HDMI leads...

[Alec]

Not sure whre the hypocrisy is. The comp would be run anyway, and plenty will enter who are'nt in immediate need of that length and brand of hdmi - or any - just as free gifts sometimes help give would-be subscribers that extra little push.

 

[Anonymous]

dvdaudio:i just wonder how many anti hdmi people who have mouthed on the forum have done the hdmi comp on the home page and wishing to win the chord hdmi cable, myself included you never know it might be better eh..
right guys own up whos entered the competition.

That'll be me then. I can't tell the difference between my £5 CYK cable and my £18 QED cable, but maybe the £85 Chord will convince me!

Despite an inauspicious start this particular HDMI thread has been the most amusing so far with some very funny postings. Keep it up!

 

[Anonymous]

Andrew Everard:

Yes, but I can't understand why the subject is so sensitive and emotive. If you think they work, or experience benefits when you try, buy; if you don't, don't.

Simple as...

Think of any unproven phenomenon that you don't believe in. Could be astrology, quack medical treatments, tarot cards etc. For each of the above there are people making vast amounts of money out of credulous believers. Do you simply feel indifferent about this, or do you consider it immoral for people to profit from selling a product that fails to live up to its claims? Would a response of "well, if you don't believe it yourself then you don't have to buy it" stop you from caring about the victims who were being conned?

Obviously I'm not suggesting cable manufacturers are necessarily as bad as the above, but hopefully you get the point.

Personally I am on the fence when it comes to the cable debate, as I haven't auditioned enough of them under the right conditions to make an informed judgement. However, I can certainly understand why a sceptic would feel it important to challenge what they perceive to be an almighty ripoff.

 

[Andrew Everard]

No one's questioning the right to debate the subject ad nauseam. It was the original poster's suggestions of corruption on our part that got me so annoyed.

 

[Anonymous]

Andrew Everard:No one's questioning the right to debate the subject ad nauseam.

Your use of the term ad auseam suggests a certain frustration that the debate continues. Sometimes the best way to end a debate is to win over the opposition. Perhaps if you invited the most prominent and measured sceptics to come and experience the differences that WHF report on, and to observe the test method in action, the debate could be put to bed. I'm sure that any reasonable sceptic would post honestly here on what they observed.

In the mean time the facility to have the debate here without censure is very much appreciated, and is a credit to the WHF team.

 

[Andrew Everard]

smithdom:Your use of the term ad auseam suggests a certain frustration that the debate continues.

No, it's not meant to suggest that at all.

 

[idc]

Andy510:

Think of any unproven phenomenon that you don't believe in. Could be astrology, quack medical treatments, tarot cards etc. For each of the above there are people making vast amounts of money out of credulous believers.

Like wine or perfume, where some can hardly taste or smell a difference, but to others it is their joy in life and they love the differences. There are no scientific measurements involved, the differences are discerned by tasters and sniffers which result in one bottle of wine costing £3.99 and another £399.

Andy510:[Personally I am on the fence when it comes to the cable debate, as I haven't auditioned enough of them under the right conditions to make an informed judgement. However, I can certainly understand why a sceptic would feel it important to challenge what they perceive to be an almighty ripoff.

If it really was an almighty rip off then the cable industry would be a minute one with a following that would not have any place in the mainstream. But cables are an integral part of hifi and a large part of the hifi community do report worthwhile changes when different cables are used.

 

[visionary]

aliEnRIK:
So as I understand it ~ the best approach to all this is just close your eyes and ignore everything

That would certainly be a "blind" trial

can we at least talk about "double masked, randomized cross-over trials"

 

[True Blue]

Have QED and HD Cable platinum HDMI cables and I must say that with both (compared to the freebie leads) the 0's are rounder and the 1's are much sharper

 

[Anonymous]

idc:But cables are an integral part of hifi and a large part of the hifi community do report worthwhile changes when different cables are used.

And for analog cables this is plausible. However, I have yet to read a technical explanation of why two digital cables, both performing to the same HDMI specification, would vary in their perceptible performance. I have been directed to several articles and YouTube videos, some of which are very interesting, but none of them even attempt to explain how one HDMI cable performing to specification will give better results than another HDMI cable performing to the same specification.

Even QED's page eulagising there own products differentiates between cables in their HDMI range on the basis of future proofing and providing head room against challenging signals. It does not claim the kind of difference that we read about in cable reviews. I would expect a less than perfect digital signal to manifest itself in unsubtle ways such as pixellation, picture freeze or sound breaks. The subtle differences described in reviews are counter intuitive.

I am not an expert and I don't have the means to conduct proper tests myself, which is why I ask questions here in the hope that those better informed than myself can provide good technical explanations for the results that they see and hear. I'm still hoping.

 

[Andrew Everard]

Anyone else noticed that the original poster has never returned...?

 

[laserman16]

You would think they would of come back on to thank everyone for their input.Seems almost as though they came on to stir up a hornets nest.

 

[Andrew Everard]

Surely not...

 

[laserman16]

Maybe I'm being a bit to harsh. I really must have more faith in human nature.

 

[laserman16]

In fact the OP has not signed back on since their original post.

 

[Andrew Everard]

Indeed. Strange behaviour...

