Coaxial Digital Connection Vs Digital Fiber Optical Connection?


H Friends

I have been wondering since I bought AV receiver a month ago that

1. What is the real difference between Coaxial Digital Connection and Digital Fiber Optical Connection?

2. Which is latest and better? why?

Any real good information is appreciated!

They are both just different ways to send a digital stream from one component to another. The optical obviously uses light to send the information.
From most of the reviews that I have read compairing the two, it seems the majority of reviewers felt that Coaxial delivered a warmer richer sound than the optical. I'm not quite sure how this is possible, but I have read it on more than one review.

I know for a fact that an optical cable is a lot easier to damage, and thus ruin, than a coaxial.

use the optical cable. there is better frequency response within the fber than within copper.

How could frequency response possibly make a difference on a digital cable? What an unbelievable statement! Do you have any idea what constitutes a digital data stream?

I recommend coaxial for the reasons mentioned above, it is simply more rugged and provides a more secure attachment at either end. But really, it isn't worth the time it takes to fret over it.

Rick Z
Long runs of optical cable, over 6 feet, can be subject to internal reflections leading to some data degradation. Most systems have enough error correction to deal with this anyway.
To my ears optical and coax sound the same.

My personal opinion is that the coaxial is better for sound. However, the quality of optical cables are more consistent in terms of the amount of data they can handle.

Having used an optical connection for my xbox and a digi-coax for my DVD player, I must say that I think the coax is the better cable . It sounds JUST EVER SO SLIGHTLY richer. The difference is not so much that anyone would REALLY notice except for COMPLETE AUDIO-PHILES. Also it does feel much more durable than an optical cable .

When correctly connected, Coax and Optical should be exactly the same. Bandwidth isn't and issue, error correction (when connected correctly) isn't and issue. Distance, say over 50 feet might lean toward optical but who does that? Optical cables can be miles long compared to copper's hundred of feet for the same amount of signal loss. Optical cable can be fragile and cannot be taken around corners too tightly or pinched. For all intents and perposes though, it doesn't make a difference which one you use.

Now, having said that, there are a couple of situation where one MIGHT be better than the other. They both fall under "defective equipment" though.

1. The CD data, though optical, is converted to a electrical signal. To create an optical signal, this elctrical signal - essentially the coax signal, has to be convered to optical by a laser-diode. You could theorize that am optical signal could not be superior to a coax signal because it is derived from the coax signal. I would not worry about it though.

2. Optical connections do not carry grounds. In a pooly designed system an optical connection COULD produce less hum because there are fewer ground paths. The music to the decoder would not be any better but a crappy amp could add hum to an otherwise pristene music signal just before it got to the speakers. This hum would be faily obvious though.

Again, if you have good equipment, use either one.

Since we're talking about DIGITAL signals, signal degradation is not an issue within the cable. When any "1" or "0" would get corrupted within the datastream, through either optical or coaxial cable the whole audio signal would be deteriorated for a short amount of time. Therefor things such as warmer sounds are a total illusion. Those things wouldn't make it through a double blind test. I read various forums and they all start explaining about the wunderfull metalurgical properties of coaxial, but that's totally irrelevant for digital signals. Please point me to a study that proves otherwise.

Yea I don't think in lab conditions that there could possibly be a difference. As puma stated disrupting a stream of digital data would not create something like a warmer tone? I guess I'm wondering what that would come from... more 1's? more 0's? I'm just thinking that there is no possible way... I personally run co-axial when I can. But not for really any good reason. With a well shielded cable I don't see how you could think there's a difference... just kinda like your DBS systems don't get "fuzzy" I don't believe that anyone can hear a difference between optical and co-axial digital signals...

Pierre Fon
It is all in the mind or in the ear!. I can understand your dilemna,as I went through the same process. Everybody (including so called experts) seems to say different things. In the end, my dvd solved my problem of choice - as it does not have a coaxial facility. And the sound is no different. As 'Puma' states: "it is just an illusion" It is what we want to believe, in a nutshell. Buy the cheapest one you could lay your hands on.

I don't believe it is in the cable, but rather in the conversion process to optic vs. electric.

If the converters are lousy on the optic end, then the coax might sound better, if the converters are decent on both ends of the optic route, then the optic may sound equal if not better due to it being impervious to RF's and grounding issues!

Chris Munson
Have recently done the coax vs optical cable test and did discover the coax cable better for the dynamics of a DVD movie.
The optical cable tended to be a little more detailed but lacked the punch of the coax.
This of course my observation and perhaps not all will agree.

Wanna hear a VERY nice comparison from a retail shop here in Singapore?
They said:
Optical cable is disadvantageous towards Coaxial, because high frequency travels faster than low frequency (true when it comes to sound) and so the high frequency "overtakes" the low frequency signal, thus arriving at the amplifier earlier and changing the sound significantly under some circumstances.

Now: did he try to bullshit me or was he just totally nuts?


Totally nuts. The law of physics will need to be changed from today for the Singapore storey to be true.

Tidan raises a valid point. data conversion could be a problem. Puma is correct we are only dealing with 1's and 0's, but a slight difference in time between the sender and receiver will change the characteristics of the sound from one sender to the receiver, hence Tidan's point.

