With the launch of the new Apple TV 4K, cable manufacturers such as Belkin are rolling out HDMI cables they specifically claim are compatible with Dolby Vision, a flavor of high dynamic range (HDR) that delivers some of the best image quality available to compatible TVs.
Belkin's cable costs $30 for 6.6 feet (2 meters). Meanwhile Amazon Basics sells the same length for $7.
If you spent $180 on a new Apple TV, let alone $500 on the Dolby Vision-compatible Oppo UDP-203 4K Blu-ray player, an extra $23 might seem a small price to pay for a cable that claims to work perfectly with Dolby's format.
But you probably don't need a new cable for Dolby Vision, standard HDR or 4K. Here's why.
It's obvious when HDMI isn't working properly
There are lots of good and bad things about the HDMI connection, of which the cables are one part (your TV and a source are the two most common other parts). One of the better aspects is because of how HDMI works. If it works you get perfect picture or sound. If it doesn't work you don't get any picture or you get flickering, sparkles or other obvious visual degradation.
It's impossible for a "better" HDMI cable to make your video more colorful or more detailed. And you can't buy a "better" cable for improved sound quality. If it works, you get everything possible from the source. If not, it just doesn't work.
Any HDMI cable you've bought in the last few years is likely to be of the High Speed variety. This unfortunate name describes cables that can handle 1080p video and above. Chances are these cables will work for 4K and even 4K HDR. They are, essentially, a dumb pipe.
You don't need "special" HDMI cables to transmit HDR content. You just need a big enough pipe to handle the data. Over short distances, say six feet or around 2 meters, most cables will be fine. For longer distances the cable has to be a bit better made in order to work. But "better made" doesn't have to mean "expensive."
Here's the tricky part: There's no hard and fast rule about whether your particular High Speed cable will transmit 4K. It should work, but it it might not. Annoyingly, there's no way to tell just by looking at the cable. The only way is to test it with your TV and your 4K HDR source first.
What you do need for Dolby Vision
The first thing you'll require if you're upgrading to a TV with Dolby Vision capability is an Dolby Vision source. The easiest way to get this is via the apps built into your TV. They have the added advantage of not requiring any extra cables.
Many other Dolby Vision devices, including the new Apple TV 4K and 4K Blu-ray players like that Oppo, do require cables, as do any 4K switching devices like an AV receiver.
If you do buy this new gear, your current cables should work, and it's worth trying them first rather than letting a TV salesperson pressure you into getting a new one. The tradeoff, of course, is if that doesn't work you'll need to then either return to the place you bought them or buy them online. Saving money isn't always without risk.
If you've figured out that you definitely need new cables, there are countless inexpensive options. That $7 Amazon's Basics 6-foot HDMI cable "Meets the latest HDMI standards (4K Video at 60 Hz, 2160p, 48 bit/px color depth) that supports bandwidth up to 18Gbps." Which is to say, everything up to and including the HDMI 2.0b standard. Monoprice even has a 6-foot Premium Certified HDMI cable, that's essentially guaranteed to work, for only $4.50. Their 15-footer is $10.
CNET's David Katzmaier uses Amazon Basics cables in his TV test lab, and he had no issues getting them to pass Dolby Vision, including during reviews of the Apple TV 4K and the Oppo player.
So if you're in a store and someone says you have to get new cables for HDR or Dolby Vision, you probably don't.
Got a question for Geoff? First, check out all the other articles he's written on topics like why all HDMI cables are the same, TV resolutions explained, LED LCD vs. OLED, and more. Still have a question? Tweet at him @TechWriterGeoff then check out his travel photography on Instagram. He also thinks you should check out his best-selling sci-fi novel and its sequel.