 

[idc]

smithdom: I am not an expert and I don't have the means to conduct proper tests myself, which is why I ask questions here in the hope that those better informed than myself can provide good technical explanations for the results that they see and hear. I'm still hoping.

Same here, Smithdom. I think the main issue and reason why such cable debates (especially for digital cables) spark up and at times go mad is that something that should not make a difference, does apparently make a difference. By that I mean enough people report a difference to make debates worthwhile, as opposed to one person who totally flies against the norm. Maybe the explanation is not technical but psycological and cables are the homeopathic medicine of the hifi world. Anyway, scientists can be wrong as according to aeronautical engineering, the bee should not be able to fly.

 

[Anonymous]

I've been a telecoms engineer for over 20 odd years and I can honestly say that this should not be an issue. If one cable is better than another than this is a measurable property (physically measurable). It will also depend on the circuitry of the receiving device as some are more able to cope with degraded digital signals than others.

Surely WHF could conduct such a test as this really isn't rocket science...

 

[idc]

Hi Fandangio. In what way do digital signals degrade? I have continually read that digital signals are either there as 1 and 0 or not there. If they do degrade is this not the answer as to why digital cables are reported to sound different in different systems?

 

[Anonymous]

Without getting too techie different cables have properties that degrade signals in different ways. A square wave (1's and 0's) is made up of a frequency and all it's odd harmonics. These harmonics degrade differently according to the properties of the cable. Notably the highest frequency harmonics degrade the most quickly resulting in rounded off edges of the square wave.

The reason this isn't a problem is that the receiving circuitry can easily discriminate as to what should be a 1 or 0. The problem only occurs when the source signal is so badly degraded that this cannot be done accurately. Typically over short cable lengths this is never a problem but issues may occur over longer runs.

There is a fairly basic guide here: https://wwws.ee.ucl.ac.uk/postgraduate/masters/notes/ITN/Izzat_ITN2008_lecture3_digital.ppt

Slide 7 gives a basic idea of the process

 

[idc]

Thanks for not being too techie! So even though a signal can degrade, it is unlikely to on your usual HDMI length and in any case any degredation is corrected anyway. But could it not be the case that that is not actually happening in some cables, so that explains the reported differences?

 

[Anonymous]

Fandangio:The reason this isn't a problem is that the receiving circuitry can easily discriminate as to what should be a 1 or 0. The problem only occurs when the source signal is so badly degraded that this cannot be done accurately. Typically over short cable lengths this is never a problem but issues may occur over longer runs.

In your opinion, Fandangio,
[*]Is there instrumentation that can accurately measure errors introduced by an HDMI cable?[*]If the signal into an HDMI cable could be compared to the signal emerging at the other end, and was found to be identical, would you expect to be able to discern any difference in performance between two HDMI cables that faithfully transmit the signal?[*]If the signal emerging was not identical, in other words if errors were being introduced by the cable, how would you expect this to manifest itself in the video and audio performance?

 

[aliEnRIK]

Fandangio:
I've been a telecoms engineer for over 20 odd years and I can honestly say that this should not be an issue. If one cable is better than another than this is a measurable property (physically measurable). It will also depend on the circuitry of the receiving device as some are more able to cope with degraded digital signals than others.

Surely WHF could conduct such a test as this really isn't rocket science...

Absolutely true. The problem ive seen thus far is that the tests ive seen have all been either by eye or in perfect conditions

What I mean by that is that one website MEASURABLY saw errors in the signal but couldnt see them onscreen (They were expecting to see 'snow' or complete screen failure etc). So that means the picture HAD degraded but the guy just couldnt tell (Maybe someone else could, who can say?)

Then you have the guys with the 'super equipment' sending a signal down the line and seeing when they get failures. As youve clearly pointed out in your statement though thats not in REAL use. In REAL use you have the effects of jitter and differing voltages from the equipment that created the signal in the first place. EMI and CROSSOVER effecting the signal within the cable itself and how sensetive the receiving equipment is

Ergo ~ under perfect conditions a 2 meter cable probably does perform perfectly. In REAL world conditions connected to bog standard equipment and surrounded with EMI it might not fair so well

 

[Anonymous]

To be honest I think it's amazing what rubbish components and circuitry you can get away with to achieve a required outcome.

If the source device and receiver are working properly I can't see a cable less than a couple of metres in length having any significant difference. As you've correctly said the siting of any cable is more significant than the cable itself (ie moving away from mains leads and avoiding long parallel runs).

 

[Anonymous]

Taking the argument to its logical conclusion, I would have thought that there should actually be no difference in Blu Ray players either. They are reading a digital signal and delivering it to a digital output. It is not until analog conversion takes place that the opportunity would arrive for performance differences.

In the computer world, we would laugh at someone who suggested buying an expensive disk drive because it really got out all the details of the accounts. The files are either read or not, and there are suitable parity and encoding checks to enable simple error correction and detection.

Given that there does seem to be a difference, then this implies that different readers are delivering different digital outputs from the same input file which is interesting. I wonder if it's a bandwidth thing and that more expensive readers are able to keep up with the stream of information more accurately and that the format of the files is such that the picture and audio is acceptable with incomplete data but improves the more that is delivered....