What is HDMI-ARC, Audio Return Channel, and how do I use it?

Whether you’re buying a new TV or looking through the specifications of your current one, you may find references to a feature called HDMI ARC, or Audio Return Channel. What is that, and what can you do with it? I’ll explain.

HDMI ARC: Adding more functions to a single cable

On its simplest level, ARC allows for audio to be passed both ways through an HDMI cable. To demonstrate how this can be used, I’ll use my own home theater system as an example.

I have my primary TV hooked up to several devices:

• a satellite receiver
• a Chromecast
• a BluRay disc player

This last also doubles as a sound system, having outputs for a complete 5.1 Surround Sound speaker and subwoofer set.

All the HDMI inputs have to go to the TV to be seen, but audio has to go to the BluRay player. Under conventional circumstances, I’d have had to run an additional fiber optic audio cable from the TV to the sound system, and then had to use a separate remote control to adjust the sound versus the remote I used to control the TV.

In fact, I’ve done just that in times past. But while wiring my newest TV, I took advantage of it being equipped with HDMI ARC. That means that the HDMI cable between the TV and the BluRay player can serve not only to take audio and video from the BluRay Player to the TV, but from the TV back to the player.

Using it is fairly simple: just connect an HDMI cable between the ARC-enabled port on your TV, and your sound system. You may have to make sure that using ARC is enabled in your TV’s settings; that will depend on your manufacturer. And your sound system may need to be told specifically to use the ARC input.

But aside from software settings, that’s all the installation required. The purpose of ARC is to make things simpler, thus, it eliminates the need for running an additional cable. That might sound small, but if you’re trying to keep things neat, one less cable is always good.

There’s another reason though that using HDMI for your audio is desirable.

ARC pairs well with another HDMI feature, Consumer Electronics Control

Another feature of HDMI that you might not be aware of is called Consumer Electronics Control, or CEC. CEC allows you to use your HDMI connections to pass commands from one device to another.

An easy example of this is allowing a satellite box to turn on the TV screen when the satellite is turned on, or a streaming stick being able to automatically change the TV to the proper input when activated. But there’s more that can be done with it.

In the case of my home theater, and others where HDMI-ARC is being used to drive a sound system or sound bar, CEC allows for the sound level and muting to be controlled from the TV–or, conversely, allow the TV to be controlled from the sound system.

Either way, it allows you to reduce the number of remote controls that you need to have around without needing to invest in a more expensive learning remote. Combining ARC and CEC means that my entire home theater system, with three main parts plus a Chromecast, all manages to operate seamlessly off a single remote.

Limitations and newer versions

There are a few things to be aware of when using HDMI ARC. For starters, most TVs feature only a single HDMI port that has ARC enabled.

In most cases, that’s not a problem, since you only need one ARC channel to drive your sound system. But if you already have your home theater set up, and find that the ARC port is plugged in to something else, you might need to do some reorganizing.

Early versions of ARC also were limited in what kind of audio they could pass along. Older sets can pass uncompressed stereo audio, or compressed 5.1 surround sound. Most people will find that adequate, but those with 7.1 systems or audiophile tendencies may not be satisfied.

Fortunately, the HDMI 2.1 standard introduced a newer, upgraded version of ARC. Called Enhanced Audio Return Channel, or eARC, it supports a wider array of audio formats. This includes uncompressed 5.1 surround sound, uncompressed 7.1, Dolby Atmos, and DTS:X.

Conclusion

HDMI ARC may not sound like a big deal, and it’s not something that all people will be able to find a use for. If you use your TV’s integrated speakers, or have a sound system which doesn’t come with an HDMI connector, ARC is fairly useless to you.

But for those situations where it does apply, it can greatly streamline the layout of your home theater system. In a niche where cables about and space is at a premium, that can be a big help.