Are HDMI cables all the same? No. With evidence.
Discussion
A common theme:
Are HDMI cables all the same. The common PH response is:
"Yes of course, ha ha ha. Digital is ones and noughts, if you see a picture, it's the same quality."
and also:
"On longer cables the picture might drop out, but on short cables, they just work.'
A couple of years ago I bought a couple of HDMI cables. Not expensive, but not super cheap. £10 each or so for a 2m cable. It's been playing Sky HD fine with no issues since that time. Even Blu-Ray.
But, last night I used one to watch a 3D blu-ray. So, a higher bit-rate than usual. I thought my eyes were deceiving me, or there was an intentional, artistic 'grain' to the (digital) film. It looked like snow was falling on the screen. It was watchable, but you could tell it was there. Single pixels at random would have the wrong colours - especially noticeable in dark or black scenes. Maybe only a couple of pixels simultaneously, but enough to know it's there, and see it clearly.
I tried another 3D blu-ray and it did the same. Hmmm.
So, I cleaned the cable, put it back. No difference. Then, I rooted out an older cable. I stopped using it as it was a little too short, but otherwise it was a 'better' cable, costing £30 from memory.
The 'snowing effect' immediately disappeared. Just to check my eyes, I replaced the old cable and it came back again.
So, not every HDMI cable is the same. Even short ones. And even reasonably priced ones.
Are HDMI cables all the same. The common PH response is:
"Yes of course, ha ha ha. Digital is ones and noughts, if you see a picture, it's the same quality."
and also:
"On longer cables the picture might drop out, but on short cables, they just work.'
A couple of years ago I bought a couple of HDMI cables. Not expensive, but not super cheap. £10 each or so for a 2m cable. It's been playing Sky HD fine with no issues since that time. Even Blu-Ray.
But, last night I used one to watch a 3D blu-ray. So, a higher bit-rate than usual. I thought my eyes were deceiving me, or there was an intentional, artistic 'grain' to the (digital) film. It looked like snow was falling on the screen. It was watchable, but you could tell it was there. Single pixels at random would have the wrong colours - especially noticeable in dark or black scenes. Maybe only a couple of pixels simultaneously, but enough to know it's there, and see it clearly.
I tried another 3D blu-ray and it did the same. Hmmm.
So, I cleaned the cable, put it back. No difference. Then, I rooted out an older cable. I stopped using it as it was a little too short, but otherwise it was a 'better' cable, costing £30 from memory.
The 'snowing effect' immediately disappeared. Just to check my eyes, I replaced the old cable and it came back again.
So, not every HDMI cable is the same. Even short ones. And even reasonably priced ones.
I believe HDMI can run at rates up to 3.4Gbps. At this speed it isn't just '1's and '0's - it's radio frequency stuff. If the cable isn't well matched, has breaks in it or is just too long - the signal will get distorted and attenuated. This will lead to errors when the 'digital' signal is reconstructed at the other end. I've no idea what error correction protection/protocols are used but I doubt they are 100% robust.
I can well believe your results.
I can well believe your results.
op said:
"Yes of course, ha ha ha. Digital is ones and noughts, if you see a picture, it's the same quality."
But you are not seeing a complete picture, some of the data has not transferred properly, hence the static.Besides, I can't speak for everyone but when I have made comments about HDMI cables it's usually been in reply to people saying things like a certain cable has a 'warmer' picture or has better 'depth' to the sound which are (usually) complete nonsense.
Static, dropped sections of the picture, audio dropouts are all perfectly possible on damaged or otherwise substandard digital cables. Same on HDMI, cat5 or any other digital cable standard.
Edited by budgie smuggler on Friday 15th November 12:19
Edited by budgie smuggler on Friday 15th November 12:19
No they are not the same, I know the age old argument of digital either works or not, but this is not the case. you need to go deeper and look at the error correction rates and data loss etc, The better the cable (up to a point) the losses will be less so more of the information gets where it’s needed without the screen tying to fill in the blanks. I have tested many different cables and you do see a difference when back to back with different cables, I don’t agree spending £000's but definitely don’t buy cheap.
