Digital = a set of 000000000001111111111111110000000000000 -how can a cable send 000111 better than another?

[admin_exported]

I am so confused,  why should a very dear HDMI cable transmit a digital signal better than a cheap one and also for the life of me I cant understand how a cable ie HDMI can affect sound quality, is that not the job of speaker cables, speakers, amp

 

 

abbey

 

[Cofnchtr]

Hi,

How can an Aston Martin cost 100 times more than a VW - it's just metal, rubber and leather...

How can one TV show pictures better than the other - they're all showing broadcast quality pictures...

Cheers,

Cofnchtr.

 

[The_Lhc]

Cofnchtr:Hi,How can an Aston Martin cost 100 times more than a VW - it's just metal, rubber and leather...How can one TV show pictures better than the other - they're all showing broadcast quality pictures...Cheers,Cofnchtr.

Spurious arguments there I'm afraid, in the latter case you have an analogue element (the final picture) which is always affected by the quality of the components (which is why speaker cable DOES make a difference) and in the former case, well, you're comparing two active devices (cars, with different engines etc) with two passive devices. You could use the car argument if you were comparing DACs for example, because they actively process the signal. I can't actually think of anything in the car world that would beÿequivalent to HDMI cables, roads maybe.

You could have just said the better cable reduces the need for error correction in the receiving device and it would have (rightly or wrongly) sounded entirely plausible but that boat has flown, so to speak...

 

[Cofnchtr]

Hi,

My analogy was to show that although in both cases you are starting with the same components, they have been put together in a certain way and therefore produce different end results.

Cheers,

Cofnchtr.

 

[The_Lhc]

Cofnchtr:Hi,My analogy was to show that although in both cases you are starting with the same components, they have been put together in a certain way and therefore produce different end results.Cheers,Cofnchtr.

Respectfully, material, perhaps, components, no, not really, apart from minor electrical items perhaps.ÿ

 

[cram]

ABBEY:

I am so confused, why should a very dear HDMI cable transmit a digital signal better than a cheap one and also for the life of me I cant understand how a cable ie HDMI can affect sound quality, is that not the job of speaker cables, speakers, amp??

gbmitie

They don't send the digital messages better than one another per se. What they do is protect that message from interference helping to ensure that the message sent is the message received.

 

[Messiah]

I am not a great believer in varying qualities of HDMI leads. As long as it is built correctly to the right specs it should be fine. I base this view on a couple of things.

1. The theory that (as has been mentioned) the better leads protect the data better. How long can it honestly take to design / produce a lead that protects the data enough that we would not notice a difference?? I don't think it would take long and I believe that current leads do this job already.Maybe I am wrong

2. Look at companies such as Meridian who now use a RJ45 connector and CAT5 cable - "featuring balanced drive and RJ45 connectors for simplicity and elegance of installation via CAT-5 cabling". Now surely a company like Meridian do not put much stock in data loss digitally if it uses standard CAT5 cable??? LINK

 

[Anonymous]

Then why do we come across countless 'faulty' HDMI cables that give a blank screen in our work as a tv service/repair centre? (In response to your first point)

 

[cram]

Can't comment the Meridian device that you've linked to as have no real knowledge of it. Have plenty experience of dealing with Cat5 from years of installing networks

One of the reasons that signal integrity is so important for HDMI is the lack of error correction. So once data is lost/corrupted it has gone for good.

The reality is that most HDMI cables probably do a good enough job (otherwise you wouldn't get a picture or the picture would suffer from excessive noise). Improvements in shielding/construction certainly do help protect the data being transmitted (and as cables gets longer this becomes more important) but as you pay ever increasing amounts you are chasing an ever diminishing return. The difference between say a £200 cable and a £20 cable is at very best likely to be small (specially when weighed up against all the other things that effect the overall picture/sound quality). But if that small difference is important to you then by all means spend the money.

I'm not convinced about the argument put forward earlier about taking some weeks/months to appreciate the difference as we're not talking about something that needs running in here. However, by all means try and get some cables on approval and make your own mind up on which parts of your system should receive the most attention.

