Coaxial or Optical?

[sivart22]

Coaxial or Optical?
Can't seem to get a straight answer from anyone.

[Chromy]

And you probably won't

There are many differing oppinions regarding optical or coaxial digital audio connections.

IMHO as long as the digital signal gets from one component to the other with no errors (e.g. the string of digital data "1010101010" comming out of the DVD player looks like "1010101010" to the decoder and not "10_0101__0") then it doesn't matter.

It can't matter, and that is the miracle of digital data transmission. Almost any quality short cable that you can buy will create the necisarry connection needed for this digital transmission. All that a digital cable has to do is shuttle 1's and 0's around at a certain rate.

Think of it like the internet... Does the quality of phone line going from your wall to computer (assuming that it can handle the bandwidth needs of the connection) make the fonts that you are reading now somehow different? No, becuase as long as the data ("1010101010") from the web server makes it to your computer unhindered, you will see the same thing that others see (well, not exactly... someone using a different digital decoder, i.e. browser, might see something slightly different... that is where the interpretation of the digital data and making it into something that humans can use comes in)

My $.02... although others will come in and tell you that the gold plated $300 1 meter co-ax telephone wire that they are using makes the forum look much "warmer", "well defined", and brings out "subtle details".

Chromy

[Tyler Durden]

Aaaahhhh Nooooooooo - not this old can of worms again. People tend to get very, very heated about this one but just to say that the argument that digital data is a load of 1's and 0's and therefore nothing else matters is a load of old tosh. And Chromy, no offence but your post above is a load of old rubbish quite honestly (see, I'm getting heated already ) Comparing the internet and fonts and so on is ludicrous beyond belief and bears no relation whatsoever to the task at hand. I will not go too far deeply into this one (I have done so before and am certain there are some of my papers on this forum somewhere to peruse) suffice to say that if Chromy and 1138 and so on are correct then ALL CD players, DVD Players, Digital Radios, Digital TVs and so on WOULD BE EXACTLY THE SAME - which is clearly not the case at all. Yes a digital data stream is a 1 or a 0 but there is something called corruption of data - hence the fact that ALL CD PLAYERS HAVE ERROR CORRECTION - hardly necessary if Chromy et al are to be believed and this is one of the many basis in terms of differing sound quality with varying mediums used in the construction of cables.
(What that sentence meant I have no idea but I'm sure you get the gist)

I personally always connect my gear with coax cables, where appropriate obviously - I use a Chord Prodac silver cable. I find this vastly superior to optical and I at least can hear a big enough difference betwen this and other coax and optical cables so that I can make an informed choice. I have asked many, many times for people on this board to do comparisons but nobody has of yet - at least nobody's replied yet. If you can, ask your dealer to lend you some cables - try:

Chord coax cable
Van den Hul The First Ultimate
Ixos Optical cable

If you audition these side by side and cannot hear any difference whatsoever then I will be very, very surprised - so surprised that I frankly wouldn't believe you - so there.

Go ahead and try it - I genuinely think you will be very surprised by the results.

T

[This message has been edited by Tyler Durden (edited 08-28-2001).]

[THXHEYNOW]

I had originaly used the coaxal but have been using optical for a few years now. Aside from it being a lot more money i havent noticed a difference. Though when i used the coaxial i didnt have as good a system then. Accutaly arent they called rca's or component wires? i thought coaxials were the regular ones you get television off of and stuff.

[Wirehed]

Most high end audio shops will loan you a couple cables for a few days.

I use Tranparent http://www.transparentcable.com for all my cable neads.

But it all depends on what you are comfortable spending. I can't afford what I want or I would get the highest quality cables made. I have friends that have them and beleive me it makes a huge difference. As it is I have middle of the road.

[Chromy]

Tyler, nice to see you are still browsing these pages.

Here we go

Comparing the internet and fonts and so on is ludicrous beyond belief and bears no relation whatsoever to the task at hand.

I think that it is a fairly accurate analogy... data is sent digitally from one source (web server/DVD player) transmitted as digital data over a physical medium (in both cases, optical or conductive wire) and then to a device that then takes the digital data and converts it to a format that we as humans can perceive in a meaningfull way. Just in the way that a browser can affect slightly the way a web page is visually renderd, so can a DAC affect the way that digital audio is rendered.

