Carnifex

Is there any difference between digital optical and digital coaxial connections in terms of quality?

joshd2012

Optical uses Fiber Optic technology. It is better in quality and performance. If you have a choice, always go with optical.

Carnifex

That's all well and good. But the thing I'm not sure about is why a receiver would have more trouble distinguising '1s and 0s' coming from coaxial cable than from an optical cable.

I can understand that optical cable does send a stronger signal, but how can a coaxial cable possibly lose enough signal that a receiver doesn't pick up all of the '1s and 0s'? If you catch my drift . . .

joshd2012

The biggest and most important difference is the medium. Coaxial travels over a metal wire which can lose signal strength and information on the way. This is minimalized by buying higher quality coaxial cable from companies such as Monster Cable. Optical, on the other hand, travels through thin rods of flexible glass. This glass is extra pure so there is an extremely low amount of impurities (something that can not be achieved in coaxial cable). The signal gets to the source stronger and with more of the information in fact (extremely close to 100%).

You have to remember that these receivers can process information very fast; so fast that the difference in time to process coaxial and optical signals in negligible. Since the processing time doesn't matter, you have to go with quality and that is where optical comes way above coaxial.

Carnifex

What would happen if a small part of a digital signal was lost through a coaxial cable, which was, for example, the information needed to tell the decoder to send one sound wave to the centre channel, and another sound wave to the rear left channel?

Would this cause the world to fold over and implode into itself, or would the reveiver simply just wait for the next instruction, with maybe a slight glitch or something?

Or do I simply have no idea?? Maybe I should take up knitting.

Aghama

The main differences are that optical costs a lot more and is more fragile. If anything, coaxial has less jitter than optical, but you're not likely to be able to tell a difference.

X

I agree. It's generally acknowledged that coaxial is less prone to jitter and affecting the sound than optical. I would only use optical if the components only had it for their input/outputs (no coaxial interface), and if the signal were travelling a very long distance where EMF would be a consideration.

RandyC

Optical is better when you are transmitting top secret military data.

X

I guess you have a point there.

joshd2012

I find that I get a huge difference in sound quality when using optical as compared to coaxial. If you are running your audio through a TV, I would say it doesn't matter, but if you have invested your money in a nice receiver and speakers, you will be able to tell a difference in quality with an upgrade to optical.

As for lost information, I don't know what the receiver does. I'm pretty sure it doesn't lose enough to kill effect a speaker. I think the only thing you will lose would be sound quality.

RandyC

Perception often matches expectation more than reality when using subjective non-scientific test methods.

As it is, I have a nice receiver and speakers and the coaxial and optical inputs sound the same. Engineering data as I know it would also suggest that the digital data stream is not affected by the method of transmission.


But like I said, I will design in optical for classified military applications.

My 2 cents.

Kevlar

Sound quality is the same so coaxial is the better choice
for a number of other reasons.

Optical connectors are prone to pitting and scratching,
even dust can block the signal. Micro bends in an optical
cable will cut the signal out also.

Coaxial is much more secure at the connection points. I
cant count how many times the kids have pulled the
5.1 optical from my PS2. They have never managed to
pull the coax from my DVD. If you have a sony unit you
are stuck with optical, if you have any support for coax
use it first. Signal quality is identical and coax is alot less
prone to losing signal from all the reasons listed above.

Plus its cheaper.

-K

eedoon

That's odds... some of my friends, which happens to love music and have some high end audio sets prefers coaxial than optical. They says, the sound quality is better than optical, which they claims to be "thin".

Aghama

That's a bit like saying jpegs transferred over 10BaseT look better than over 10Base2.

drmoze

Josh, your statement is *so* wrong, so I feel the matter needs to be set straight for the benefit of readers of this forum. First, there is no distinguishable difference between a properly hooked-up optical or coax audio line. Even with high-end audio equipment. The only concern is that an optical link is more prone to problems if the cable gets bent or kinked at any time. Coax cable is nice and flexible, less prone to damage.

The data is *digital*. The signal strength is not an issue at all. There is plenty of signal strength for coax bitstreams, and (get this) the loudness and frequency response of the audio track are unrelated to the strength of the signal. The signal is not "lost" at all, although an optical cable is more likely to lose signal if it becomes stressed or if the optical emitters/detectors and ends of the cable aren't clean.

Further, the "purity" of the cable (optical or coax) is completely irrelevant. That's comapring apples and oranges: one is a bitstream sent as light pulses, the other is a bitstream sent as electrical pulses. Either cable is perfectly capable of reliably delivering its intended signal format.

Josh, if you have degraded sound when using a coax conenction, the problem is likely with your "nice" equipment. And Monster Cables are primarily a marketing gimmick and a waste of money, especially with low-level signal connections between components. (If you still believe the hype, get a PhD in materials/metallurgy and then talk to me. $^)

Bottom line is, whenever possible go with coaxial. Connectors are cheaper and the connection is less prone to damage and glitches.

jumbojp

Here's my story:

I hooked up my DVD player with coax and optical at the same time a few weeks back.

The optical went to the DVD input and the coax went to the CD input on my receiver.

