Upgrading digital cables a waste of money?

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heath1s

Standard Member
I ask, becuase in the world of computers, networking and the like, you can send a signal without dropping of 1's or 0's over long distances and don't have to spend a fortune for the wire to do it. Examples: Ethernet, phone wire between BT box and router, the firewire link between my camcorder and laptop etc etc, usb 2 link between pc and ipod. If even 1 bit of data got lost, then the files being sent would be corrupt.

I can understand in the analogue world becuase of mains hum, cross talk, and wanting to cleam signals to your speakers then you need to upgrade. But why with digital interconnects like HDMI, coaxial digital surround out etc. Seems like a case of "Because you can".

The thing that will make the difference in quality is surely as things go analogue i.e. D/A converters in the receiving equipment, quality of the power amps and not what happens whilst the signals are still digital. Or in the case of a digital TV the ability of a TV to decode and move the info to the screen without dropping some of the info and getting the encoded info displayed correctly, i.e colour representation, fast movement etc.

Simon.
 

Kendalbeefcake

Active Member
Hi,

I come from a similair technical background and when I started to get into hifi more I was initally of the opinion that digital is best and couldn't see the point in spending moneny on fancy digital cables and bought a load of cheap fibre cables. Cut a long story short, moving from cheap fibre to relatively expensive one definatly made a difference for me even from sources such as digital tv which are relatively lossy and in theory shouln't benefit much from the extra bandwidth, but they did. Even weirder, despite being susceptable to interfearnce, Coax sounds even better (which is the reverse of the network world, where coax is dreadful stuff). I think that it probably makes more of a difference the better the kit; good cables can make good kit sound kit.

I think that the accepted opinion is that cabling makes no sense, especially to those used to the more cut and dried world of networking..

Can't bring myself to spend more than £100 on an indiviudal cable tho..
 

hamster

Novice Member
Optical suffers badly from timing jitter. That's the commonest reason why optical sounds poor.

However, unless you are using doorbell wire, there will be no difference in coax cable provided the bit error rate is roughly the same and only something like 1:1000000 bits are wrong.

Anyone who claims that the cable magically "improves treble" or the "tautness of bass" (etc) should be questioned as the bit losses are random, and a cable cannot magically improve the bits that are for treble for example.
 

heath1s

Standard Member
I've just found a couple of articles which have convinced me (for HDMI anyway) a cheap cable probably isn't a good idea. Especially if you have plans to use 1080p. Although for me cable length isn't going to be a problem - av boxes sit under the telly. What it did bring home is that the bandwidth in HDMI are very high, and the standard is flawed because of using twisted pairs. It does also means that should I get around to getting a projector then component video is the sensible option.

http://www.bluejeanscable.com/articles/hdmi-cables.htm
http://www.bluejeanscable.com/articles/whats-the-matter-with-hdmi.htm

On a side note - I came across the articles in the sticky about using CAT5 as speaker cable - something I'd have never considered before.
 
J

jackal

Guest
I am sure that you will find that the end result of this thread will be heavily polarised opinions at best - (heavy arguements most likely).

I use high end digital cables and I am convinced that there is a big difference to freebie cables. However that is based on my own observations nothing more. No amount of blind testing, quasi scientific arguements for and against will convince me otherwise - for one simple reason I am an individual with my own particular set of senses (sight hearing etc) it does not follow that anyone else would perceive any difference. Indeed I am willing to admit that there is a styrong psycholoigical apsect to my perception of good quality cables.

I also believe that this works the other way round and that those who do not believe that digital cables make any difference will be swayed one way or the other. My point is that this arguement has been made so many times on the forum, often with both sides trying to make it a black and white issue - no consensus is ever reached - it is not black and white for me.
 

JohnWH

Active Member
Audio is a funny thing, experience will only ever be subjective and will vary from occasion to occasion as such the arguments will never end. For video on the other hand it is much easier to get to the truth of the situation, if you can see a difference then take a photograph and post it for the whole world to see. Open to abuse yes, but most people on these forums are pretty honest and so we have yet to be presented with evidence showing the sort of differences that are impossible yet occasionally claimed.

Regards,
John.
 