ALL CD players, DVD Players, Digital Radios, Digital TVs and so on WOULD BE EXACTLY THE SAME - which is clearly not the case at all.

The A/V difference in these components has to do with the rendering of an analog signal from digital input. My argument is that most cables (yes, even the cheap spaghetti ones that come with some components) deliver the digital signal through the wire without any dropped or misinterpereted bits on the other end.

Yes a digital data stream is a 1 or a 0 but there is something called corruption of data - hence the fact that ALL CD PLAYERS HAVE ERROR CORRECTION

Error correction is used to compensate for corruption of data.. but what is the cause of corruption?
From the Jim Taylor FAQ...

That is, data is stored on DVDs using powerful error correction techniques that can recover from scratches as big as 6 millimeters with no loss of data.

There are numerous other passages about how error correction works with scratched or dirty discs. Which brings me to my primary point about CD/DVD error correction... In that it happens previous to the buffer... data is then read out of the buffer (error correction data is now stripped out) and then video and audio data streams are then extracted from the buffer. Digital audio is now sent out either a coax or optical port to the decoder... free of any encoded error correction.

I have asked many, many times for people on this board to do comparisons but nobody has of yet - at least nobody's replied yet.

Ok, I'll bite... Recently a couple of us moderators and admins compared generic spaghetti cable, to cheap optical cable, to an $80 Monster digital co-ax, to some $300 monstrosity that Taxi has (help me out here with the brand)... the results? In A-B comparisons, no-one could reliably pick the difference between the 7 year old freebie that came in the package with some piece of gear to the $300 30 pound 1m thing that Taxi has. You might say that my system is not revealing enough? Well, that's of course a point of debate, but I can hear differences between components reliably, so I would argue that it's revealing enough to hear a "huge difference" if it was there.

This combined with the fact that there is no sound technical explanation to explain why a 'more better' digital signal makes any difference at all, as long as data is recognizable at the other end of the pipe. 10101010 goes in and 10101010 comes out at 1% lower voltage still looks like 10101010 to the DD decoder.

Chromy

[This message has been edited by Chromy (edited 08-28-2001).]

[Taxi]

My $300 (US) cable was a Tice Audio DC-1A cable.

(Looks like from the web page that they can be had for considerably less than 300 bucks now. But then again, what do I care? I got mine for free. )

[Wirehed]

Are you talking about video here or sound or both?

What in the heck are you running? I can tell a huge difference in cables even on my PS2!

I needed a new coax for my LD player just a few months ago. It's my backup unit and I didn't want to spend a lot on it or I would just bought another Transparent Video coax (sometimes I put a cartoon LD in or something to run a pre-show)

I took home a bunch of different cables from my dealer and every single one of them was drastically different.

I think it's easier to see the difference in video (especially on a large screen rear projection) cables than audio. At least it seems that way to me. I always bring friends over when I'm doing tests and it seems to me that most people are more keen to see differenced than hearing them. myself, I hear huge differences in cables too.

BTW in the lower cost cables, I liked the $30 Optical cable over the less than $100 cables.

[Chromy]

Before we get too off track here... by the topic that was started "Coaxial or Optical" I assumed that the discussion would be focused on digital interconnects (the ones that go from your transport to your DAC or your DVD player's digital audio output to your DD/DTS decoder)

Analog signals are a whole other ballpark... these are the ones that you are talking about. Because of the way that analog works, any decrease/increase of resistance at any frequency results in colored output on the ohter end. This includes video cables, (analog) audio cables, and speaker cables.

Granted that many video/audio cables are of "coaxial" design usually these are refered to a component/composite/or audio cables, where coaxial usually refers to digital cables (although it is usually prefaced by 'digital')

Chromy

[1138]

*sigh*

When you're talking digital, cable makes no difference in terms of quality. Despite what Tyler says, Chromy's anaolgy is very appropriate. In the same veinb, no one argues about the quality of your IDE cable connection if your hard drive to your computer and yet people still insist that coax or optical is better than the other. And yes, if you're using digital connections and the chips inside are able to handle the full bandwidth of an audio CD, then all CD players should sound the same when hooked up digitally to the same equipment. Otherwise, what's the point of using digital connections?

