HDMI ARC, and its latest evolution, HDMI eARC, are two key audio technologies for today's best TVs, but you'll be forgiven for not knowing what that string of letters actually means.

It all depends on the audio output of your television and how it connects to sound bars and external audio systems. So if you're happy with its tiny 10W built-in speakers (or have one of the best TVs for sound), you probably don't need to read any further. However, if you plan to connect external audio equipment, it is a good idea to keep up with the inputs and technologies that allow you to get it right.

The ARC standard has been around for a while, connecting your TV and hi-fi into one entertainment system seamlessly and with fewer cables. Nevertheless, Thanks to the capabilities of the new HDMI 2.1 standard, eARC is now available to take audio to the next level.

Find out all about ARC and eARC, why you'll demand the latter, and which of the best TVs and audio gear currently on sale are about to feature eARC in our detailed guide below.

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What is HDMI ARC?

Audio Return Channel (ARC) is a type of audio transmission that connects your speaker's output to your TV's controls, via an HDMI cable, which means that you do not need a remote control or a remote control. Separate interface to manage the volume.

Of course, HDMI cables already carry audio from Blu-ray players, game consoles, and set-top boxes to a TV. But With ARC, they can also send audio the other way around, from a TV to an external speaker or sound bar, without having to connect a separate audio cable.

Ready to remove another remote from your already overly complicated home entertainment setup? Here's how to do it.


Why do we need ARC?

ARC is an often-ignored protocol that lies at the heart of almost all home entertainment products, and understanding ARC is knowing its "upstream" from its "downstream."

The first thing you need to know is that, As a feature of the HDMI specification, ARC allows a TV to send audio signals upstream to a sound bar, a connected monoblock home theater or AV receiver. It does this by first forming a "handshake" between the TV and the audio device, creating a two-way street for information.

By sending audio back and forth, ARC eliminates the need for optical audio cables (also known as S/PDIF), cutting down on unnecessary clutter that's probably already giving you a headache at home. Simply put, ARC is a cable killer.

Is my TV ARC compatible?

You probably must have a TV with a special ARC compatible HDMI slot, almost all TVs have had such a thing for years.

To find it, look at your TV's HDMI slot chain and you'll see that at least one has a little reference to ARC next to it.

An HDMI Licensing spokesperson told TechRadar: "An ARC-enabled TV can send or receive audio over HDMI, upstream or downstream, depending on system settings and user preferences."

This is usually automatic - use the ARC-ready HDMI slot on a TV and you can automatically send audio to any soundbar with an HDMI input.

There is also no delay. Lip sync functionality was introduced in HDMI 1.3 to ensure that audio remains perfectly matched to video. Since then, all HDMI standards have automatically compensated for processor delays, whether the audio is traveling up or down.


The humble HDMI cable brings the video and audio source to your TV, but eARC can bring the audio back (Image credit: iStock)

What is eARC?

What is the difference between ARC and eARC?

The next version of ARC, Enhanced ARC (eARC) is all about drastically increasing bandwidth for an expected increase in audio data.. eARC can handle more advanced audio formats and higher audio quality, being able to handle 32 channels of audio and even eight-channel 38-bit/24kHz 192Mbps uncompressed data streams. Thus, eARC supports Dolby TrueHD, DTS-HD Master Audio, Dolby Atmos, and DTS:X.

This means that the surround sound we hear is drastically improved.

Whether you're listening through a 5.1 system with separate speakers, a soundbar, or headphones, more nuanced, immersive sound is on the way. Thus, ARC evolves to eARC to manage it in the new HDMI 2.1 specification.

HDMI licenses also told us that "eARC simplifies connectivity, offers greater ease of use, and supports the most advanced audio formats and best audio quality."

What is HDMI 2.1?

HDMI 2.1 is the latest update to HDMI, which is for higher video resolutions and refresh rates. As well as being designed to handle the next generation of video: 8K resolution at 120 frames per second (HDMI 2.0 only handles 8K at 30 frames per second), HDMI 2.1 compatible TVs, Blu-ray players and game consoles will be able to handle superior images. speed up to 120 fps, even for 4K video.

Bandwidth of HDMI 2.1 cables will increase from 18 Gbit/s to 48 Gbit/s. Older HDMI cables may struggle with this type of data rate, but any newer HDMI cable is fine.

Today's Best HDMI 2.1 Cable Deals

HDMI ARC vs eARC Explanation of the return channel of

What televisions, AV receivers, and sound bars include eARC?

EARC is an increasingly common sight in today's television landscape, although you won't find it as often as its simpler ARC cousin.

However, all HDMI 2.1 certified products are eARC compliant, meaning that if you know your TV is using the first, you'll know it's also getting the second. Nevertheless, not all HDMI 2.1 ports will support it, as TV manufacturers tend to keep things simple by including only one eARC-compliant port, although there are four HDMI 2.1 inputs.

LG TVs have widely supported HDMI 2.1 and eARC since 2020, with four HDMI 2.1 ports on all of their OLED TV lines (except for the new entry-level LG A1 OLED, which is contained with HDMI 2.0). Today, newer Samsung TVs offer the same thing, while Sony is finally catching up with HDMI 2.1 support that was left behind last year. Panasonic is now embracing the technology in its 2021 TVs as well.

You won't find HDMI 2.1 and eARC on all TVs from these brands, although they are now expected on mid- and high-end models. Either way, we recommend that you check the specific model to make sure you get what you want.

However, to confuse things a bit, it appears that some features of HDMI 2.1, including eARC, but also ALLM (Auto Low Latency Mode) and VRR (Variable Refresh Rate), may be provided as a workaround on HDMI certified equipment. 2.0. Therefore, some 2020 and even 2019 TVs, AV receivers, and sound bars have had firmware updates to make these features active. However, check what each manufacturer supports and does not support before you buy.

EARC-compliant audio equipment, crucial if you want to enjoy eARC switching in a home theater setup, is more common, with firmware updates now available from Sony, Only, Pioneer and Integra for AV receivers and soundbars. recent.

HDMI ARC Specifications

What is Variable Refresh Rate (VRR)?

The HDMI 2.1 specification also includes some interesting but relatively unknown features, that could quickly become mainstream. Variable Refresh Rates (VRR) allow a TV to display a dynamic refresh rate in sync with the content, typically between 30Hz and 144Hz.

“I think it's going to be really great this year; there were a lot of demos at CES 2020, ”says Paul Gray, research director (consumer devices) at independent consulting and analytics firm Omdia. "A lot of content on the internet has really weird frame rates, like 73Hz, so it's not just games that will benefit." So expect more TVs to handle YouTube and web content better.

What is Auto Low Latency (ALLM) mode?

Another little-discussed element of HDMI 2.1 is Auto Low Latency Mode (ALLM), which is about creating a new and improved "game mode" for TVs.. Allows the TV to set the ideal latency (the delay when you refresh a web page or stream a game) to create smooth, lag-free viewing and interactivity. It can slightly degrade the image, so ALLM is not designed for movies (even real-time movies), but it is meant to bring a smoother feel to the game, especially with the release of the PS5 and Xbox series consoles. Next-gen X – and even video conferencing too.

For now, eARC is an emerging standard, but we're sure we'll see it dominate home entertainment soon.

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