IMOP, optical makes a better connection, but co-ax doesn't require the the extra conversion to an optical signal.

What is best, is what sounds best for you. Try both, it doesn't cost a lot to experiment and find your own preference.

Ok. Here is the skinny. Optical runs longer than about 25 ft are impossible. It is an LED light not a laser. As the signal is transferred, portions of the light can reflect back and forth within the cable. This causes jitter, a phenomenon unique to the digital domain. Jitter is a non linear distortion, a temporary fluctuation of the digital audio signal that it reduces dynamic range and clarity, while compressing the soundstage and significantly raising the noise floor. Jitter can be caused by poor construction of the cable or by vibration of the cable so you need a good cable with shock protection.
GM from OZ and Tidan are correct about conversion of the signal being the problem. the signal starts of as electical, is converted to light, and then back to electrical at the other end. Not so with coax. Here it stays as electrical from start to finish. So coax should be better but the equalizer is that coax cables are more susceptible to noise so you need heavy shielding. So if you compare a great quality coax cable like monster reference vs. a monster reference optical the coax should be better.
But if you can here a difference than you are a better man than me.

why do you guys car about durability? Its not like they need to go through rigurous testing and hold up abuse all they do is sit behind your stereo cabinet and send an audio signal. If you do really care then get high quality cables. I personaly think optical is better, I hear higher detail through it than my coaxial connections.

The frequency theory could be true cause 1's and 0's can be carried out through the use of frequency modulation which is one of many ways to send digital info.

Miguel is absolutly right. the optical cables goes thru an extra converstion elec - light - elec. this leads to jitter, due to extra conversion. i personally have optical cable but thinking of switching to coax, just to give it a try.

You people are all idiots. So what if it goes through another conversion to optical or not? It is still 0's and 1's no matter what. There is no "conversion circuitry" with optical... it is an LED at one end driven by the signal and a phototransistor at the other end which regenerates the signal immediately and directly from the incoming light. It's a conversion yes, but I wouldn't exactly call it a complicated circuit. If you get sound at all, it's working perfectly. Yes, there is a chance for a pop in your sound if there is an error, but it would take one hell of a bad connection to have that happen, and it can happen with either cable. So pull your heads out of your a$$es and stop trying to justify for yourself why you just wasted your money. There are two kinds of people in this world who will tell you they hear a difference: 1) very good salespeople who say some pretty convincing B.S. trying to go over your head with big words and electrical theory you probably don't know anything about, and 2) customers of the people from #1 who are too stupid to realize they got ripped off and are trying to justify for themselves that they hear a difference. There is a third kind, and these are the people that have too much money for their own good and want to buy the most expensive $hit even though they don't know why it's better than the $10 one in the other aisle. To their defense, I guess the cables DO look a lot nicer. Hmm, too bad I don't have people over at my house on a regular basis to compliment me on how my cables look behind the entertainment center...

I work at a major retailer of home audio/video and laugh every day at the people who want to drop all their cash on "awesome" digital cables. Spend the money on your analog interconnects and speaker wires, and even then don't go overboard. Take it from me, I'm off the clock. :)

if you are going to spend money...spend it on managing acoustics in your audiable difference unless you are a dog! If you are worried about this stupid debate, then your cables are worth more than your speakers...which means you are not a true audiophile, a wannabe, or full of BS. If you have managed room accoustics properly and have the right set of speakers (the 2 most important things for good sound)...YOUR CABLES DON'T MATTER!

Mike M
Hey guys, this is good stuff, especially Mike's editorial. I think he is right on about us so called audio/vedio files. I would say this though: I don't hear a difference, but Lower frequencies signals, LFE, keep falling off whenever I use coaxail over 15 feet. I'm guessig becuase of some type of interference, so I only use opital when I go over 12 feet, optical seems to work fine whatever the distance. Like one person said, the signal conduit just sits there so it doesn't have to be made of steel.
P.S. Mike, you editoral was funny as all get out. You should be have been a comedian. You missed your calling.

Every review I have read stated Coaxial Digital is better.

Mr. B.
Nice to hear the different opinions on optical. My $10 optical cable which has lasted me for over 2.5 years broke the other day. I had no problem with it until my friend came over with his laptop and surfed the net using his "WIRELESS" router. When I turned my DVD on, the sound became "choppy", "popped" a few times, then no more sound. I thought my DVD player broke, then I bought another DVD player and tried it again - both Optical and Coaxial. The Coaxial worked, but optical did not work, then thought it might be my optical input to the receiver (never thought the cable being an issue). I then bought a new optical cable to see if it really was just the cable which i doubted but hoped it was because to replace the Receiver would cost me over $1K (but how could a cable that just sits behind the unit just break?). In the end, it was the cable. Was it because the "WIRELESS" connection interfered with the light signal and broke it? I am no expert but it was a coincidence that it broke the moment I turned the DVD on when the "WIRELESS" internet connection was within 5 feet from it and was the first time wireless was ever in my house. Durability issues? Maybe certain frequencies of wireless routers affect the light in the optical or even in the DVD players? I would be interested in knowing if this has happened to any of you before but i would caution anyone trying to do this as your optical cable/DVD player may break like mine did.