What's happening here is a fundamental lack of understanding about what digital is and how it works. We didn't come up with digital because it's of higher fidelity. We came up with it becuase it provides and easy way of getting exact copies/transmissions and because it is highly independent of medium. "Highly independent of medium" means it doesn't matter what the "quality" of your cable is as long as it works. Digital is set up to either work or not work. There is no in between. Thanks to the wonders of voltage and frequency cutoffs, a digital cable is either going to be able to transmit it's two basic signals or it's not. If it's not working, you'll hear very obvous dropouts and what not. That's the other aspect of digital: it doesn't get slightly messed up like analog. When a digital sginal is messed up, it gets messed up slightly and greatly. It won't discriminate towards one.

Now, if you have any questions or would like me (or Chromy if he wants) to explain or address some issue about this, please do. I'd be happy to spend time explaining stuff to someone.

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1138 - DVD File Forum Greeter/Moderator
Oh, him? He's harmless. Part of the free speech movement at Berkeley in the sixties. I think he did a little too much LDS.

[tomdkat]

Ill put in my 1 cent...

The only thing I can think of to attribute to cabling differences is the quality of the media in the cable that is transmitting the bitstream. Provided the media in the various cables is the same, I would speculate that a $5 cable would produce the same results as a $50 cable.

However, if the $5 cable used inferior media (prone to interference or something) then I can see there being differences in quality of the cable simply because the bitstream could be inadvertently modified due to the poor cable media.

Peace.....

[1138]

True. A cheap cable might be more prone to breaking or interference that makes it stop working. But I doubt that the physical difference between a $20 cable and a $200 cable is much or worth it.

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1138 - DVD File Forum Greeter/Moderator
Oh, him? He's harmless. Part of the free speech movement at Berkeley in the sixties. I think he did a little too much LDS.

[tomdkat]

Originally posted by 1138:
True. A cheap cable might be more prone to breaking or interference that makes it stop working. But I doubt that the physical difference between a $20 cable and a $200 cable is much or worth it.

Would it be worth 1 cent?

Peace....

[Dave Bean]

Hey, look what just opened up in front of me....Pandora's Box.

Dave Bean

[Wirehed]

Well, i'm in no way capable to argue the science behind this.

One of my best friends is an engineer and we argue about this all the time. (and I should point out, he listens to MP3s and thinks they are "just fine") The problem is I can't argue with his "bits is bits" other thanto say listen to this, it sounds better, explain that.

I have run a number of coax cables from my LD and DVD player. They all produce a different sound. My $375 Transparent coax is a HUGE improvement over any other cable I tested including a $30 Monster Optical. I'm happy with my purchase. If you guys were in the area I would be more than happy to demonstrate this for you. I would love to hear you argue this in person.

___

1138, Regarding your comments about all CD players sounding the same, I assume you mean as a digital transport they would all sound the same? So if we run a Theta CD player and a $99 Teak Costco specail into the same DAC using the same coax you think it's going to sound exactly the same?

[1138]

If the CD players both handled the same bit rate and bandwidth (i.e., neither down sampled to a lower kHz or a from 24 to 20 bits, etc.), sure. The DAC is doing all the work. The players and cables are justing telling it "10010101001010101010101..." and so on.

If you're really going to believe in "digital variance", why not also worry about the quality of the laser pickup, the quality of the circuit paths in the machine, the quality of the actual disc media, the quality of the air in the room, the temperature of everything involved, amount of stray alpha particles, etc.? If we're going to believe that the quality of the digtal cable matters, then I can think up of at least dozens (if not more) of other things to worry about in terms of quality that could "affect" it in the same way. But I don't because I'm confident in digital equipment to act digital.

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1138 - DVD File Forum Greeter/Moderator
Oh, him? He's harmless. Part of the free speech movement at Berkeley in the sixties. I think he did a little too much LDS.

[Chromy]

Alpha particles

Seamonkey- I think that you are still confused... there would be no reason to have multiple digital coax cables running from your DVD player or LD player... we are talking about one single ended cable that goes from your digital output on your DVD player to the DD/DTS input on your decoder or receiver.

