HDMI cable and quality

[admin_exported]

Hi,

Can someone explain in very simple terms why one hdmi cable will give better sound and picture than another? (If they do). By digital I assume the signal is 1 and 0. It gets sent by the sender and recieved by the TV. The TV will interpret the 1 and 0 and show picture and play sound. Either the 1's and 0's are wrong or right and it is down to the sender to send the message and the cable to transfer it. Either it transfer the data or it doesn't. Or are we saying some cables sometimes turn a 1 into a 0?

Thanks,

Chris

 

[VoodooDoctor]

Try doing a search of the forums, there are hundreds of posts on this topic.

 

[Andrew Everard]

Chris,

It's late. You don't want to be starting this... It'll only turn out messy...

 

[professorhat]

 

[Andrew Everard]

 

[Messiah]

christhedon:
Hi,

Can someone explain in very simple terms why one hdmi cable will give better sound and picture than another? (If they do). By digital I assume the signal is 1 and 0. It gets sent by the sender and recieved by the TV. The TV will interpret the 1 and 0 and show picture and play sound. Either the 1's and 0's are wrong or right and it is down to the sender to send the message and the cable to transfer it. Either it transfer the data or it doesn't. Or are we saying some cables sometimes turn a 1 into a 0?

Thanks,

Chris

THIS should help!!

 

[margetti]

Aaaaaarrrrrrrrrrggggggggggghhhhhhhhhhhhhhhhhhhhhhh!!!!

 

[kena]

"There are only 10 types of people in the world: Those who understand binary, and those who don't"

The information can get mangled cause interference...

 

[Anonymous]

Ok my bad. I see the other threads. Doesn't seem to be any solid conclusion. Some people notice the different some don't. Interesting one expert video the guy said either you get a picture or you don't. If you get a picture then it won't be different using different cables. But a bad cable means that you might not get a picture, I can believe that because I've experienced it. There still seems to be no simple 'logical' explanation as to why you get a better picture. So if I find that I'll try reply with a layman explanation of it.

 

[professorhat]

I think you'll have more luck finding the Holy Grail, but I wish you well in your quest

 

[Anonymous]

If the cable supplies the signal, there is categorically no difference in the subjective areas of the signal.

Cables ALWAYS cause attenuation of the signal, in cables carrying analogue information this often results in certain frequencies becoming more or less apparent, this obviously changes the final result. By using a high-end cable you minimise that attentuation and get the best picture and sound possible.

When the system is digital, it is designed that any attenuation that occurs is below the threshold to cause errors... although, using really long HDMI cables will cause the attenuation to increase beyond the threshold, resulting in signal failure.

Because the signal is digital, the error correction will correct the signal in most cases. Even when errors occur which do result in a 1 becoming a 0, this will not manifest itself in 'less treble' or 'fuzzy edges'. Digital signals are encoded, and simply don't work like that... any interference will cause random error, in most cases this will not affect the signal in the slightest, in worst cases it will stop it completely.

A great analogy, would be to say, that MP3's sound exactly the same no matter what brand of Hard Drive you are listening to them from... its the original encoding, the decoding stage, the amplifier and the speakers which make a difference.

In conclusion.... if the HDMI cable supports the specification... HDMI 1.3 or whatever, and if it works... it produces the best picture quality possible using your HD Source and TV/Receiver/Speakers.

Spend your extra money on those bits, not the cable.

 

[Simon Lucas]

Blimey, Zing - one post and it's a monster.
I trust you've started as you mean to go on.

 

[Gerrardasnails]

Simon Lucas:Blimey, Zing - one post and it's a monster.
I trust you've started as you mean to go on.

Please, Simon, LOCK DOWN! These newcomers who open up with, "can someone please explain why 0,1,0,1 can be improved...", are on here to start boring arguments.

 

[Andrew Everard]

Perhaps the 'it either works or it doesn't' brigade could explain sparklies, then. Surely the picture should either be there or not, not there but with sparkly interference?

 

[margetti]

That's done it... just sit back and watch those sparklies fly...

EDIT: oh, already flying in the OTHER thread...ÿ

 

[Anonymous]

I want to get to the bottom of this... so don't think of this as me trying to argue against anyone, but just trying to figure out the truth behind the matter.

Ok, so there are digital signal errors which can occur, and can be visible, but as I mentioned previously they are random in their impact. One particular HDMI cable will not consistently cause certain colours to be reproduced incorrectly, or the audio to lack treble or anything like that.

To understand how these errors occur you have to look at the codec used to transfer audio and video. For example, I think the video uses H.264/AVC on Blu-ray.

As I understand codec relies on separating the image into blocks of pixels and using a discrete cosine transform to encode the block.. I'm not going into that now, but this is why when you have poor reception on you digital satellite the picture breaks up in blocks, and sometimes individual blocks turn a funny colour or appear to freeze.

This same effect happens when the signal passing down the HDMI cable becomes heavily attenuated, it will manifest in the same way, but if it isn't happening, then your picture should be as perfect as its ever going to be. In theory it should only begin to happen at all when the signal is right on the error threshold, and so only in cables which are too long, not to specification, or faulty.

 

[Anonymous]

Wow, thats the best laymans terms i've read so far concerning HDMI and cabling.
It certainly makes it clearer for the brand/price argument.

Can we make that explanation sticky?

 

[shado]

In the good ole days - one would set aside 10% on their Hifi purchase for quality leads and everyone was happy. I have a £80 Panasonic lead, a £15 lead from Amazon and a midrange Chord lead from Richer Sounds. I am happy with all purchases as it easier to identify which one supplies what item.

 

[Clare Newsome]

It's been linked to in other threads, but for the sake of those new to this one, here's QED's explanation of how HDMI cables work.

 

[Anonymous]

Clare Newsome:It's been linked to in other threads, but for the sake of those new to this one, here's QED's explanation of how HDMI cables work.

The only trouble with a brand explaining things is that some will still not believe what they are saying, as there will be some kind of bias to shift their own products. It would be bad business for a company such as QED to say all cables perform the same.

Until there is a specific unbiased body that gives a scientific explanation as to why hdmi cables perform differently or not people will carry on debating this matter.

 

[Andrew Everard]

Ginder:people will carry on debating this matter.

Clearly...

 

[Alec]

"When tomorrow's products come, you will have the satisfaction of knowing that all your Signature cables exceed the maximum specification that even those products could hope to achieve."

How come?

Did'nt understand most that blurb (it did help a bit), so it wont make a difference in my choices in future, nor did it address, clearly and directly enough, the opposite arguments you always find on sites such as this.*

why make a dedicates ps3 hdmi?

why are so many manufacturers sites shy about their prices?

* Well, i might have. im still mulling that over. superficially, of course, they just said "hdmi cables - theyre complicated", while sucking their teeth.

PS ive no axe to grind (how does one grind an axe?!). Guess who's hdmi i use...

 

[Andrew Everard]

al7478:(how does one grind an axe?!)

Like this

 

[Messiah]

Perhaps we'll all have wireless HDMI soon and put the issue to bed!!

 

[Alec]

Andrew Everard:

al7478:(how does one grind an axe?!)

Like this

T'riffic! Cheers! Ya live 'n' learn!