Using source cd's I knew well I then switched my receiver between inputs(using all the same settings of course) and noticed very little difference, but there was a difference.

The optical seemed a touch brighter and the coax seem a bit more mellow, but not enough to even notice if you weren't switching back and forth.

So for my system which is a tad bright using a Denon 2802 and Paradigm speakers I prefer coax a bit over optical.

Of course this could all be a cable issue since the optical was a cheap cable and the coax was Kimber PBJ

Mr. Salty

I don't understand part of this post. What does running the audio to the TV have to do with the difference between optical and coax connections? If someone is running audio just to the TV, they won't be using digital connections at all, optical or coaxial either one. It's a non-issue.

Josh, if you hear a "huge" difference between optical and coaxial, then I'd suggest there is something seriously wrong with the coaxial sections of your DVD player or receiver. If there are audible differences at all, they will be almost unnoticable.

I have used both optical and coaxial connections and could not hear a difference. From now on, though, I will use coax whenever possible because the cables and connections are more robust. Not only are optical cables themselves (which are usually made of plastic, by the way, not glass) more fragile, the TOSLink connectors used by DVD players just aren't very secure.

Carnifex

I've been told that when spending money on an audio system that at least 15% of your budgeted money should be spent on the cables. (For example, if you want to spend $2000 on your system, $300 should be spent on the cables!)

Is there any benifit in spending huge amounts of money on the cables? Is an expensive cable going to send digital data better than an inexpensive cable?

X

Here are a couple of things that might interest you:

http://www.digitaltheater.com/pictur...vs- Coax Cable


http://www.smr-archive.com/forum_6b/messages/421.shtml
"About 3 months ago, a team on another forum ran a 2 hour test where they connected a DVD Player to a Pre/Pro using a piece of coat hanger wire. The results after 2 hours of continuous operations – not a single error do to waveform degradation or timing inaccuracy. They made these measurements using equipment supplied by Dolby. Therefore, don’t get caught up in the marketing hype. Use a 75-ohm coax cable; it is less expensive than fiber (TOSLink). In fact, if you happen to have one of those cheap RCA/RCA cables (i.e., the ones with the yellow plugs on each end) lying around, this will work as well as a $100 cable and probably as well as a good grade of coat hanger wire."

joshd2012

Wow - I took a beating here, so let me try and reply to all post at once.

drmoze - The medium which the information is sent is completely revelant. The best conductor of electricity is gold. Therefore, any other metal used is less conductive and therefore more prone to problems transmitting the signal. Unless you buy cables completely made of gold (or a gold alloy), then you will have some signal loss and resistance. All wires have some internal resistance which will cause a signal loss. This loss may be minimal and relatively unnoticable, but it is still there.

As for Monster Cable being a hype. It is very simple to tell the difference before and after installing there equipment. So simple, that to deny the improvement would be ignorant.

Mr. Salty - The point of saying going directly into the TV is for people who use there TV's internal speakers or inexpensive speakers to listen to audio. I would agree that there is no difference for them because of the inexpensive equipment.

As for the statement on Optical Cable are made of plastic is junvenile. Optical cables are made of thin pieces of highly pure glass. If you don't agree with me, go read. Any statements made by you on this matter are null and void by this comment.

To Everyone - Try being responsible owners. If you complain about the fact that Optical Cable is fragile, you are not a responsible owner. I connected my Optical Cable years ago and it hasn't been touched once since then. Why the hell would you leave cable of any sort out where it is prone to damage? When I spend good money for cables, I'm not going to leave them where then are prone to damage, I'm going to put them somewhere where there is no chance of them being harmed. If you complain about the fact that the connectors are dirty, try being responsible. If you have any respect for your equipment, then you would keep it dust free and not continually remove the optical cable.

I think that is it. Optical cable is technically better than coaxial, which is why a lot of receivers offer 1 coaxial and 2+ optical. Optical is the future. Optical information travels at the speed of light which is faster than coaxial could ever travel.

joshd2012

YES, god yes. Spend money on good cables and you will beable to reach the full potential of your equipment. Think of it this way, recording studios use cable which is over $10 a foot (I know, cause I bought some). Why would they spend all that money if they could just use cheep cable? Because there is noticable difference. Cable is the messanger of your system, make sure you have quality cable.

X

This is going to be interesting. I thought run-of-the-mill optical cable was plastic too. I'd sure like to know the truth. And that takes references for me, not just someone's say-so.

joshd2012

Proof:

http://www4.nas.edu/beyond/beyonddis...r?OpenDocument

I can find another if you want, but I think this should prove to be enough.

Aghama

Uh, yeah, glass fiber optic cable exists, no one was refuting that. However, almost all Toslink cables use plastic.

joshd2012

I was unaware that this was true. Seems to me it would be worthless to pay money for plastic fiber-optics when they are only intrusted for transmissions restricted to feet.

http://www.aboutfiberoptics.com/facts.htm

I can assure you that I have glass optical cable. This could be the reason why my arguement is not being heard. I'm going to take a shot in the dark here and say that everyone who is disagreeing with me is using the plastic optical cable, right?