What you need to know about HDMI ARC and eARC

One of the easiest ways to hook up a home theater receiver or powered sound system to your 4K TV is HDMI. This is the type of connection that most sound bars and surround sound speaker systems use these days. But not all HDMI connections are created equally.

If you have a couple devices to hook up and want to avoid a mess of wires, you'll want to use a port labeled "ARC" or "eARC." But what do those labels mean and how do they make your setup simpler?

Let's dig in.

What is HDMI ARC?

ARC stands for "Audio Return Channel." This type of HDMI port was introduced way back in 2009 and has become an industry standard. Without ARC, HDMI is able to transmit both audio and video signals, but this transmission only goes one way.

If you're only connecting a single device like a sound bar, that might be fine. But if you have a source hooked up to your sound system or receiver, like a gaming console or Blu-ray player, you'll need an extra cable to carry the sound back out, too. (Usually, via an optical digital audio cable.)

With ARC, you're able to pass picture and sound to your TV from a connected source and send an audio signal back to your sound system or receiver from the TV. That means even if you have multiple sources hooked up to your receiver, you still only need the one HDMI cable going to your TV.

How does ARC make setup cleaner?

A one-cable ARC setup is great because you don't need as many cables dangling from your TV. You can connect to your receiver or sound system out of sight below your TV, then only worry about running the one cable up to the TV.

It's especially great if you have your TV wall-mounted. Cable management is a lot easier. You can install a simple cable track or raceway. Or, you could run a single in-wall rated HDMI cable totally out of sight behind the wall, for a super clean look.

ARC lets you connect your sound bar to your TV with a single cable. Hook your other gear up to the bar or TV, but pick one. To avoid a headache, don't mix and match.

Do I need special HDMI cables for ARC?

ARC is compatible with HDMI versions 1.4 and above. Most HDMI cables available today are at least compatible with version 2.0. The latest version of HDMI is 2.1, which can pass the highest bandwidth yet. It also supports the enhanced version of ARC: eARC. More on that soon.

If you need help picking out the right HDMI cable, our buying guide has you covered.

HDMI ARC vs. an optical digital connection

A Toslink optical digital audio cable can only pass your sound. And it's always one-way. That means you can output audio from your TV to another device with this kind of cable, but that's it.

Optical digital also has a lower bandwidth than more recent versions of HDMI, which means there are some high-bandwidth audio formats, like Dolby Atmos or DTS:X, that you can't pass with it.

ARC works with HDMI versions 1.4 and up, while eARC requires 2.0 or higher. The latest and highest bandwidth version of HMDI is 2.1.

ARC vs. eARC

eARC stands for "enhanced Audio Return Channel," which begs the question: if ARC lets you hook up your receiver or sound system with a single HDMI cable, what exactly is being enhanced? The short answer is that eARC has a higher bandwidth and bitrate.

A higher bandwidth means eARC can send and receive more information than a standard ARC port. A higher bitrate means that data can also be passed faster. Both of these are key if you want to get the most out out of uncompressed surround sound audio formats like Dolby Atmos or DTS:X.

eARC also provides a more reliable "handshake" between devices. This keeps things like HDMI CEC working smoothly, so you don't need a bundle of remotes nearby. A built-in protocol for Lip Sync Correction keeps your picture and sound lined up, too.

Do I need eARC for Dolby Atmos?

Yes and no. ARC has a lower bandwidth, which prevents it from passing an uncompressed Dolby Atmos signal. But that doesn't mean you can't get Atmos at all. You'll just lose some of the data from Atmos or other high-quality audio formats.

Fortunately, most streaming services use a compressed or "lossy" version of Dolby Atmos, which ARC will work with. The lossless signal provided by a Blu-ray, however, will be more than a standard ARC port can fully take advantage of.

eARC will net you higher audio quality than ARC because it's retaining the full Atmos signal. And its support for a higher bitrate means that you're less likely to experience audio lag — which is a big deal for gamers like myself. Even a small delay can throw off your timing and cause you to miss key audio cues.

So, if you want to send the highest-quality Atmos signal to and from your TV, we recommend HDMI eARC.

The higher bandwidth of eARC will let you pass a full, uncompressed Dolby Atmos signal for greater sonic detail and immersion.

Setting up with ARC or eARC

Getting started with an ARC or eARC connection is as easy as "1-2-3" and you only need the one HDMI cable.

1. Make sure you've got the same type of HDMI port on both ends: ARC to ARC or eARC to eARC.
2. Plug in your HDMI cable to your TV's ARC or eARC port.
3. Plug that same HDMI cable's other end into your receiver, sound bar, or other device's ARC or eARC port.

Most devices automatically recognize when you're plugged into the ARC or eARC port. The story ends there. But if you have an older TV, you may need to hop into your settings and manually switch to ARC mode.

Plug in your HDMI cable to the HDMI ARC or eARC port on the back of your sound bar and match it with the same port on your TV or receiver. It's that easy!

Do I need a new HDMI cable?

That depends on what version cable you have. Version 1.4 or higher is good enough for ARC. But you'll need Version 2.1 for eARC.

We can help!

Still have questions or just need a little guidance finding exactly what you’re looking for? You can always get in touch with one of our friendly Advisors. And don't forget free lifetime tech support is included with your Crutchfield purchase.