The Sony home theatre package I recently brought recomends making the coaxial connection.They have also supplied a coaxial cable.

In my opinion optical doesn't pic up noise like the coax.Correct me if I'm wrong.I've tried optical it sounds slightly more cleaner.But I don't know why Sony recomends coaxial.

Most Sony equipment, including Minidisk, comes with Optical. That's why they recomend it.

Tim,who I think would know a little bit about digital audio connections say.

"If your system components allow you to choose between two types of digital connector, note that both have identical audio performance. Under some circumstances, however, very long coaxial cables can be more susceptible to radio frequency (RF) interference than optical cables. Because optical cables are more expensive, try coaxial cables first and switch to optical only if you encounter problems."

So I guess the bottomline is, if it sounds good with coaxial, stick with coaxial. If you get too much interference, have the money to spend, or only have a digital output, then go with optical.

I agree that the only reason it seems for a difference is sound is either,
A. Interference, or the quality of the cable you are using.
B. The way that your reicever or audio source handle optical vs digital signals, i.e. electrical to optical conversion.
C. The power of suggesting is messing with your head.

Chris Lee
Just got a receiver/amp that accepts both digital coaxial and optical input. I got my spare video cable (that came with my cheap VCR - must be real low grade and cheap cable) and an optical cable. Connect the two to my DVD player and played my favourite CD. What a surprise at the sound quality - they both sounded exactly good! Actually, it was not a surprise as it would contradict what I've learned in my Electrical Engineering graduate class. As long as the connection is good, the 0's and 1's are not going to make any difference.

To those who said that expensive coaxial is better than the already expensive optical (or vise versa) in so many forums, they are probably Audio equipment salesmen.

I was going through the same confusion as everyone else on this thread.

So I did a head-to-head A/B comparison yesterday, as follows:

My DVD player (Pioneer DV-440) has both kinds of outputs. My home theater receiver (Yamaha RX-800) has an optical in for the DVD player and a coax in for a CD player, so I connected both simultaneously. Then, while playing a good quality audio CD, I simply kept switching between CD and DVD on my amp input selector. I did this over and over, at various volume levels, for almost 30 minutes.

My speakers are pretty good (JBL S-10), so I figured I would be able to hear a difference if there really was one.

The result? I found the coax produced a warmer sound. However, there seemed to some loss of clarity on the sibilant "S" sounds in the vocals. But the differences were EXTREMELY minor - I had to listen really hard.

Now I've got 2 contradictory theories to explain this:

1. The optical cable is better, because it reproduced all the highs without chopping off the extremely high frequencies. That's why I could hear all the "S" sounds and clasp cymbals a little clearer.

2. The optical cable is worse, since it distorts the highs, making them sound brighter, which I mistake as sounding clearer. Since the coax cable does NOT add this distortion, it sounds warmer.

So which explanation is correct? I need all your opinions on this to help me decide. I've been using optical so far (no-brand), and am wondering whether it's worth spending $25 on a good coax cable (like Monster), just for slightly better sound.

Of course, purely from the convenience point of view, it would be worth it, because I could then use the optical output for a direct connection to my mini-disc recorder, and the coax out to my amp.

What's the vote?? Thanks in advance for everyone's opinion.

Henry C
For those who have no tried out the difference between the two types of digital connection, please do so. For if you have not try it, you can't understand it. You can always return the cable you don't want and keep the one best works for you. To my ear, digital has more clarity than the coaxial, my surround speakers is more clear but the sound is so clear it is very forceful. When i switch back to coaxial, it is less precisie, and becomes more of a natural sound. The experiment I used was both medium grade monster cable. Try which works best for you.

Ok, i've read mostly all these comments... I can tell this is a very complicated topic that no one truely understands. I have a question for you guys. What kind of difference is there between using a regular composite cable for a digital coax. I'm assuming there would be no difference, I don't see why the stores really have to charge an arm and a leg for a special composite cable labled digital coax. Same thing for the component cables, I've also used regular composite cables as a substitute and compared results and couldn't make out any difference. Opinions, Thoughts?

The people that wrote there is basically no difference is 99.999% correct, as is the person that reprinted the paragraph on the statement from that they are really the same, except that RF signals can interfere with coax cable, particularly on long runs. As most, if not everyone, doesn't use these connections from their DVD or CD player for long runs it is a moot point.

It is like a computer. You have I's and 0's. If coaxial was different from fiber optics you couldn't even type a letter to your printer on a computer if the wire didn't transmit the info correctly. And that is crappy wire.

Remember--the most important ingredients in a sound system by far are your speakers, their placement in the room, and the room acoustics.
Obviously in a Home Theatre set-up the monitor quality is very important.

I agree with last post save to say that speakers are not the most important ingrediant to a sound system! You only get out what you put in! That is your input which includes your Record Deck, DVD, CD etc. and their connections are the most important as has been proved time and time again!

