HDMI cables, expensive vs cheap

[lee789]

Ok, a bit of a report this.... sorry! But I've been frustrated by the lack of science behind Stuff magazine's preaching on the topic of HDMI cables. They recently did offer up some welcome science, hence this report.




Summary



Stuff magazine's view on HDMI leads is to buy expensive leads for your home entertainment system (see p251, January 2009). I disagree with this. After testing various cables 2 metres in length on a standard living room set-up, I noted that the differential in image quality offered by the cables is either unnoticable or non-existant. I conclude from this symptom that the limited electromagnetic conditions and the minimal length required for HDMI cabling in our homes causes the majority of us no reason to purchase expensive HDMI cabling.



Testing




To prove to myself that I wasn't just adopting a cynical attitude towards professional gadgeteers telling us that cabling is far more important that we might think for digital signals, I took the opportunity of playing two Blu-ray versions of The Dark Night on two separate PS3's plugged into two HDMI inputs on the same HDTV (Samsung LE40A756). I was able to do this by chance really; I took my PS3 to my brother's house for christmas where we had duplicates of the key components.



There was one difference in the twin set-up: the HDMI cable. My brother got talked into paying £70 for the cable, the salesman iterating time and again that its silly to spend £800 on a TV but not get a high quality cable (but he could not explain the science as to why the expensive cable should perform better in a living room scenario). I actually brought two cables with me: a £4.99 cable purchased online and a £9.99 cable bought at gamestation. All 3 cables were 2 metres.



We played the movies simultaneously with exactly the same picture settings for both HDMI channels on the TV and with both PS3s set-up identically.




After testing the £9.99 cable against the £70 cable, I repeated for the £4.99 cable against the £70 cable.



Test results were observational in form. My two brothers and our girlfriends were witness to this geek-ridden event. We compared the cables by switching HDMI channels on the TV with an obsessive desire to spot any differences. Comparisons and up-close inspections were made of freeze-framed images, slow motion playback, playback in film and TV native frame-rates, picture extremities (image reproduction in low/high contrast and in low/high brightness etc.) and we also fiddled with the TV and PS3 picture processing software.



Results



Nothing. Everytime we flicked from cheap to expensive cabling the picture was no different (both were fantastic, I couldn't see how the picture could be better). Not one of us in the room could see a single, not a single difference. For what its worth, the sound was no different either (but of course this would need to be tested on a proper surround sound set-up).



Conclusion



Signal degradation (digital data-packet loss) in a HDMI cable of two metres or less does not occur to the extent necessary to warrant high-end materials and their associated cost. Perhaps for a 10 metre a cable the extra shielding and build quality is necessary. But for your standard home set-up? No, definitely not. It's also worth mentioning that the TV used for this test would be considered awesome just 12 months ago, and Stuff has been proclaiming the virtues of expensive HDMI cables for longer than this - hence to say that a higher-end TV would spot any differences would be erroneous. Furthermore, with TV's coming down in price, expensive HDMI cables are becoming a larger percentage of cash spent on a decent set-up, so my view is this: please please don't tell people to spend more money than they need to for results they will not get. I felt my brother got conned by a salesman who probably didn't even mean to con him!




Stuff, remember that science is beautiful but the magnitude of forces and the context in which they're exerting has to be rigourously verified: think Coriolis effect and the water-swirl myth.



I'm spent!

 

[logic_187]

with digital connections it doesnt make sense to use expensive cable as it doesnt make any difference to pic/sound quality, its all 1's and 0's. Unless its over longer runs then you will need to invest more in a well built cable even then you dont need to spend ludacris ammount of money.

Its funny the number of people who fall prey to buying uneccessary expensive hdmi cables.

 

[Oily]

But you've also get to take into consideration build quality.I'm not one for spending £70 on a cable but paying a few quid on a cable,i wouldn't expect it to last to long.More importantly,if your going to bury the cable in some AV install you might want it to last.

 

[digidude]

ive got a 10M long HDMI cable in my setup, i paid about 14 quid for it

the floor staff in places like comets make more comission on cables, thats why they puss them

i install freesat, and the number of jobs i go to where they have paid 80 quid for a receiver, then 90 quid for a cable, as they were told they need one (theres one in the box) and that they would have a pi$$ poor picture without the good one

ive said for ages its no difference, but people want to justify to themselfs that their outlay was worth it

 

[carlos]

i just bought a couple off e bay for £ 1.75 . they do the job !

 

[Thommo]

But you've also get to take into consideration build quality

sorry but once my cheapo is in place it does not move so i doubt theres going to be anymore wear and tear over a more expensive one.