As far as the transport issue goes? As long as any transports used in a comparison pick the bits off of the disc, and prepare them for transport across the digital cable to a DAC they will sound IDENTICAL.

The transfer of digital data from one object to another is flawless... The music/movie industry isn't up in arms because every time someone makes a digital copy of a DVD/CD the quality degrades! It is exceedingly simple to make a bit for bit copy of a cd on a computer. The duplicate is exactly identical to the original... and a computer chasis is a mess as far as RF interference and poor cable quality goes... and yet it it bit accurate.

Chromy

[Wirehed]

I'm not confused. There is only one coax from my dvd player to my receiver. I tested different cables and they all performed differently.


It's hard to argue this online since I can't show you what I'm talking about.

I'm going to have to test the CD player question sometime. I don't have an outboard DAC so I have no way to do it myself, but I'm sure I can talk the folks at my audio dealer into doing this.
_____
and I use a tachyon field generator to block stray alpha particles.

[1138]

Originally posted by Seamonkey:
and I use a tachyon field generator to block stray alpha particles.

I use tinfoil. Would you like a hat?

And back on topic, to help sivart22 decide:

I've even used a plain old non digital RCA cable to hook up a player to my receiver before (the red half of a stereo cable). Seemed to work fine for me. I certainly couldn't tell the difference in the pretty unofficial test. But you'd think that something so poorly designed for a digital connection would cause very noticeable differences, right?

Which reminds me. I was helping a friend buy a HT setup (speakers, receiver, player, etc.) last week for our mutal friend (who was also with us) for his wedding gift (a true testament to our geekiness). Towards the end, the sales dude talks to us about cables. Now, it's been said before and I concur: cables are one of the largest cash cows and mark up items in the HT industry. So naturally, this dude tries to convince us to buy the Monster optical cable over the generic one, a difference of like $30 ($50 comaperd to $20). In trying to persuade us (even though I and my non married friend were pretty adamant against), he tells us repeatedly about the Monster cable being less prone to electrical interference. On an optical cable. Which uses light. Which doesn't involve electricity. Go figure.

Now I'm also reminded of another little amusment: when in Seattle with the other admins and mods, in a hi-fi store, we saw gold plated optical cables. Gold plated. Which is good for conduction. On an optical cable which doesn't use electricity. Gold's also good at not rusting. For a plastic optical cable. Go figure.

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1138 - DVD File Forum Greeter/Moderator
Oh, him? He's harmless. Part of the free speech movement at Berkeley in the sixties. I think he did a little too much LDS.

[THXHEYNOW]

Is this why my cd's or DTS cd's skip the first second of there track and start a beat later? or is that a whole nother issue.

[Wirehed]

I have a tin foil hat thanks. Gotta protect myself from the mind control rays.

Well, I would still say that the actuall point of contact on an optical cable is pretty important.

Is the Monster optical cable better than the generic one? I don't know I haven't tested that myself. I'm not a big fan of Monster though, I think it's over hyped and over charged for.

I was using a Monster optical cable on my laser disc player for a while. I had to save up to be able to afford the better coax. Let me tell you, there was a HUGE difference when it was replaced.

[Wirehed]

THXHEYNOW, that's a whole nother issue. That's the "tag" telling your decoder that it's a DTS encoded recording.

I think this had something to do with DTS coming out late with their specifications so manufactures added it in later.. ummm... err.. something like that..

[SeanL]

This is a pretty interesting discussion ya'll have going here, although you guys lost me at "alpha particles"



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Sean

I was thinking of the immortal words of Socrates, when he said, "I drank what?"

[1138]

Originally posted by Seamonkey:
Well, I would still say that the actuall point of contact on an optical cable is pretty important.

Bt there's no metal involved with optical contacts. So why gold?

[sivart22]

Hi EVERYBODY!

Hey its me, the opener of this can of worms!

Well, I asked the Best Buy people ( 2 of them) and they said that optical is better.They also said this is true if you are not going long distances because optical can loose it over long distance. I do understand that this is all digital and 1s and 0s and getting them to where they need to go is pretty simple. I seems that optical since it is not prone to electrical interfearance would be a more solid connection for pushing 1s and 0s.

So I picked up a cheap Acoustic Reasearch optical, hooked both up to my cheap setup and switched between it and an el-cheapo Coax. I have to say that really there was not much difference and I could barely tell.