I think I know
In an analog system, noise will have a direct effect on the system. But in a digital system the effect of noise will only be a problem if the '0' are intrepreted as '1' and the '1' is intrepreted as '0'. There are a bunch of equation from my comms lecture to calculte the probbaility of these error happening. So the real question is which method has better noise rejection. But for for a short length of cable I dont think there will be much of a difference. If there are to much noise (to much misintrepretation of 01) the receiver will most probably doesnt recognize the dolby digital/dts () signal and could just take it as a pcm signal.

I'm gonna have to agree with Mike. Most of you "audiophiles" are so caught up in your own percieved intelligence that you lose sight of what is actually happening. As long as you're getting the signal, and it's not "choppy" on either optical or coax, you're fine. Otherwise they are the same. Ya know when cell phones and cable went digital? Interference went from "fuzz" to "choppiness", remember? It's very easy to tell when a digital signal on a cell phone is messed up, you lose sounds, not quality. Same with digital cable, ya know when you lose connection when the image gets all blocky or dissappears. So the same follows with digital audio connections. As long as the sound is not cutting out or get choppy. It doesn't matter what you use!!!!!!!! The "warmth" that some of you claim you hear on coax connections is your own sense of superiority. Here's some news audiophiles, god didn't make your ears any better than ours. Minus a few people with hearing problems, we all hear the same crap. The only difference is how much we pay attention to it.

SO TO END THE DEBATE.............unless you have lots of interference (from power lines, extreme rf signals, etc..) while using coax; or plan on tying you optical cables in tight little knots, IT DOES NOT MATTER!!!!! FOR THOSE OF YOU WHO DISAGREE...TAKE A BREAK FROM WORK AND GET AN ELECTRICAL ENGINEERING DEGREE FROM YOUR LOCAL UNIVERSITY, THEN YOU'LL SEE THE LIGHT!!!

I just discovered an interesting problem with my coaxial digital cable. Once a while, I noticed a short voice clipping (off for a second then on again) and the dolby digital light on my ONKYO DS-838 receiver went off and on again. This usually happened when the AC starts to run or we turned on a blow dry/drill,etc... It seems I have a lot of interference and voltage spiking problems.

I decided to switch from the coaxial to optical, and viola, the problem disappeared!

The question for experts, with that much noticeable interference from a voltage spike, do you think a basic Monster HTS1000 Surge Protection Clean Power Stage 2 would solve the problem? I currently just used a basic $30 surge protector. I wasn't sure the Monster Surge Protection would make any difference.

Thanks in advance for your comments.

How could I bye components to preppare optical mini plug or oprical rectangular plug by myself.

Couple of comments...

1) Optical is always a better media for transmission when cost is no object. There is simply no interference, and light travels faster than anything else. period.

2) This so called "conversion delay" is small or non-existantant. Both signals are converted into digital. Whether you convert to optical, radio, electrical, it doesn't matter, conversion is conversion for our intents and purposes (in hundreths of a milisecond).

3) When it comes to cables, it does matter. Yes, speakers are the most important, but there are big differences in quality of cables. Try comparing a monster cable to some crappy interlink or something. It makes a lot less difference when digital.

In computer cables the same goes. Computers and receivers are just passing digital data. Both twisted pair and optical are digital. Optical is faster transmiting, without interference, and reads the signal faster. Hope this helps

You said if u have good equipment u can use both, Will you consider Marants SR4300 with a Toshiba DVD good equipment?
Would appreciate an opinion from anyone?

Yes, Toshiba and Marantz is good equipment.

By the way, the photons in the optical cables travel at exactly the same speed as the electrons in a coaxial cables. Interference in a digital system should not be a factor. More than 50% of a digital systems signal can be distorted and it will still work with 100% accuracy. That is THE primary reason everyting is going digital.

Unless of coarce you don't have "good" equipment.

Hope this helps.

My CD's also have a 'warmer' sound when I stick them in some hot water for a few seconds before playing. But seriously, guys, it's digital. It's the same thing after decoding whether you transmit the digital stream thru fiber-optic cable or telegraph wire. That is, assuming, you don't have errors when it reaches the other end.

Forgot to add... If I let my DVDs sit around for too long, the video isn't quite as crisp.

Not gonna tell ya!

What are you on? Can you get me some?

I am on my couch. Visit your local furniture dealer :P

PS- Not on anything, just using my adept sarcasm skills.

"The question for experts, with that much noticeable interference from a voltage spike, do you think a basic Monster HTS1000 Surge Protection Clean Power Stage 2 would solve the problem? I currently just used a basic $30 surge protector. I wasn't sure the Monster Surge Protection would make any difference."

NOPE. Electricity is delivered to your components in AC and converted in every component (by a transformer) to usable DC current. Ergo, "conditioning" the electricity before it hits the transformer is a waste of money. The only way a line conditioner could conceivably work (and even then I doubt it) would be to crack open every component and install line conditioning after the electricity is converted to DC. But the fact of the matter is all transformers "condition" the electricity anyway.

That said, while I say "IXNAY" on the line conditioners I do recommend protecting your components with a good surge protector just in case---even though most good components have their own fuses and surge protection. Good surge protection is inexpensive and is worth the cost to give you peace of mind.

Coaxial is better. Mike is a dickhead to think that cables dont matter. DICK HEAD.