 

[rawsy]

ixos are one of these so called quality lead manufacturer. and while i worked for the sony centre i opened up one of their scart leads and the soldering was piss poor and very messy im not sure how the pins werent shorting. i know we are on about hdmi but its still the same sort of firm making them. and agree that there is no need for these expensive leads in a normal setup and think there may be a possability for a need over a much greater distance.

 

[nara]

But you've also get to take into consideration build quality.

I only use cheap HDMI leads and they're built like battleships. The sockets they go into have more chance of failing.

 

[steve7713]

I only use cheap HDMI leads and they're built like battleships. The sockets they go into have more chance of failing.

Got to agree, there must be more strain of the socket than the cable. The cable cheap or not has a plastic case to help support, sockets rely on the connections on the board and the weight of the cable will stress it.

Unless you can or want to tweak your system and environment to perfection you would be unlucky spot the differences.

My mate spent £60 for a cable (sales men have a lot to answer for) he tried my £1.99 cable and bought 1.

 

[die5el]

HDMI cables are digital and therefore only send ones and zeros. Unfortunately everyone is wrong. HDMI in common with all copper (and indeed wireless) signals are NOT digital, they actually carry an analogue waveform on which is superimposed a digital signal. In simple terms the voltages on the cables are constantly changing (hence analogue) if it's above a certain value then the receiving equipment interprets it as a 1 and if it's below that value then it's a 0.

Now the longer the cable, the more the signal degrades to the point when it's no longer possible to accurately distinguish between what should be 1s and 0s and at that point the picture will fail completely. Also timing the signals is absolutely crucial, if the timing slides out of tolerance again the signal collapses, at the high frequencies involved, the cable will act as an aerial radiating radio waves out and picking up interference. This is helped by twisting the pairs of wires in a particular way. Get the number of twists per meter wrong and again the signal can degrade faster than it should.

Bend the cable and one set of wires on the outside of the will stretch more than those on the inside. Bend it too much and the difference in length can (and does) cause timing errors. HDCP is particularly sensitive to this, if HDCP doesn't handshake properly (and it does it every two seconds) then you simply won't get a picture.

So we all need to go out any pay hundreds of pounds for cables? Well no. For most cases when we are only talking about a metre or so the tolerances in the cable specs are enough that any old £3 cable should work just fine. However I'd be tempted to pay a little more, say £10 or so to be a bit more reassured that the cable has been manufactured properly.

Certainly the two or three meter £200-£300 cables that you sometimes see for sale promising much better picture quality than a £20 cable are really taking the p**s but I just wanted to say that HDMI is actually a very complex system and the oft repeated, 'well it's digital so it either works or it doesn't; and a £2 cable is just as good as a £500 one' just isn't true. HDMI cable are NOT all the same but unless you are dealing with long lengths or are in a particularly noisy (electrically speaking) environment, you really don't have to go overboard.

 

[$ingh]

HDMI cables are digital and therefore only send ones and zeros. Unfortunately everyone is wrong. HDMI in common with all copper (and indeed wireless) signals are NOT digital, they actually carry an analogue waveform on which is superimposed a digital signal. In simple terms the voltages on the cables are constantly changing (hence analogue) if it's above a certain value then the receiving equipment interprets it as a 1 and if it's below that value then it's a 0.

Now the longer the cable, the more the signal degrades to the point when it's no longer possible to accurately distinguish between what should be 1s and 0s and at that point the picture will fail completely. Also timing the signals is absolutely crucial, if the timing slides out of tolerance again the signal collapses, at the high frequencies involved, the cable will act as an aerial radiating radio waves out and picking up interference. This is helped by twisting the pairs of wires in a particular way. Get the number of twists per meter wrong and again the signal can degrade faster than it should.

Bend the cable and one set of wires on the outside of the will stretch more than those on the inside. Bend it too much and the difference in length can (and does) cause timing errors. HDCP is particularly sensitive to this, if HDCP doesn't handshake properly (and it does it every two seconds) then you simply won't get a picture.

So we all need to go out any pay hundreds of pounds for cables? Well no. For most cases when we are only talking about a metre or so the tolerances in the cable specs are enough that any old £3 cable should work just fine. However I'd be tempted to pay a little more, say £10 or so to be a bit more reassured that the cable has been manufactured properly.

Certainly the two or three meter £200-£300 cables that you sometimes see for sale promising much better picture quality than a £20 cable are really taking the p**s but I just wanted to say that HDMI is actually a very complex system and the oft repeated, 'well it's digital so it either works or it doesn't; and a £2 cable is just as good as a £500 one' just isn't true. HDMI cable are NOT all the same but unless you are dealing with long lengths or are in a particularly noisy (electrically speaking) environment, you really don't have to go overboard.

