HDMI Investigated - Are expensive cables a scam?
What's the difference in performance between a £5 HDMI cable and a £100 one? We find out
Expensive HDMI cables have been a bit of a hot topic for us, and the consumer electronics industry as a whole, for some years. Some believe they're a waste of money; it's a digital cable, so either it works or it doesn't. Others claim there's potential for subtle variations in performance, while some insist that there's a huge gulf between the picture and sound quality from cheap and expensive cables, and that the differences are easy to spot. So who's right?
Are the proponents of expensive HDMI cables falling for cynical marketing ploys? Are the detractors doing their TVs a disservice? There are two approaches to settling this issue. One is to look at the technology to see whether it backs up either argument. The other is to put people in front of TVs and conduct blind trials. In this feature, we'll do both. First, though, let's look each camp's claims in greater detail.
THOSE IN FAVOUR
Various home cinema magazines and websites make it clear where they stand. Home Cinema Choice reviewed the Ixos Studio XHT288, which costs £45, in its February 2008 issue: "There are a few who believe that, as they're digital, all HDMI cables are the same regardless of cost and build. They're wrong. The XHT288 1.0m cord cements this claim by providing a spectacularly foible-free and clean stream of video and audio."
The reviews at What Hi-Fi? Sound and Vision's website cover cables from £1 to £300. At the top end is the van den Hul Ultimate, which receives five stars for its "clear, detailed, realistic picture". The Monkey Concept 5m (£77) doesn't fare so well, scoring just two stars. According to the review, "contrasts here are washed out, with the sunny brightness of the Shire in The Fellowship Of The Ring looking distinctly overcast, and skin tones having the caste of a freshly embalmed corpse. Images too, aren't as crisp as we'd like, with fuzziness and noise creeping in throughout."
Not all reviewers share this view. At www.avreview.co.uk, a group test of six HDMI cables costing from £30 to £240 concludes, "Not even a blind comparison test … could reveal any obvious differences in performance between these interconnects." The biggest advocates for premium HDMI cables are the companies that make them. However, the claims on their websites focus on superior components and construction rather than improvements to picture and sound quality.
Robust construction is an easy argument to understand. HDMI cables are rarely plugged and unplugged, but regular scrabbling around behind the TV might prove too much for a weak HDMI cable. A robustly constructed cable also makes sense for installations where the cable runs under floorboards or behind plaster, where replacing it would be a serious hassle.
What about picture and sound quality, though? We asked various premium HDMI cable manufacturers whether they agreed with assertions that some HDMI cables achieve better contrast, better skin tones, less noise and a sharper picture than others.
Nick Allen from The Multi-Room Company, which distributes AudioQuest HDMI cables in the UK, told us, "We have taken AudioQuest's four main HDMI cables … demonstrated them using both music and movies and … let the dealers comment on what they thought – without exception, it is agreed that audio performance gets increasingly better with each step up in the range, as does picture."
We also spoke to Abbas Hussain, managing director of WireWorld UK. His view is that, "You can't swap [an HDMI] cable and get better contrast. However, if you were to say that the picture looks cleaner – yes, that is possible."
Rob Follis, who represents Ixos and Supra, wouldn't be drawn on the subject: "I've seen so many things that started off as being magic and people joking about becoming accepted parts of the mainstream – I'm slightly dubious but I don't discount the possibility." Elliot Davis, MD of Ecosse, simply said, "This is a most contentious issue which requires much consideration."
THE ARGUMENTS AGAINST
The issue is simpler for those who believe that cheap HDMI cables are just as good as expensive ones. As the data is digital, either the cable works or it doesn't. If you can see the picture and hear the soundtrack, you've got the best quality you possibly can from an HDMI cable.
For them, any arguments about oxygen-free copper conductors and silver-plated contacts are red herrings. Premium cable manufacturers tend to be the same companies that have been making analogue video and audio cables for home-entertainment enthusiasts for many years. It's easy to understand why they would want to apply their expertise – and high prices – to HDMI cables, but that doesn't necessarily lead to better performance. The fact that many high-street retailers stock only HDMI cables costing £30 or more reinforces suspicions that manufacturers and retailers are taking customers for a ride.
Let's make one thing clear. An HDMI cable can't improve the quality of the video and audio travelling through it. The digital signal consists of zeros and ones, so you'd need active electronics to process the data to generate more attractive video and audio, outputting it as new zeros and ones. In other words, the best a cable can do is to transmit the signal without any errors.
The idea that digital cables are impervious to errors doesn't hold water either. The data is encoded digitally but it still has to travel down the cable as an electric signal that's susceptible to degradation from the cable itself and interference from other electric devices.
Everyone seems to agree that lots of errors can lead to an unwatchable picture, with dropped frames, glitchy audio and a complete loss of picture. There are also widespread reports of 'sparklies', where errors result in white pixels that resemble digital snow flickering across the screen. The common feature in all these problems is that they're impossible to ignore. No-one who uses cheap HDMI cables would unwittingly put up with these errors.
So the heart of the matter is this: is it possible for an HDMI cable to introduce errors that cause subtle problems, which some people may not notice but others will be willing to pay a premium to avoid?