(Pocket-lint) – You might have seen HDMI eARC listed as one of the specifications of your new TV, AV receiver or speaker system but what does that mean?
We explain what HDMI eARC does and how it is different to HDMI ARC, which you might have also previously seen as a logo on home entertainment kit.
What is HDMI ARC and eARC?
Before we delve into eARC specifically, we’ll explain a bit about HDMI ARC.
ARC stands for audio return channel, with supported devices able to use a conventional HDMI connection to deliver and receive audio channels alongside video, rather than rely on a separate, dedicated optical digital audio connection.
An optical audio (TOSLINK) cable has one function – to deliver audio from your TV, say, to a receiver or directly to a speaker. It is good, clean and can downstream multiple channels of audio to your end device.
However, it is effectively dumb, and the amount of data it can carry is limited. Indeed, it is not capable of carrying high quality multichannel audio – such as Dolby TrueHD and DTS:X – nor can it carry Dolby Atmos tracks.
HDMI ARC, on the other hand, not only cleans up your cable management – needing only a HDMI cable coming out of the back of your TV – but also has greater bandwidth to play with. Admittedly, standard HDMI ARC is still limited in its output, with a maximum of 5.1 compressed audio channels able to be streamed from TV to soundbar, or a heavily compressed version of Dolby Atmos rather than the full-fat real deal, but it comes with other benefits.
For starters, you can use HDMI CEC, meaning you can shelve several remotes in favour of just the one – which can then be used to control your TV and other devices automatically. Plus, HDMI ARC has automatic lip-sync correction, which can be turned on or off.
Now onto HDMI eARC (enhanced audio return channel), which goes quite a bit further still. It has even greater bandwidth than conventional ARC, so can stream the more complex multichannel formats, such as Dolby TrueHD, DTS:X and, most notably, full bitrate Dolby Atmos.
It is worth noting that HDMI ARC is capable through ports from HDMI 1.4 and up, while HDMI eARC is generally only available through ports that carry the latest HDMI standard – HDMI 2.1 – although there are some exceptions.
How do I know if I have HDMI ARC or eARC on my TV?
Most TVs released in the last five years will offer at least one HDMI ARC connection on the rear, many soundbars and receivers too. You need to check either the original specifications for your device, or check around the back of your set.
Many devices will label a port to signify that it is supported – “HDMI IN – 2 (ARC)” or such like. Some sets and devices have ARC enabled on all ports.
HDMI eARC though usually requires a HDMI 2.1 port, so is mainly only supported by TVs and devices released from mid-2019 on.
There is an exception to the rule. Some eARC functionality works through earlier HDMI standards, if the manufacturer has pushed firmware to its sets/receivers/speakers to support it.
You need to check with your manufacturer to see if it has added support. But, again, it will only be on receivers and TVs from 2019 and up really.
Will all HDMI cables work with eARC?
Not all HDMI cables will be able to carry eARC compatibility. Some simply don’t have the bandwidth capable of carrying the extra audio channels and other benefits, along with 4K HDR video up to 120fps or even 8K video.
Most “high-speed” cables are fine though, as long as they have “Ethernet” support.
If you are worried, there are plenty of cables on the market now that claim to be able to carry 48Gbps and therefore eARC capabilities. They needn’t be expensive neither – with reasonably priced Ultra High Speed eARC compatible leads available on Amazon, for example.
Writing by Rik Henderson.