Overall I think that the optical sounds a tad bit "smoother" or "less digital"

But I do think that cables are a cash cow for HT retailers, they are always trying to get you to buy the most expensive cables.

Those of you with $300 cables,,, I do believe that it does sound better to you,

a $300 placebo effect!

[Chromy]

a $300 placebo effect!

Yep...


I'm still currious to hear from the cable people on my CD/DVD copying comments above... How is it possible to make a bit accurate copy of a CD in the computer case environment... you have the signal getting read off of one disc, going to the buffer, going across the cables to the IDE interface, going across the bus, getting processed, shoved back across the bus into the IDE adapter, and then back out across those same gray ribbon cables and out to the CD-R drive... all with no mistakes...

These ribbon cables obviously have no sheilding, round trip, you've probably gone about 2 ft... inside the case... with all of the RF interference being created by the processors,fans, and powersupply... and yet when it arrives at the MB, or even the cd burner, it is bit accurate... with the way digital works, as long as it is bit accurate there is no possible way that it sounds any different.

As long as a digital coax cable can maintain the accuracy of the bits traveling across it it will make no difference.

Chromy

[Tyler Durden]

Big, big sigh

I have no idea why some of you are so against the idea that a cable transmitting digital data can affect the perceived sound quality. Suffice to say that it is clear nobody will be swayed one way or the other but I must point out that the arguments put forth by Chromy and 1138 are spurious to say the least - here we go again guys! I say again - to compare and contrast an internet connection is ludicrous beyond belief. There are many, many, many people far better qualified than I think anyone on this board (including me) who have done scientific studies that have proved beyond reasonable doubt that cables can and indeed do make a difference in perceived sound quality when playing back digital sources. Do you honestly believe this to be some massive conspiracy theory to get us to part with our hard earned cash - I think it unlikely. I would quite like to invite some of you when you are in the UK to come and take part in some of the blind listening tests that we conduct as part of our research and review process - just to prove a point!

Before I go I should like to point out some important nuggets about digital data and cables:

A 75 ohm cable is the prescribed value for S/PDIF interfacing. Remember that in an RF transmission path source, cable and termination impedance must be identical; if one of them is off, reflections will travel up and down the cable, which deteriorates signal integrity. I would like to point out that many CD-transport digital outputs and DAC digital inputs are not true 75 ohm, at least not over the entire frequency range (40kHz-40MHz), which is necessary for transmission of the complex S/PDIF signal.
So in nearly all practical cases we are stuck with some degree of reflection. 75ohm cables are designed for low-loss. Low-loss means that it takes a long time before the reflections have damped out. High-loss means that reflections are short-lived — at the cost of some signal loss, of course — but the S/PDIF system permits a signal attenuation of 6-7dB. This goes some way to show that the medium by which a cable is constructed can indeed have a direct affect on the quality of signal and so cause fluctuations and differences in perceived sound quality.

That's it, for now

T

[Taxi]

If there have been scientific studies that prove this, show us one. Link to it.

You say the comparisons that Chromy has made are "spurious," yet you never say why. WHY WHY WHY? He's certainly given you reasons why his comparisons are valid. (Digital domain, signal carried across a wire, etc.) What makes the Home Theater digital signal path so much more special than the digital data being saved to my hard drive?

We did a lot of A/B switching at our Seattle get together, and I can tell you that at no time did anybody say "Hey, it sounds better when we're using player X (with my expensive Tice cable) instead of player Y (with cheapo wire)". And we're talking about a group of several audiophiles! One of us would have mentioned a perceived difference. I'm not saying we thought the expensive stuff sounded worse, but that it sounded identical. (As it should, being played through the same decoder/speaker wire/speakers.)

And here's something for the newer folks around here:

http://www.dvdfile.com/interactive/f...ML/000004.html http://www.dvdfile.com/community/for...ML/000027.html http://www.dvdfile.com/interactive/f...ML/000116.html http://www.dvdfile.com/interactive/f...ML/000282.html http://www.dvdfile.com/interactive/f...ML/000342.html http://www.dvdfile.com/interactive/f...ML/000399.html http://www.dvdfile.com/inte