HDMI ARC vs eARC: enhanced audio return channel explained

HDMI ARC – and it is newest evolution, HDMI eARC – are each key audio applied sciences for as we speak’s finest TVs, however you would be forgiven for not realizing what these succession of letters really imply.

It is all to do with the audio output of your tv and the way it connects to exterior soundbars and sound methods. So in case you’re completely satisfied along with your tinny 10W built-in audio system (or have among the best TVs for sound) then you definately in all probability needn’t learn on any additional. Nonetheless, in case you ever plan on connecting any exterior audio tools, it is good to maintain abreast of the inputs and applied sciences that permit you to do it effectively.

Normal ARC has been round some time, connecting your TV and hi-fi tools into one, seamless and fewer cable-heavy leisure system. Nonetheless, due to the capabilities of the brand new HDMI 2.1 standard, now comes eARC to take audio to the next level.

Find out all about ARC and eARC, why you will one day demand the latter, and which of the best TVs and audio equipment on sale right now are set to feature eARC in our in-depth guide below.

What is HDMI ARC?

Audio Return Channel (ARC) is a type of audio transmission that links up your speaker output to your television controls, via an HDMI cable, meaning you don’t need a separate remote or interface to manage the volume.

Sure, HDMI cables already carry audio from Blu-ray players, games consoles and set-top boxes into a TV. But with ARC, they can also send audio in reverse, from a TV into an external speaker or soundbar, without having to attach a separate audio cable. 

Ready to remove one more remote from your already way-too-complicated home entertainment setup? Here’s how to do it.

HDMI ARC

 Why do we need ARC? 

ARC is an often ignored protocol sitting at the heart of almost all home entertainment products, and understanding ARC is all about knowing your ‘upstream’ from your ‘downstream’. 

The first thing to know is that, as a feature of the HDMI spec, ARC enables a TV to send audio signals upstream to a connected soundbar, a one-box home theater, or an 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 both ways, ARC does away with the need for optical audio cables (also called S/PDIF), cutting down on pointless clutter that likely already causes you a headache at home. Put simply, ARC is a cable-killer. 

  • Amped up about better audio? These are the best soundbars available today

Is my TV ARC-compatible? 

Probably. Although you do have to have a TV with a special ARC-ready HDMI slot, almost all TVs have had such a thing for years. 

To find it, look at your TV’s string of HDMI slots, and you’ll see that at least one has a small reference to ARC next to it.

A spokesperson for HDMI Licensing told TechRadar that, “An ARC-enabled TV can either send or receive audio via HDMI, upstream or downstream, depending on system set-up and user preferences.”

Usually it’s automatic: use the ARC-ready HDMI slot on a TV and you will automatically be able to send audio to any soundbar with an HDMI input.

There’s no delay, either. Lip-sync functionality was introduced in HDMI 1.3 to ensure that audio stays perfectly matched to video. All HDMI standards since have automatically compensated for any processor delays whether the audio is traveling upstream or downstream.

HDMI ARC

The humble HDMI cable transports video and audio source to your TV – but eARC can send the audio back (Image credit: iStock)

What is eARC?

What’s the difference between ARC and eARC? 

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

That means the surround sound we listen to is being substantially upgraded. 

Whether you’re listening through a 5.1 system with separate speakers, a soundbar, or via headphones, more immersive and nuanced audio is coming. So ARC is evolving into eARC to handle it in the new HDMI 2.1 specification. 

HDMI Licensing also told us that “eARC simplifies connectivity, provides greater ease of use, and supports the most advanced audio formats and highest audio quality.”

What is HDMI 2.1?

HDMI 2.1 is the latest update to HDMI, which is all about higher video resolutions and refresh rates. As well as being built to handle the next generation of video – 8K resolution at 120 frames per second (HDMI 2.0 only handles 8K at 30fps), HDMI 2.1-ready TVs, Blu-ray players and games consoles will be able to handle higher frame rates up to 120fps even for 4K video. 

HDMI 2.1 cables’ bandwidth will be upgraded from being able to handle just 18 Gbps to a whopping 48Gbps. Ancient HDMI cables may struggle with that kind of data rate, but any new HDMI cable is fine.

Today’s best HDMI 2.1 cable deals

What TVs, AV receivers and soundbars include eARC?

eARC is an increasingly common sight in today’s TV landscape, though you won’t find it as commonly as its simpler ARC cousin. 

However, all HDMI 2.1 certified products do support eARC, meaning that, if you know your television sports the former, you know you’re getting the latter too. Not every HDMI 2.1 port will support it though, as TV makers tend to simplify things by only including one eARC-enabled port, even if there are four HDMI 2.1 inputs.

LG TVs have roundly supported HDMI 2.1 and eARC since 2020, with four HDMI 2.1 ports on all of its OLED TV ranges (except the new, entry-level LG A1 OLED, which makes do with HDMI 2.0). New Samsung TVs these days offer the same, while Sony is finally catching up with the HDMI 2.1 support it lagged behind in last year. Panasonic, too, is now embracing the technology on its 2021 TVs.

You won’t find HDMI 2.1 and eARC on every TV these brands put out, though they’re now to be expected on mid-range and high-end models. In any case, we recommend you checking the specific model to make sure you’re getting what you want.

To confuse things a little, though, it seems that some features of HDMI 2.1 – including eARC, but also ALLM (Auto Low Latency Mode) and VRR (Variable Refresh Rate) – can be delivered as a workaround on HDMI 2.0-certified equipment. So some 2020 and even 2019 TVs, AV receivers and soundbars have had firmware updates to make those features live. However, do check what each manufacturer is or isn’t supporting before you buy. 

eARC-capable audio equipment – crucial if you want to indulge in eARC switching in a home cinema set-up – is more common, with firmware updates already available from the likes of Sony, Only, Pioneer and Integra for recent AV receivers and soundbars.

HDMI ARC specifications

What is Variable Refresh Rate (VRR)? 

The HDMI 2.1 specification also includes some exciting, but relatively unknown features that could quickly go mainstream. Variable Refresh Rates (VRR) enables a TV to show a dynamic refresh rate synced to the content, usually ranging from 30Hz through 144Hz. 

“I think this is going to be very important this year – there were a lot of demos at CES 2020,” says Paul Gray, Research Director (Consumer Devices) at independent analyst and consultancy firm Omdia. “A whole lot of web content material is in actually bizarre body charges like 73Hz, so it’s not simply gaming that may profit.” So anticipate extra TVs to deal with YouTube and web-sourced content material significantly better. 

What’s Auto Low Latency Mode (ALLM)? 

One other little-discussed a part of HDMI 2.1 is Auto Low Latency Mode (ALLM), which is all about creating a brand new and far improved ‘recreation mode’ for TVs. It permits the TV to set the best latency (the delay while you refresh an internet web page – or stream a recreation) to create easy, lag-free viewing and interactivity. It could degrade the picture barely, so ALLM shouldn’t be designed for motion pictures (even streamed motion pictures), nevertheless it’s destined to convey a extra fluid really feel to gaming – particularly with the launch of the next-gen PS5 and Xbox Collection X consoles – and even video conferencing too.

For now, eARC is an rising customary, however very quickly we’re certain to see it dominate dwelling leisure.