Billy, good reasoned argument there. Very persuasive.
[Hands sarcasm back to Alex]

From reading all this, it seems to me that the quality of a digital cable (coax or optical) will reduce the possibility of damage or interference, but will not change the nature of the sound itself. It merely ensures the 0s and 1s get through OK.

There appears to be a possibility of a difference over a long distance, where coax *may* be more susceptible to interference.

The connections and components used in the conversion of the signal into an optical signal may be responsible for some difference in sound. A few people have commented that the optical signal seems to be clearer for high frequency sound (eg letter "s")and a coax signal seems "warmer". This is possibly because some high-frequencies are not passed on through a coax, or because an optical conversion somehow gives them more weight or volume. Although both of those theories sound half-baked to me.

Most magazines I've read say coax is better. When I asked for an unspecified cable from my local Richer Sounds, they unhesitatingly gave me an optical cable (for the good combination of Toshiba and Marantz btw). Either one of those opions (or both) could have been based on hearsay rather than provable fact.

My recommendations:
Buy whichever you like, but get a decent brand/quality.
Spend about 10% of your budget on cables.
Be swayed by practical considerations, eg. optical doesn't go round tight corners; you might want to use your optical connection for a specific bit of kit.
Don't buy both to do a sound test - whichever you choose, you will always feel you are missing something.
If you really don't like the sound, then check your connections and setup, and only then consider changing the cable (hope you kept that receipt).
Finally - and this is important - hide it out of sight and enjoy your sound.

I agree with G-Man on the power conditioners. Your equipments' power supply SHOULD condition the power unless you have unstable equipment...

Regarding the Optical/Coax debate: I've tried connecting by DVD player and receiver with a 50 foot piece of bare, unshielded, solid core, cheap doorbell wire. Guess what? It still worked, even when I ran it around my TV and a florescent lamp.

The digital signal does not need to be clean to work -- that's analog that has that problem. Let go of the old rules.

I've connected the coax signal to an oscilloscope and it's a square-wave. For simplicity we will call it 1Volt. When it's high at 1 Volt, that's a "1". 0 Volts is a "0". As long as the voltage is above ½ a Volt for a certain duration, that's just as good as 1 volt. A quick spike above ½ Volt is ignored and is still a "0" because it wasn't above ½ Volt for the correct duration. I've inserted capacitors and a potentiometer in series and parallel with the signal and it takes a huge amount of tilt in the square-wave to cause distortion and loss of lock. I would imagine a wobbling CD or a poorly grounded amp would cause more distortion than the connecting cable. Three feet of cable is a cakewalk.

And don't think that optical cable has more bandwidth than copper. Regular copper wire is used in all types of amplifiers (like microwave) to the 10 GHz+ range with ease. AC-3 and PCM audio require less than 400 KHz bandwidth or 1/25,000th of the available bandwidth. Optical cable's advantage is distance not bandwidth. Three feet of copper is not what I would call "Long". Across the Atlantic Ocean is Long.

Finally, from my March 07th post "The CD data, though optical, is converted to a electrical signal. To create an optical signal, this electrical signal - essentially the coax signal, has to be converted to optical by a laser-diode. You could theorize that am optical signal could not be superior to a coax signal because it is derived from the coax signal."

Buying coax because it's the most prevalent connector for your devices makes sense. Buying coax or expensive "Digital" coax cable because it gives you a warm fuzzy does not.

A fool and his money...

I prefer to use coax to optical because it is a more rugged cable and not prone to optical cables sensitivity to being bent or squashed etc. A decent coax cable is only a few bucks but optical is much more expensive also. As far a sound difference there is none that I can hear. Generally I would say use whatever type your receivers dvd default setting calls for but coax is a more secure connection.

Your guys probably dont care much, but Monster Cable, in their "wireing guide" that came with my cables, ranks connections from source to receiver, and in the case of audio it gives: Analog(RCA) - Good Coaxial - Better Optical -Best.

After thinking about the coax-optical debate a little more, I've come to this conclusion:

I don't see how Coax could be any better than optical. There is no reason that coax would drop high frequency sounds. There are no high frequency sounds. Unless you consider a "1" a high frequency signal. I suppose that you could encounter a mirroring effect on optical with long runs, on POS cable.

If you encounter different preformance with different cable, take some isopropyl to your terminals, and make sure they are all nice and clean. That is the only way I could see a differece happening.

How do I record audio from my motorola HDTV cable box to my RCA CD Recorder? I am able to record music from the receiver tuner(analog) input not from the video 2(digital) input which has an optical connection. The video 2 connection from the cable box to receiver is optical. I do not use seperate cables for analog audio on the cable box.

When I try to record analog or digital music from this connection, the CD recorder starts but then stops shortly after and nothing has been recorded.

i,ve just sat here and have been laughing at all the people that beleave it sounds the same as i have been listening to hi-fi for years and i do like expensive hi-fi but I allso know that the most expensive does,unt mean the best quility. There is for a fact, a different sound from Coaxial Digital Connection and Digital Fiber Optical Connection most people will not be able to tell the difference but if you have the right set up you can hear that opical connection had a sharper sound, where as a coaxial connection gives you a lot richer warm sound, i have tested this theoy with at lest a dozen system's i find that it's best to balance it with your speakers, if you have rich sounding speakers then use optical and if you have sharper sound speakers that give more on the top end then use coaxial.