JohnWH

Active Member
I've just found a couple of articles which have convinced me (for HDMI anyway) a cheap cable probably isn't a good idea. Especially if you have plans to use 1080p. Although for me cable length isn't going to be a problem - av boxes sit under the telly. What it did bring home is that the bandwidth in HDMI are very high, and the standard is flawed because of using twisted pairs. It does also means that should I get around to getting a projector then component video is the sensible option.

http://www.bluejeanscable.com/articles/hdmi-cables.htm
http://www.bluejeanscable.com/articles/whats-the-matter-with-hdmi.htm

On a side note - I came across the articles in the sticky about using CAT5 as speaker cable - something I'd have never considered before.
I think you need to read the HDMI artical again, it clearly and accuratley describes the failure mode for HDMI cables, it says nothing that implies use of more expensive cables over shorter runs will give you a "better" picture, in fact the exact opposite is true. Its also worth pointing out that Blue Jeans HDMI cables are not particularily expensive and do an excellent job on longer runs.

John.
 

baldrick

Novice Member
Anyone who claims that the cable magically "improves treble" or the "tautness of bass" (etc) should be questioned as the bit losses are random, and a cable cannot magically improve the bits that are for treble for example.
This has always been my take on digital inter-connects.

All that is travelling down a digital optical/coax connector are sets of 16 1s and 0s. These 1s and 0s are almost like co-ordinates and when you plot them out you get a likeness of the original analogue audio signal.

CDs audio is sampled at 44KHz so every second of music is represented by 45056 co-ordinates so for every second of music there are 520896 '1's and '0's travelling along your digital inter-connect.

If you lose any of those '1's and '0's between source and destination you will not get a 100% perfect sound and similarly if you add any '1's and '0's you won't hear what was originally recorded.

For a digital inter-connect to be able to change a particular facet of the music (bass etc...) the connection would have to decode the the data stream, pass it through a graphic equaliser and re-encode it into a 44KHz, 16 bit data stream.

No matter how much you pay for a length of coax cable it is not doing what I just detailed so if you can here distinct tonal differences between 2 digital cables it's in your mind.

You may here distorted sound with blips and pops if too many '1's and '0's are lost but other than that a good quality interconnect will ensure all the data gets from source to destination and nothing else!!!
 

hamster

Novice Member
No amount of blind testing, quasi scientific arguements for and against will convince me otherwise
It's interesting that you regard Electronic Engineering as a quasi-science...

If the world didn't repeatably follow the formulae then none of this stuff would be designable.
I have never seen a ouija board, dreamcatcher, graven image or juju in our development labs.
:devil:

Maybe as we are now making ICs in CMOS 090 we have also manages to miniaturise the pixies...?
 

Brogan

Novice Member
I use high end digital cables and I am convinced that there is a big difference to freebie cables. However that is based on my own observations nothing more. No amount of blind testing....will convince me otherwise
Why do you categorically state that "no amount of blind testing" will convince you otherwise?
Why not?
If you're that confident that you are able to see/hear the difference with various cables then surely a blind test should be exactly the way to go as that way you are guaranteed to get the best cable possible, based on your perception. It may even be that the cheaper cable performs better and you could save yourself a lot of money.

I also believe that this works the other way round and that those who do not believe that digital cables make any difference will be swayed one way or the other.
I am of the camp that unless a cable is faulty or not fit for purpose, a cheap freebie bundled cable will be no worse than an expensive piece of AV candy.
This is not an entrenched position based on science or logic but as a result of testing.
I have performed testing on mains, analog audio, digital audio and digital video cables and have yet to see or hear a difference.

The only time I did see a difference was with analog video (e.g. scart and S-Video) and a cheap 15m HDMI cable which had severe signal loss causing sparklies and colour bleeding.
 

Pecker

Distinguished Member
I've long thought that there are 3 levels of cable.

The cheapie ones you sometimes get supplied for free are often (though not always) poor, in that they're poorly screened, poorly put together, and which poorly fit.

You then get decent cables, which are generally not expensive, but might cost, say, £20 for a SCART. They fit, they're properly screened, etc.

Then there's the third type - the 99.99999999% OFC jobs, etc. £5,000 a meter, etc. Complete waste of money.

I've found this to be the same whether using analogue or digital cables.

Jakal is, of course, correct. If he wants to spend more money and it sounds better to him, who's to tell him what to spend his money on. I'm sure I've wasted far more brass on dafter things.