 

[pioneer7]

 

[cram]

alsina:

Then why do we come across countless 'faulty' HDMI cables that give a blank screen in our work as a tv service/repair centre? (In response to your first point)

You're not really comparing apples with apples though. Here you are talking about a lead that is physically damaged as opposed to why do some leads maintain a better digital stream.

 

[Anonymous]

It's a lot of tosh!ÿ

Digital is 0 and 1. Having a better component quality wont change the information being transferred from source to the TV. If the signal does have errors you will find that you have MAJOR issues with the picture like big glitches and blackouts or a completey blank screen. The idea that a better built digital cable can improve a picture has got to be all in the mind. Think about when a CD misreads data because of dirt or a scratch. When that happens the sound is TOTALLY distorted. It's not subtle at all..ÿ

ÿThe chances are a better built quality might last longer because it uses better matterials, but as to making a picture better... thats just cant be true..

ÿ

 

[Anonymous]

cram:alsina:

Then why do we come across countless 'faulty' HDMI cables that give a blank screen in our work as a tv service/repair centre? (In response to your first point)

You're not really comparing apples with apples though. Here you are talking about a lead that is physically damaged as opposed to why do some leads maintain a better digital stream.

Not at all. I'm talking about cables that will quite happily carry 576i/p but when asked to carry 1080p from a Blu-ray to a tv, the result is a blank screen. Swap the cable with a decent one with the same Blu-ray/tv combination and hey presto, 1080p works a treat. And I'm talking short cables here, typically 1.5 or 3m.

Am I missing something?

 

[cram]

threesixty: Digital is 0 and 1. Having a better component quality wont change the information being transferred from source to the TV. If the signal does have errors you will find that you have MAJOR issues with the picture like big glitches and blackouts or a completey blank screen.

If you have a lot of interference then yes you will get big glitches and blackouts. You need to keep in mind that there is a lot of data being transferred along a cable. This data isn't one single message that gets through or doesn't. It's lots and lots of small packets of data. A small number of damaged packets will not necessarily leap out at you as a major issue. You also have to factor in signal attentuation. Its strange that everyone seems to accept that long (15m +) HDMI cables will result in poor sound/audio. The degradation doesn't suddently start at the 15m point. Likewise bad packets are accepted fact of life on computer networks where digital data is being transmitted over twisted copper pairs.

Going back to your CD analogy your incorrect there. CDs can withstand a certain amount of scratches and smudges without it being jump out noticeable. Firstly CDs include a degree of error correction. Secondly if they get too many errors they will interpolate samples to get a resonable value. A best guess if you will. Its only at the extreme end that you get clicks and pops.

As I said before I'm not totally sold on the benefits of so called (and priced) premium cables. Personally I'm happy with my cheaper cable.. Having said that to dismiss a cables construction as having no effect on the data it is carrying is, well, a lot of tosh!

 

[cram]

alsina:Not at all. I'm talking about cables that will quite happily carry 576i/p but when asked to carry 1080p from a Blu-ray to a tv, the result is a blank screen. Swap the cable with a decent one with the same Blu-ray/tv combination and hey presto, 1080p works a treat. And I'm talking short cables here, typically 1.5 or 3m.

Am I missing something?

Not at all - I misunderstood you. Would however, be very surprised if you were seeing lots of these.

 

[Messiah]

alsina:cram:alsina:

Then why do we come across countless 'faulty' HDMI cables that give a blank screen in our work as a tv service/repair centre? (In response to your first point)

You're not really comparing apples with apples though. Here you are talking about a lead that is physically damaged as opposed to why do some leads maintain a better digital stream.

Not at all. I'm talking about cables that will quite happily carry 576i/p but when asked to carry 1080p from a Blu-ray to a tv, the result is a blank screen. Swap the cable with a decent one with the same Blu-ray/tv combination and hey presto, 1080p works a treat. And I'm talking short cables here, typically 1.5 or 3m.

Am I missing something?

Well if it carried standard def but not high def as you have given in your example, it would not be up to 1.3a standard would it?

All I am saying is that a cable that meets the 1.3a spec should also have been engineered in this modern day and age in such a way that in everyday use there are no effects on its performance.

 

[Anonymous]

The problem seems to be that a lot of the cheap HDMI cables available on the high street do not meet the 1.3 spec, or if they do they are only standard speed (cat 1) cables rather than high speed (cat 2).