The truth: at last!

There are curently no speakers on the market today or ever, that could reproduse a sound equal to that of a signal transfered via optical-toslink or coaxial cable. Therefore the weakest component of a system "ie: the speakers" cannot possibly be improved down the road by your choice over the type of "digital" cable used.

People who claim to hear a differance are simpling hearing what they what to hear and therefore can think what they want to think. There infact is no way a person can put up an argument over which type of cable is better if different people hear what they want to hear.

And optical signal come from coaxial signal, so can a optical cable possibly be better?

The answer depends on many factors(such as distance, quality, etc) But these factors really are meaningless. The Answer is NO THERE ARE THE SAME. Just another way of transmitting the same signal(1's and 0's).

John A.
Morse code, once the international standard for telegraph communication, is a digital code. It is not binary, it has three letters; dot, dash, space. I think the word would be ternary.

Imagine you are viewing the Statue of Liberty, and reading its inscription. You have two friends, too far away to read it themselves, so you send it to them in Morse code. To the first, you send it along a telegraph wire. To the second, you send it by heliograph, with a large mirror reflecting the sun so he can see the flashes of light.

Assume you encoded the inscription correctly for both of them, and they both decoded it correctly. You all meet up, and discuss the inscription. One friend says he found it moving, the other said his chief feeling was that the language was a bit flowery and old-fashioned.

Question: which friend received the message by telegraph, and which by heliograph?

John A.
Sorry, I did not mean to terminate this thread. I could insult people a bit if it would help keep things going. It seemed like a nice analogy at the time. Another one would be to ask if you can tell from this post whether my computer is connected to the internet by copper telephone cable, fibre optics, or wireless LAN. I can post the correct answers if anyone is interested. Ah well.

John A.
Well, it looks as if we're all agreed, then.

I guess I killed an interesting and lively thread. It was unintentional, I promise.

I have an optical cable for my Playsation 2 and a coaxial digital cable foR my DVD player and I have found that coaxial prevides a more rich sound and is also a much more secure fitting and mucgh less easier to damage!

I have an optical cable for my Playsation 2 and a coaxial digital cable foR my DVD player and I have found that coaxial provides a more rich sound and is also a much more secure fitting and much less easier to damage!

I don't know if this was already written because there are a ton of comments. But I was speaking with a Yamaha rep and he did mention that if there are a lot of environmental disturbances, ie neon signs, power substations etc., the coaxial cable being metal are susceptible to these disturbance whereas fiber is not. Having said that, I do not know the level at which these disturbances have to exist in order to kill the transmitted signal.

Something that hasn't been thoroughly brough up yet...

What about the devices that transmit and recieve the digital signals. Could what you plug into on your player and receiver (i.e. the coaxial and optical jacks) affect the signal? There has to be some difference between the way data is read off of a disc and outputed to the jacks. Maybe it's not the cables at all (as these are just carrying 1s and 0s), but the chips etc. that transmit and receive the digital signal.

Just my 2 cents.

Wow, there is just so much misinformation about cables. I think I should start my own cable making or labeling company, Ha, Ha!! I could be rich. As an IT (information technologist with a Masters in Physics), all the signal theories I have read are intriguingly false. There are a few who have hit the proverbial hammer on the head. Mike's comical yet truthful accounts on the differences between coaxial and optical cables are dead on. In short order don't waste your money on expensive cables. I have a four thousand-dollar system that consist of a SACD player, receiver with optical input, and a thousand dollar pair of speakers. I certainly can't tell the difference, as the laws of physics would not permit, between the two cables. The coaxial cost $20 and the optical cost $6. So if you can avoid it, don't waste your money. As a final note, you couldn't hear the difference between my stereo and a live performance. Thank goodness for optical.
Check this site for more info:

Listen After reading all this the bottom line is the audio hardware industry gave u a choice rather than just tell u what to use and now no one can handle it so they just argue. So just use whatever u think sounds good u can pick up both kinds of cables for $10 or under if u have the capability try them both and decide for yourself

John A.

I agree.

Percieved differences in sound quality between coax and optical digital cables may very well be real. But it has nothing to do with the quality of the cable (assuming all the "1's and 0's" are getting there). Digital is digital, end of story. Differences in audio quality may result if the digital to analog conversion is handled differently for the different connections in your system. While most recievers/pre-amps/etc would likely use the same DAC (digital to analogue converter) for all the various digital connections on them, it is possible that there may be separate DACs for the coax and optical connections... although I am not aware of a reciever that would do this. Separate DACs = different sound quality for the different connections

I wouln't count on it. I don't have any schematics but I would bet that manufacturers have a simple circuit that converts the optical signal into the coax signal to save money.

Mr John Doe
To say that a digital signal that carries sound information holds higher quality with expensive cables is just as stupid as saying that pictures you download from the internet look better if you have expensive cables for that purpose.

Derek: By the way, electromagnetic radiation (light, for example) can travel at the speed of light. Electrons in a copper cable can not (electrons can almost reach the speed of light, or perhaps the speed of light, in a accelerator).

John A.