JustinP1 said:
A common theme:
Are HDMI cables all the same. The common PH response is:
"Yes of course, ha ha ha. Digital is ones and noughts, if you see a picture, it's the same quality."
and also:
"On longer cables the picture might drop out, but on short cables, they just work.'
A couple of years ago I bought a couple of HDMI cables. Not expensive, but not super cheap. £10 each or so for a 2m cable. It's been playing Sky HD fine with no issues since that time. Even Blu-Ray.
But, last night I used one to watch a 3D blu-ray. So, a higher bit-rate than usual. I thought my eyes were deceiving me, or there was an intentional, artistic 'grain' to the (digital) film. It looked like snow was falling on the screen. It was watchable, but you could tell it was there. Single pixels at random would have the wrong colours - especially noticeable in dark or black scenes. Maybe only a couple of pixels simultaneously, but enough to know it's there, and see it clearly.
I tried another 3D blu-ray and it did the same. Hmmm.
So, I cleaned the cable, put it back. No difference. Then, I rooted out an older cable. I stopped using it as it was a little too short, but otherwise it was a 'better' cable, costing £30 from memory.
The 'snowing effect' immediately disappeared. Just to check my eyes, I replaced the old cable and it came back again.
So, not every HDMI cable is the same. Even short ones. And even reasonably priced ones.
Hi Justin - I am not questioning there was a repeatable difference between the 2 cables you used but your last statement does make some big assumptions. Would the result have been the same if you had used two different examples of each cable ? How do you know the example with the 'snowing effect' was not faulty in some way etc etc etc. This is anectodal 'evidence' and must be treated as such.Are HDMI cables all the same. The common PH response is:
"Yes of course, ha ha ha. Digital is ones and noughts, if you see a picture, it's the same quality."
and also:
"On longer cables the picture might drop out, but on short cables, they just work.'
A couple of years ago I bought a couple of HDMI cables. Not expensive, but not super cheap. £10 each or so for a 2m cable. It's been playing Sky HD fine with no issues since that time. Even Blu-Ray.
But, last night I used one to watch a 3D blu-ray. So, a higher bit-rate than usual. I thought my eyes were deceiving me, or there was an intentional, artistic 'grain' to the (digital) film. It looked like snow was falling on the screen. It was watchable, but you could tell it was there. Single pixels at random would have the wrong colours - especially noticeable in dark or black scenes. Maybe only a couple of pixels simultaneously, but enough to know it's there, and see it clearly.
I tried another 3D blu-ray and it did the same. Hmmm.
So, I cleaned the cable, put it back. No difference. Then, I rooted out an older cable. I stopped using it as it was a little too short, but otherwise it was a 'better' cable, costing £30 from memory.
The 'snowing effect' immediately disappeared. Just to check my eyes, I replaced the old cable and it came back again.
So, not every HDMI cable is the same. Even short ones. And even reasonably priced ones.
I do love this topic. 
It's digital, it's 1s or 0s, it can't be wrong. Can it?
Well, that's true enough, so long as you have enough time to check and correct any errors.
So when you're using digital (1 and 0) for computer stuff it's not an issue, a computer will check and re-quest a resend of any damaged data. It will take as long as it takes to do this.
For TV and media , you don't have the luxury of being able to wait, it's real time display. So, if there are errors, and those errors take too long to be re-transmitted, your TV will not have enough data to build a prefect picture and will start to lose quality.
The higher the definition , the larger the volume of data that must arrive at the TV within a given time frame. The more data the more errors that must be re-transmitted.
A poor quality cable or a longer one will introduce more errors to the data. Each of these errors can only be fixed by re-transmitting the corrected data.
So combine the two above, a cable creating errors and increased data transmission rates , with a fixed time to repair and display, means quality can be impacted by cheaper cables.
Not that I've ever spent a fortune on any cables, but I can see where it's possible that two cables, one perfect, the other slightly longer or poorer quality could be enough for the viewer to start seeing the dropped packets in the quality of what they are watching.