Steve W
 

KingKrell

Novice Member
No matter how much you pay for a length of coax cable it is not doing what I just detailed so if you can here distinct tonal differences between 2 digital cables it's in your mind./QUOTE]

I have to say that when it comes to USB, PCs, Networking, etc I have found little difference in digital cables, assuming there is good shielding. With TV digital cables, usually mid-range ones work well and hyper expensive ones have very small gains. I have also found little differences in optical cables, but they are there, although very subtle. However, when using digital coaxial cables to transmit PCM data from transport to DAC, I have heard distinct tonal differences in cables. It's not simply bass/treble, but more to do with clarity and presentation.

e.g. Stereovox XV2 - mellow, relaxed. Chord Signature- forward, exciting, full bodied sound. Belden Canaire - tight, detailed, but a little flat/2D. Bellwire - flat, 'grainy' with the odd pop when the light switch goes on, but it works.

I feel I have to say this: ITS NOT IN MY MIND :boring:

I do believe there is more at work here.
 

KingKrell

Novice Member
The only time I did see a difference was with analog video (e.g. scart and S-Video) and a cheap 15m HDMI cable which had severe signal loss causing sparklies and colour bleeding.
Those should be sweeping changes. With most digital cables, it's a much more subtle change.
 

heath1s

Standard Member
Mmmn thanks for the replies - Seems the are definetely 2 schools of thought on this.

For me - especially with audio only links I can't see (should that be hear) how the sound can be better. The only thing that could make a difference is something affecting the timing of the 0's and 1's arriving so that as the level value changes from sample to sample it would incurr some kind of pitch shifting effect. But I don't think that's possible as I believe it's all clock synched - not just send randomly down the wire hoping that the amp is listening. It should be very easy to handle such a low bandwidth transmission, so I guess that it's a case of having to go and have a listen.

PS I originally asked this question becuase I'm finally getting round to upgrading to a proper separates hifi. Even the wife wants one - she has loads of vinyl so we'll be spending a bit on the analogue cables, but I just can't see the point on the CD - amp link (£10 max).
 
R

recruit

Guest
heath1s - this subject is talked about all the time on the forums and generally there are 2 camps the believers and the non believers and the best advice is generally to demo or borrow the cables from a dealers and explain you're situation to them and hopefully they will be Obliging and let you hear for you're self and then you can decide.
 

loz

Well-known Member
heath1s - this subject is talked about all the time on the forums and generally there are 2 camps the believers and the non believers
I didn't know AV was a belief system

Belief is usually defined as a conviction of the truth of a proposition without its verification; therefore a belief is a subjective mental interpretation derived from perceptions, contemplation(reasoning), or communication.
I mean, no other part of the signal chain is based on belief is it?
We understand the science of how pits get burned in a CD or a DVD.
We understand the science of what those pits represent.
We understand the science of how pixels get displayed on a screen.

So why is it that so many seem reluctant to accept the science of cables transfering the information, and instead would turn it into something that is subject instead to ones beliefs? :confused:

If people perceive that cables can make a difference to digital signals, then surely they can offer proof by means of presenting evidence or scientific reasoning.

I can't see why anyone allows belief to hold sway in something so scientific as av. This isn't religion.... or perhaps it is...
 

deaf cat

Active Member
Heath1s - If your in a shop and buying separates, I would definatley see if you can borrow say a £5-£10 digital cable and a £200 one (either both coax or both optical - maybe both types....) and just see if you can hear the difference......down to you then:thumbsup:

If you like the difference it could cost you more money:rolleyes: if you hear no difference you know the money you have spent is well spent and you can't get better out of your separates:smashin: when using different digi cables.


A question for the more electrical minded members, I know the loss of 1's and 0's is pretty close to 0, but if you have a pulse (1) square wave going down a cable, could the cable not affect the shape of that pulse (square wave) and maybe make it a bit more rounded so the actual timing of the top of the wave is out a bit from the original......
Sorry you may have guessed my electronics is naff, do not know if anyone else understands what I am getting at, just trying to find an explanation as to why I may hear differences in different coax cables:eek:

:)
 

JohnWH

Active Member
A question for the more electrical minded members, I know the loss of 1's and 0's is pretty close to 0, but if you have a pulse (1) square wave going down a cable, could the cable not affect the shape of that pulse (square wave) and maybe make it a bit more rounded so the actual timing of the top of the wave is out a bit from the original......

