If you’ve bought a TV in the last few years, then you may see labels on the set itself or mentions in the settings of HDMI ARC. It’s an easy feature to miss, but one that could very useful if you prefer to use a soundbar or stereo system to pump out the audio from shows and movies.
We explain what this mysterious technology does, why you should consider using it, and how the new eARC variant could improve things even further.
What is HDMI ARC?
For a fair while now, HDMI has been the standard way of connecting your TV to set-top boxes, streaming devices and games consoles, replacing SCART cables that previously dominated proceedings. If you want to hook up a soundbar or play the audio from your TV through a Hi-Fi, then in most cases it will be via an optical cable unless your device had a specific HDMI output port.
The reason for this is because most standard HDMI ports found in TVs are inputs, designed to receive signals from the aforementioned devices and display them on your screen. But, to send the audio to an external speaker it requires an output, hence the need for a dedicated port.
HDMI ARC (Audio Return Channel) is a more advanced version of HDMI that is capable of carrying data and audio in or out of your TV. This means you can connect those soundbars, home theatre, and compatible audio systems using a normal HDMI cable.
But, isn’t that just the same as a dedicated output port? Well, in some ways it is, as you would connect it into an external speaker, but it can also act as a standard HDMI port if you need to attach another device instead.
On the audio side, due to the upgraded nature of HDMI ARC, it also goes a long way to fixing lip-syncing problems that can occur with optical and coaxial cables, plus it also works with the CEC (Consumer Electronics Control) setting found in many modern sets to enable users to control both the TV and audio devices with the same remote.
What are the drawbacks?
Much like with USB-C, there are certain things that need to be included for something to be HDMI ARC, but manufacturers are still free to omit other features or audio codecs which they deem unnecessary. This means that the standard isn’t exactly standard, which can lead to issues when connecting devices from different brands.
So, to be sure of the kind of audio output you can get from your TV you’ll need to refer to the manual or do a quick Google search to avoid disappointment when you expect 5.1 Dolby but only hear stereo.
How do I know if my TV has HDMI ARC?
Take a look at the back of your set and find the various HDMI ports. If you see one that includes the letters ARC then that means you’re in luck. Most sets released in the last few years should have at least one.
What is HDMI eARC?
As HDMI has been around since the early 2000s, the technical demands of modern 4K video and high-quality audio are now too much for the original version to handle. In 2013 HDMI 2.0 made its debut, bringing support for 4K UHD at 60fps, with subsequent minor upgrades that added HDR (High Dynamic Range) and HLG (Hybrid Log Gamma) capabilities.
This has been replaced by HDMI 2.1 that can deliver 4K at 120fps, 8K at 60fps and even supports 10K video. What makes this all possible is the huge amount of bandwidth now available, maxing out at 48Gb/s.
Taking advantage of this, ARC has also received an upgrade in the form of eARC with the additional letter standing for ‘enhanced’.
This means that compatible devices will be able to output the likes of Dolby Atmos, Dolby TrueHD, DTS:X and other high-end audio to home theatre receivers and speaker systems.
Will my equipment need to support eARC and HDMI 2.1?
Up until very recently there have been no TVs available that support the new standards, and as the features are hardware-based there’s no way to upgrade older models.
This year’s Consumer Electronics Show (CES) was the first time that new TVs with HDMI 2.1 and eARC capabilities were unveiled to the public, with impressive devices like the Sony Bravia KD55AF9 and LG OLED65C9PUA giving an indication of what we can expect going forward. One thing is very clear, to enjoy the new standards you’ll be spending quite a lot of money, at least for a year or two.
If you’re not too bothered about eARC, then take a look at our best TVs roundup for the pick of the crop that can still deliver HDMI ARC technology.