It's digital, it's 1s or 0s, it can't be wrong. Can it?
Well, that's true enough, so long as you have enough time to check and correct any errors.
So when you're using digital (1 and 0) for computer stuff it's not an issue, a computer will check and re-quest a resend of any damaged data. It will take as long as it takes to do this.
For TV and media , you don't have the luxury of being able to wait, it's real time display. So, if there are errors, and those errors take too long to be re-transmitted, your TV will not have enough data to build a prefect picture and will start to lose quality.
The higher the definition , the larger the volume of data that must arrive at the TV within a given time frame. The more data the more errors that must be re-transmitted.
A poor quality cable or a longer one will introduce more errors to the data. Each of these errors can only be fixed by re-transmitting the corrected data.
So combine the two above, a cable creating errors and increased data transmission rates , with a fixed time to repair and display, means quality can be impacted by cheaper cables.
Not that I've ever spent a fortune on any cables, but I can see where it's possible that two cables, one perfect, the other slightly longer or poorer quality could be enough for the viewer to start seeing the dropped packets in the quality of what they are watching.
Crackie said:
Hi Justin - I am not questioning there was a repeatable difference between the 2 cables you used but your last statement does make some big assumptions. Would the result have been the same if you had used two different examples of each cable ? How do you know the example with the 'snowing effect' was not faulty in some way etc etc etc. This is anectodal 'evidence' and must be treated as such.
Good point.As I mentioned in the OP, the first thing I thought, as you have done was the cable itself was damaged or corroded etc. Funnily enough, as I mentioned in the OP, I do have two identical cables, bought at the same time, so presumably the same batch.
After cleaning the cable terminations, the next thing I tried was the identical cable, and got the same effect of incorrect pixels.
As I sat scratching my head, I thought of trying the more expensive cable I had, then thought 'Nah... on a 2m cable, that won't make a difference.' But it did.
But don't 3D blurays require a higher spec HDMI cables? As you say 3D bluray has higher bandwidth requirments, which is more data. Even PC cables have maximum recommended lengths at given speeds, be that twisted pair network cables or SATA cables used to connect hard disks.
Was the cheap old HDMI cable which didn't work up to the required spec for 3D bluray (somthing like HDMI 1.3/ 1.4, is it?)? If "yes" that that would be a smack in the face to all those (myself included) who preach the go for the cheapest cable to the required spec, which I thought was the general consensus when recommending HDMI cables.
Was the cheap old HDMI cable which didn't work up to the required spec for 3D bluray (somthing like HDMI 1.3/ 1.4, is it?)? If "yes" that that would be a smack in the face to all those (myself included) who preach the go for the cheapest cable to the required spec, which I thought was the general consensus when recommending HDMI cables.
Mr_Yogi said:
Was the cheap old HDMI cable which didn't work up to the required spec for 3D bluray (somthing like HDMI 1.3/ 1.4, is it?)? If "yes" that that would be a smack in the face to all those (myself included) who preach the go for the cheapest cable to the required spec, which I thought was the general consensus when recommending HDMI cables.
The very fact that there are different specs of HDMI cable puts the lie to Justin's 'all the same' suggestion - but I don't think anyone has ever suggested that cables of different specs are all the same. However, clearly the cable in question isn't performing to spec even if it should be up to the job, so it's broken/missold/mislabelled/whatever.I've seen the snow on a cheap 1.5M cable. It was fine at 720p but it snowed on 1080p.
I think the point is: if you don't notice any issues than you don't need a more expensive cable. For most people a Poundland job will probably be fine. If not, a £10 one will almost certainly cure any problems. There's simply no point spending more.
I think the point is: if you don't notice any issues than you don't need a more expensive cable. For most people a Poundland job will probably be fine. If not, a £10 one will almost certainly cure any problems. There's simply no point spending more.
If you are spending around £1200 on a TV what harm is there in spending £70-£80 on high quality HDMI cables that will deliver the right picture quality and signal all of the time, not just with 720i or non HD.
