an optical port on the back of my DVD Recorder and at least one other component and was wondering what is was used for? Is it Audio, Video, or both? and is it any better than what I am using now? There is no mention of it in any doumentation that I can see.

Right now I am using
- S Video/Digital Audio Coax from DVD player
- (soon to be) DVI-> HDMI Cable / Digital Audio Coax from Satellite Box


Clearly I am out of date on this stuff since before this new setup I have never used anything but Coax or Red/White/(Yellow) RCA cables.

Top Shelf
12-28-2007, 10:26 PM
Optical is just another connection for sound. From everything I have heard, there is no real difference between the quality of optical and the quality of coax. I believe optical is more immune to interference from power cables.

Running coax on your system should be just fine though, if you use coax now stick with it. As long as your receiver can handle the various coax inputs, you'll be golden.

Prototype
12-28-2007, 10:50 PM
Optical is just another connection for sound. From everything I have heard, there is no real difference between the quality of optical and the quality of coax. I believe optical is more immune to interference from power cables.

Running coax on your system should be just fine though, if you use coax now stick with it. As long as your receiver can handle the various coax inputs, you'll be golden.

I don't know how optical can be 'more immune to interference' when it's based on light. The only knock I've heard on optical is that the cord has to be relatively straight, some bend is ok, for it to work properly. Any twists and turns and you lose the optical.

I could be wrong about the interference.

Rathji
12-29-2007, 08:45 AM
Well it makes sense that it would be immune to electrical interference, I never thought of that. If it isnt going to be any better than the cables I have then I wont waste my time unless I will run out of inputs.

Thanks Alot!

ken0042
12-29-2007, 10:16 AM
Optical is just another connection for sound. From everything I have heard, there is no real difference between the quality of optical and the quality of coax.

Just to be clear here for the OP, by "coax" we are talking about a 75 ohm, "really thick" RCA cable.

Not the kind of coax that Shaw TV signals run through.

Top Shelf
12-29-2007, 10:18 AM
Hey Prottotype, the below is from Audioholics.com (http://www.audioholics.com/education/frequently-asked-questions/optical-vs-coaxial-digital-connections). Like I said, it is a heavily debated topic. Just google optical vs coax.



Q: Between optical and coaxial, which connection is going to give the better sound quality, and why?
A: " Better" is relative. In a harsh environment, optical may have advantages. By "harsh" I mean:
Cable runs over 10ft
Cable runs in close proximity to video and power cords emanating RF noiseIn most cases, the above conditions would result in negligible impacts on the signal quality since the signal being transmitted (PCM or bitstream) is sampled at low frequencies (44-48KHz) and thus are more immune to noise impairments.


However, using optical cables can minimize the potential of the above mentioned problems and thus may help to reduce common mode noise. The only negative about using optical cables is the connection is not always as secure as a coax (http://www.audioholics.com/FAQs/000705_optical_coaxial.php#) one, and can sometimes be compromised easily by moving components frequently. In addition, optical cables are usually more expensive than coax ones.


Bottom Line: Using optical cables for your digital connections may help minimize susceptibility of coupling RF noise into the line and reduce loss for long runs (10 feet or more). However, optical cables tend to be more costly and sensitive to abrupt external forces, which may potentially weaken the connection over time. In any event, either connection method should yield excellent and comparable results in most cases.

Prototype
12-29-2007, 10:37 AM
From my experiences with optical it's been just that... good, but you want to be careful with them. They aren't the most durable method, that's for sure.

I think in this situation, it depends on what you want to do. If you're doing a theater room and want the best of the best, top o' da line... I'd say you should be concerned with what you're using.

Me personally... as a Radio grad from SAIT... have never been that picky with my audio. I do perfer a surround sound set up over TV speakers, but as far as the connections go... I've always used RCA. Never needed anything more.

But I will agree that if optical is the way you're going, that you should be ready to spend more than other options.

Old Yeller
12-29-2007, 11:14 AM
I bought a 6' optical from monoprice and had no probems... good quality cable.

I never realized there was an optical vs coax debate, I always just assumed the better choice was optical, interesting.

BlackArcher101
12-30-2007, 01:26 AM
I don't know how optical can be 'more immune to interference' when it's based on light. The only knock I've heard on optical is that the cord has to be relatively straight, some bend is ok, for it to work properly. Any twists and turns and you lose the optical.

I could be wrong about the interference.

I've got tons of twists and turns in my optical (toslink) cable and works perfectly. The only think you can't do is kink it or else a crack may break the connection. It works on the basis of fibre optics which are actually very versatile. Regarding the interference, I think others are referring to the induction of current in wires from exterior electric/magnetic sources. With toslink, I don't believe this is possible due to the transmitting medium being non-metallic.