Yes, the optical digital signal is converted into an electrical one by a photodiode. There are the basis of optoelectronic devices including CD players. The DAC works on an electrical digital signal. So Matt's theory is most unlikely. It would be crazy for the designer to have different DACs according to the source of the signal.

There really is no quality difference between different ways of transmitting digital information.

John Doe, thanks. Please add this to my analogies of Oct 26 and Nov 3, above!

Electrical digital cable can let in electrical interference, of course. I prefer optical connection, but only for that reason.

Ray of light
Try this.... connect an optical cable to your DVD player... use the best quality cable you can afford. Hang the free end in a tank of water (an aquarium will do nicely if well placed and your fish will thank you too i'm sure). If you use a pail of warm water, you'll get a warmer sound. After the photons have had a chance to disburse evenly throughout the water, pour the water into a funnel connected to an ordinary garden hose connected to your amp... any input will do, this is digital to analog conversion and need not be precise. After the wonderful sounds that emminate from your system have come to a halt, go outside for a walk... you've obviously spent way too much time indoors.

Oh my gosh, oh my gosh!

As an engineer who implemented modulation and demodulation (aka "modem") units I can absolutely asure you that a) if optical and coax inputs go to same DAC (and I see absolutely no reason why they shouldn't; doing otherwise it asking for trouble because of many reasons) and b) there is no considerable noise and/or signal fading (i.e. your cables are relatively short) output DAC should receive exactly the same data. Which, BTW, has nothing to do with "speed of light" -- I don't even mention the fact that speed of light varies by media a lot, it's 300,000 km/hr only in vacuum, and don't mention the fact that speed of electric field is quite comparable with speed of light. Forget that we're talking about delays of about 3 nanoseconds (compare with DSP and DAC delays measured in milliseconds -- 6 orders of magnitude larger).

Everyone who doesn't believe it should make double blind test -- attach a piece of masking tape to the face of your receiver so you won't see what input it's working with and then ask someone randomly connect your CD player via coax or optical cable (i.e. O-C-C-C-O-O-C-O-C-C-O-O) making sure that you don't hear the sound of reconnection (who knows, you may distinguish insertion of RCA jack vs. optical jack). So you helper switches the inputs making a record of each connection, you don't know what input is used, and also make notes "I like it more - I like it less". For statistically reliable results make 100 tests (results will be about +-5% with 90% confidence interval) or 400 tests (+-5% with 95% confidence interval). Then see how many times you liked and disliked each connection.

If your final like/dislike coax/optical matrix is different from 25/25/25/25% +- 5%, report to CIA immediately -- they badly need devices which can intercept very low-level signals shadowed by heavy noise and perform decyphering of complex (and unknown) modulations in real time. I bet with little training you'll be able to do the trick.

Similarly, if you reliably hear the difference between gold-plated and silver-plated patch cable connectors, rush to NASA because devices that can measure 10 millionth of dB difference in signal level (worst-case scenario: 0 ohm output impedance, 10K ohm input impedance, 0.01 ohm connector resistance difference) cost more than most people make in their lifetime. BTW, from technical point of view gold-plated contact are better -- they will not oxidize.

Sorry, couldn't resist.

Thank you,


John A.
Great, Andrew.

But consider, light travels at 300,000 km/sec. Not /hr. This removes the reflection argument. The pulse reaches the detector down a 1 m cable (a bit slower, agreed) in say 3 ns. A reflection would have to do the round trip and would get their 6 ns later. At 96 kHz the next real pulse doesn't arrive until 10,000 ns later; by which time the detector has recovered and can respond again. Your slip would make reflections something serious to think about. And cause endless trouble for Physics, of course.

Sorry, I had to find the flaw in the otherwise perfect post. I still like my Morse code analogy. Great to see you describe the null hypothesis so clearly. How much the World needs a better grasp of statistics. One of its original applications concerned the efficacy of prayer. People still go on believing that, so I suppose optical/electrical is not going to go away any more easily. Faith is believing things you know aren't true.

New member
Username: Andy

Post Number: 2
Registered: 12-2003
John A ... I love your analogies too. But that's the craziest definition of faith I've ever heard. I prefer to believe in things we can't see but know are there. That's faith. The force of gravity. Soundwaves. God.

Unregistered guest
Hey guys, I'm new here and I must say this is a great forum.
I couldn't resist making this small observation: light travels at the same speed as electric current, which is the speed of an electromagnetic field. The difference is given by the medium in which the field travels. The electrons don't "run" from one end of the cable to the other, but their orientation is changed by the electromagnetic field(very simply put).

New member
Username: John_a

Post Number: 21
Registered: 12-2003
I think it was Mark Twain who said that faith was believing things you know aren't true. It is nice and provocative, and seems more like it, to me, than believing in things you can't see. That won't do, really!

Thanks.Yes, agreed. However, I always thought a direct current is simply a flow of electrons. But I think this is not really relevant to electrical signals; the current is small and changes direction at high frequency. Brief comment welcome, my physics is not all I would wish.

It would be so tempting to follow these much appreciated remarks way off topic!