Try two different cables and the quality is there to see...cheap vs engineered. As I have always said, like tyres on a car or a wrist watch!
Try two different cables and the quality is there to see...cheap vs engineered. As I have always said, like tyres on a car or a wrist watch!
I think the point is that with all digital cables, the cable is either good enough or it isn't. Once it is good enough to transmit the data so that the receiving equipment can get the data stream without error then there can be no further improvement due to it being gold plated, made of some wonder material or having it dipped in the tears of babies or whatever bulls
t gets put on the packets of expensive cables. A £10 cable which is up to standard will provide exactly the same quality output as one costing £100. There are other differences such as durability, or appearance which might make people justifiably spend more, but they shouldn't expect any audio/visual improvement over a cheaper one which is up to standard.
t gets put on the packets of expensive cables. A £10 cable which is up to standard will provide exactly the same quality output as one costing £100. There are other differences such as durability, or appearance which might make people justifiably spend more, but they shouldn't expect any audio/visual improvement over a cheaper one which is up to standard.
belleair302 said:
If you are spending around £1200 on a TV what harm is there in spending £70-£80 on high quality HDMI cables that will deliver the right picture quality and signal all of the time, not just with 720i or non HD.
Try two different cables and the quality is there to see...cheap vs engineered. As I have always said, like tyres on a car or a wrist watch!
There is no harm in spending £70-£80 however using the best materials available certainly doesn't guarantee any higher performance, the performance depends upon the spec of the cable. If it was an old £70 v1.2 cable then a £5 v1.4 is likely to perform better, and the recent v2.0 is better still. The link link below might be helpful. To use your wrist watch example, is a £50k Patek Philippe better than a Sekonda or Casio ? Clearly the materials used and build quality in the Patek are far superior but that doesn't mean it will be any better at telling the time..........Try two different cables and the quality is there to see...cheap vs engineered. As I have always said, like tyres on a car or a wrist watch!
http://en.wikipedia.org/wiki/HDMI
Edited by Crackie on Saturday 16th November 07:59
belleair302 said:
If you are spending around £1200 on a TV what harm is there in spending £70-£80 on high quality HDMI cables that will deliver the right picture quality and signal all of the time, not just with 720i or non HD.
Try two different cables and the quality is there to see...cheap vs engineered. As I have always said, like tyres on a car or a wrist watch!
Not at all, a cheap £5 cable built to the 1.4 spec (or whatever the current requirement is) will be just as good as your £70-80 cable for watching 3D 1080p blurays.Try two different cables and the quality is there to see...cheap vs engineered. As I have always said, like tyres on a car or a wrist watch!
Spending £70 on a 1m cable 5-6 years ago, when the only spec was 1.1 (before 3D) is no guarantee that it would work with a 3D bluray now. This is because it wasn't qualified to that level of performance, even if it was was 'well engineered'. Where as any HDMI 1.4 cable that isn't broken should work fine.
Also remember to use a cable appropriate to the source.
You will get away with cheapies on the skybox as its HD output is S***, upscaling DVDs etc also dont need anything fancy
Blu ray 3D etc may need something better.
Also you are much more likely to spot errors on 47 inch screen than you will on the bedroom 19 incher
Try not to bend them sharply either, if the TV is wall mounted then get a cable with 90 degree plug on it rather than letting the TV crush the plug against the wall.
Dont let the big retailers con you into a lead either, you are paying a lot for a bit of fancy blister packaging, the internet is your friend, you can make do for a couple of days with the cheapie till the good one arrives.
You will get away with cheapies on the skybox as its HD output is S***, upscaling DVDs etc also dont need anything fancy
Blu ray 3D etc may need something better.
Also you are much more likely to spot errors on 47 inch screen than you will on the bedroom 19 incher
Try not to bend them sharply either, if the TV is wall mounted then get a cable with 90 degree plug on it rather than letting the TV crush the plug against the wall.
Dont let the big retailers con you into a lead either, you are paying a lot for a bit of fancy blister packaging, the internet is your friend, you can make do for a couple of days with the cheapie till the good one arrives.
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