Sorry you may have guessed my electronics is naff, do not know if anyone else understands what I am getting at, just trying to find an explanation as to why I may hear differences in different coax cables:eek:

:)
I assume you are refering to jitter in the recovered clock of the digital signal?

Certainly in the case of digital audio jitter can result in an audible difference, this is a known problem. What is questionable is the claim that there are audible differences resulting from jitter in the recovered clock from data delivered using two peices of 75Ohm coax, over a distance of 1 or 2m, where both peices of cable are rated to 500-1000MHz with good low loss and group delay charactistics and the signal is actually band limited to 6MHz (as is the case with spdif). I personally doubt that there would be a measurable difference, and unsurprisingly there has never been a test conducted that shows such a difference exists.

In terms of HDMI cables (as these where raised originally) the interfaces are designed to be tolerant of jitter in the recovered clock, and further to this jitter is actually irrelevent to the "appearence" of the data due to the manner in which devices recieving the data work. No doubt I will be accused of being elitist again for saying it, but, this is fact not opinion :D

Cheers,
John.
 

andykn

Novice Member
The big difference between HDMI and what us IT nerds are used to is twofold:

1/ HDMI has no error correction so the destination has no way of knowing if what it gets is any good or not
2/ HDMI has no feedback; on the internet your computer will tell a website to send stuff again if the 0s and 1s don't add up in the error correction system.

Like the OP said, if an IT bit gets corrupted its trouble. If an HDMI bit gets corrupted you may see one pixel wrong on the TV, but it may not be very wrong. I can't think of any way a poor HDMI cable could produce a 'softer' picture or some of the other reported differences.
 

Brogan

Novice Member
I can't think of any way a poor HDMI cable could produce a 'softer' picture or some of the other reported differences.
Yet apparently they can, along with "punchier" and "more vibrant colour" and other such picture quality improvements...
I for one would really like to see clear examples of these reported improvements in picture quality as I would be the first one to 'upgrade' my cables but unfortunately no-one yet has been able to demonstrate it.
 

baldrick

Novice Member
Mmmn thanks for the replies - Seems the are definetely 2 schools of thought on this.

For me - especially with audio only links I can't see (should that be hear) how the sound can be better. The only thing that could make a difference is something affecting the timing of the 0's and 1's arriving so that as the level value changes from sample to sample it would incurr some kind of pitch shifting effect. But I don't think that's possible as I believe it's all clock synched - not just send randomly down the wire hoping that the amp is listening. It should be very easy to handle such a low bandwidth transmission, so I guess that it's a case of having to go and have a listen.

PS I originally asked this question becuase I'm finally getting round to upgrading to a proper separates hifi. Even the wife wants one - she has loads of vinyl so we'll be spending a bit on the analogue cables, but I just can't see the point on the CD - amp link (£10 max).
I actually asked a senior lecturer from Cambridge who specialises in digital data transfer SP-DIF etc... and it was his view that the cables provided in the box are more than suitable for digital interconnect work.

Obviously because this is ONLY the reasoned, justified OPINION of a lecturer at one of the worlds most pretigious universities who's performed an awful lot of research on this subject, the 'believers' on here dismissed his input as 'just another opinion'....
 

KingKrell

Novice Member
and it was his view that the cables provided in the box are more than suitable for digital interconnect work.
Yes, they are, but they can sound different. I've never had a shielded digital cable fail or corrupt the data. Even a 'wet string' will work, but they may sound different.
 

Brogan

Novice Member
Yes, they are, but they can sound different. I've never had a shielded digital cable fail or corrupt the data. Even a 'wet string' will work, but they may sound different.
If the signal is not corrupted in any way and there is no signal loss down the length of the cable then it's not possible for the resulting sound to be different.
 

Pecker

Distinguished Member
Do a test on yourself.

Do not let a dealer set it up.

Try to set it up at home. Try to get a source with (for example) 2 coax oututs and an amp with 2 coax inputs.

Get a friend to switch between the two.

Ensure your listening is 'blind'.

If you can't hear a difference, it's a waste of money.

If you can, you need to ask if it's a big enough difference to warrant the outlay.

If anyone tries to puruade you not to carry out this test, or let a dealer do it for you, you should be very sceptical indeed.

Steve W
 
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