Great Post, thanks.

 

[lee789]

Check this out I spotted it earlier ....

HDMI cheap or over priced makes no difference yet they try and sell them all the time because the retailers are money grabbing 's. I work in a large uk electronics's store and hate been told by my manager to lie to customers and sell the more expensive cables to make more money, This is really just make the store look good on the charts. If i and my colleges don't sell these cables we get moaned at hour after hour, now i just ignore all this myself and sell the required cable and if the customer wishes to spend more i will inform the customer that there is no need to spend more and to spend there hard earned cash on other things.

Now i can only speak for myself and can confirm that on a £99 cable the store will make around £70-90 profit and yes all staff earn commission on every thing howerver the managers are also told to inform staff that the products make little to no profit and to sell the extras to earn more money.

now the commision in store's is often very little usually 1% of the magin of the sales person's total sales and the company will usually find ways to take this away from them too on things like mystery shoppers store performance etc...

but remember this if you do buy high priced cables, product support (also unnecessary unless its a portable item ie laptop, camera etc...), Tv stands, sky. whatever the guy who sells you this equipment will receive praise from his manager and have a good day and when he has a review or possible promotion this stuff will help him massively in moving up the food chain.

Think that says it all....

many thanks

 

[nara]

COMING NEXT MONTH!!!!!!!!!!!

1 metre...$1000. Don't all rush at once.

Wireworld Introduces Flagship Platinum Starlight HDMI cable

 

[Firemouth]

HDMI cables are digital and therefore only send ones and zeros. Unfortunately everyone is wrong. HDMI in common with all copper (and indeed wireless) signals are NOT digital, they actually carry an analogue waveform on which is superimposed a digital signal. In simple terms the voltages on the cables are constantly changing (hence analogue) if it's above a certain value then the receiving equipment interprets it as a 1 and if it's below that value then it's a 0.

Now the longer the cable, the more the signal degrades to the point when it's no longer possible to accurately distinguish between what should be 1s and 0s and at that point the picture will fail completely. Also timing the signals is absolutely crucial, if the timing slides out of tolerance again the signal collapses, at the high frequencies involved, the cable will act as an aerial radiating radio waves out and picking up interference. This is helped by twisting the pairs of wires in a particular way. Get the number of twists per meter wrong and again the signal can degrade faster than it should.

Bend the cable and one set of wires on the outside of the will stretch more than those on the inside. Bend it too much and the difference in length can (and does) cause timing errors. HDCP is particularly sensitive to this, if HDCP doesn't handshake properly (and it does it every two seconds) then you simply won't get a picture.

So we all need to go out any pay hundreds of pounds for cables? Well no. For most cases when we are only talking about a metre or so the tolerances in the cable specs are enough that any old £3 cable should work just fine. However I'd be tempted to pay a little more, say £10 or so to be a bit more reassured that the cable has been manufactured properly.

Certainly the two or three meter £200-£300 cables that you sometimes see for sale promising much better picture quality than a £20 cable are really taking the p**s but I just wanted to say that HDMI is actually a very complex system and the oft repeated, 'well it's digital so it either works or it doesn't; and a £2 cable is just as good as a £500 one' just isn't true. HDMI cable are NOT all the same but unless you are dealing with long lengths or are in a particularly noisy (electrically speaking) environment, you really don't have to go overboard.

whole load to say, Cheap are as good as expensive. providing the are, true, HDMI licensed. (ie have the correct bandwidth). there will be no difference, indeed there can not be. providing all the signal get through, its not possible for there to be any. same goes for USB cables.

 

[Munkey]

Does anyone have any experience running very long HDMI cables of 10m 15m? I'd be very interested to hear your thoughts as I need to buy a load of different length leads.

edit - 15m is the max I need to go.

 

[little_pob]

Does anyone have any experience running very long HDMI cables of 10m 15m? I'd be very interested to hear your thoughts as I need to buy a load of different length leads.

edit - 15m is the max I need to go.

I know the HDMI 1.3c specs don't list a maximum length/run, but have you considered HDMI over ethernet?

 

[Munkey]

I know the HDMI 1.3c specs don't list a maximum length/run, but have you considered HDMI over ethernet?

I've seen 1.3c specced cable for around £40 for 15m, baluns cost about that so I'm thinking I should just lay the HDMI cable as it seems cost effective. I'm going to have to use one or two baluns anyway in zones where it's too late to change the cabling.

The problem is that I need at least 4 or 5 baluns but don't want to spend that kind of money.

HDMI over a network is so expensive