New member
Username: Tim

Post Number: 12
Registered: 12-2003
My wife's Robbie Williams DVD claims to be in 5.1, but I couldn't hear anything from the surrounds last night. I'm using an optical cable - is this wrong? Should I be using coax?

New member
Username: John_a

Post Number: 23
Registered: 12-2003

Optical vs coax certainly makes no difference in this case.

Some DVDs are 2.1. If Robbie Williams is in 5.1, then it should specify the format on the box and disc: Dolby Digital, DTS or DVD-A; also on the on-screen menu. If it does not specify, then don't believe a word of it! If your system works OK on other discs, then the disc is almost certainly not what it claims.

New member
Username: Gal

Post Number: 4
Registered: 12-2003
Tim, chech the settings on the DVD player the output should NOT be set to PCM but to bitstream.

New member
Username: Tim

Post Number: 13
Registered: 12-2003
Sorry guys, I was just taking the piss out of the co-ax vs optical debate, being as it appears to be pretty much over for this month.

But thanks for your thoughts on why Robbie can't sing out of my rear end ;). I checked the ouput type - it's bitstream. The dvd menu allows to choose between 5.1 and stereo and I've picked 5.1. Can't remember what the format claims to be on the box, but the receiver auto detects Dobly Digital and the 6 speakers are illuminated on the display to confirm this. But there doesn't seem to be any sound coming out of the back.

I know the system is set up OK because I finally got round to playing Saving Private Ryan to test it. I've not seen the film yet and I only watched the first few minutes (they didn't even get onto dry land) and I can assure you that my 5.1 is working perfectly. Wow. Can't wait to watch the rest of the film. Bullets and explosions whizzing all round the room. Even the wife was impressed.

So I guess Robbie is pulling a fast one.

BTW, I'm using an optical cable and I'm very happy with it.

Seasons greetings to you all.

New member
Username: John_a

Post Number: 26
Registered: 12-2003

Taking the piss cannot be allowed here, surely there are rules about this sort of thing...? For a moment, I was hopeful you had hit on a type of digital connection that filtered out Robbie Williams. It would probably work much like the James Galway filter that people once used for classical.

Unregistered guest
Hello all! I was doing some research on coaxial vs. optical and I came across this thread. I am very new to the whole home theater experience and recently purchased a low end surround sound system (Kenwood HTB-206). The sales person at Best Buy advised that I would need either a coaxial digital cable or a digital optical fiber cable to transmit the surround sound from my DVD player to my receiver. I opted for the optical cable. Now here's my problem.

I adjusted my dvd player to transmit dolby digital and dts signals to my receiver. However, when popping in a DVD that had both DTS and Dolby Digital software on the disc, the only LED indicator that lit up on my receiver was "Prologic" not DTS or Dolby Digital. According to the manual, these LED indicators should light up when these types of signals are transmitted. I played with the input mode settings and was not successful in getting these indicators to light up.

Are the DTS or Dolby Digital signals not transmitting because I'm using an optical cable instead of a coaxial? Should it matter? Shouldn't both cables be able to transmit these signals? Might my optical cable be defective? I'm still trying to figure this out. There is a diagram in the manual that shows a coaxial cable being used to transmit DTS,Dolby Digital, & PCM components and an optical cable used for a DVD player. In the diagram showing the optical connection, it didn't mention anything about DTS or Dolby Digital components. Might this be the a special case scenario for my receiver? Any insight would be greatly appreciated. Thanks!

Anton Cuyugan

New member
Username: John_a

Post Number: 35
Registered: 12-2003

I am not familiar with your Kenwood system, but it looks to me as if you do not have correct audio settings set up, or else there is a fault.

DTS and Dolby signals should transmit with either type of digital connection. The fault could just be with the optical cable. Try a co-ax one. A single RCA-plug connection (like one half of an analogue pair) can be used safely as digital co-ax, to test.

The receiver should detect the format of the digital signal it receives and switch automatically. Digital stereo is also a possible format the receiver can detect and select.

I personally believe it is best to stick to the opinion of the industry experts (Dolby) and the laws of physics. These both say that either cable should make no difference as both signals are digital (in perfect conditions). However, as dolby mentioned, copper coaxials are more susceptible to interference when combined with greater distances. The other part is that copper cables do tend to have greater interference from nearby electrical appliances which could produce electromagnetic fields etc and therefore lead to a data loss and so a softer more natural signal. This I think is either good or bad depending on individual preferences. The downside of optical is that if it is moved around heavily or knocked around, it too can have its signal corrupted. So it is possible to say optical will produce a less warm sound due to a cleaner interference free signal.

I would personally rather go for realism in sound and stick to optical. Also, it is better protected from interference provided the cable stays in more or less the same place.

Unregistered guest

Each connection has different audio setting at yr DVD player, try to change analog to PCM or RAW. If u still face the problem try to change the digital selection from your receiver remote control, be patient u need some time to get use with new thing

hahahahahahaha, someone said to watch out for shock. yeah, so when earthquakes strike your home entertainment sound will be uneffected.

I have coax on my dvd and optical on my sat receiver. The sat receiver is definitely brighter; in a bad way.

I just tested an expensive high quality scart against a much cheaper gold plated version. There is no apparent difference whatsoever. Seems the whole thing is just a farse.
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