If you’ve ever tried to plug more than one or two devices into a TV, you know how quickly home theater issues can get complicated. While HDMI cables make connections somewhat simpler, they introduced nearly as many problems as they tried to solve.
Audio is a particularly tricky problem with HDMI, since audio and video are sent over a single cable. HDMI Audio Return Channel (or HDMI ARC) is meant to keep your home theater setup a little simpler. Let’s take a look at how it works and what it can do for you.
What Is HDMI ARC?
HDMI is supposed to make getting your audio video devices connected easier. We used to need anywhere from two to five connection points and often multiple cables for even the simplest connections. HDMI brings this down to one cable in many cases.
If all you’re looking to do is hook up a Roku to your TV, using a single HDMI makes things much simpler than they would have been in the past. This assumes that you’re just using the built-in speakers on your TV.
Say, for example, you’re using a soundbar. This is where things get a bit more complex, especially if you want to use your Roku remote to control the soundbar’s volume. This is what two different HDMI technologies—ARC and Consumer Electronics Control (CEC)—were designed to solve.
CEC basically allows your remote to pass signals to other devices like streaming boxes and Blu-ray players over your HDMI connections. Theoretically, this means that you may be able to control every device hooked up to your TV with a single remote control.
ARC, on the other hand, makes sure all your audio goes to the same place, no matter where it comes from. This may sound simple, but it isn’t.
How HDMI Audio Return Channel Works
Before ARC, if you wanted all of your audio to play through a soundbar or A/V receiver, you needed to route your devices through the soundbar or receiver, then to the TV. This also means that not only does your TV need to support 4K, HDR, or any other new technologies, but your receiver does as well.
The audio return channel uses a single port to handle all audio, both to and from a given device. This means that you can plug in a soundbar to one HDMI input on your TV, and audio from any devices on other devices will automatically play through that soundbar, without any extra configuration on your part.
At least, that’s how it’s supposed to work. As with most technologies related to home theater, HDMI ARC has issues. For example, you may run into issues where the audio and video don’t sync up perfectly because of latency in the connection.
There are plenty of other problems that you can run into, but before we get to that, let’s look at making those connections in the first place.
Getting Started With HDMI ARC
In order to use HDMI ARC, your TV needs to support it. Usually, you can tell by looking at the HDMI ports on your TV’s back or side. If your TV supports ARC, one port (usually HDMI 1) will be labeled ARC. If you’re in doubt, check the manual or the manufacturer’s website.
Your soundbar or A/V receiver also needs to support ARC. As with a TV, you should be able to tell by looking on the back, though it’s slightly simpler since most receivers or soundbars only have one or two audio out ports. Look for the HDMI Out port, and it should be labeled ARC.
Once you’re sure both your TV and soundbar or receiver support HDMI, it’s a simple as running a cable between the two marked ports. Then plug any other devices into your TV.
Do You Need An HDMI ARC Cable?
For the most part, you don’t need a specific HDMI ARC cable to use ARC features.
Any HDMI cable will handle the original ARC spec, though some of the newer features eARC brings will require a newer cable. Now, speaking of eARC, let’s take a look at what that brings to the table.
eARC: Fixing HDMI ARC’s Problems
One of the main problems that HDMI ARC was supposed to solve was needing to run an optical or coaxial cable from your TV to your receiver or soundbar for digital audio. While ARC does indeed solve this problem, it doesn’t solve it completely, as it may not necessarily be able to pass 5.1 audio.
This will come down to your TV. Some TV’s support standard Dolby or DTS 5.1-channel audio over HDMI. Others only pass stereo audio over HDMI. This is left up to manufacturers because 5.1-channel audio over HDMI isn’t featured in the HDMI spec.
Enhanced Audio Return Channel or eARC solves this. With eARC, not only is 5.1-channel audio passthrough supported, but newer surround sound technologies like Dolby Atmos and DTS:X are as well.
As to whether or not you can make use of the benefits of eARC, that’s where you’re going to need to start checking your TV, receiver, and cables. The benefits of eARC were introduced as part of the HDMI 2.1 specification, which means you need HDMI 2.1 support across your devices to make the most of it.
This is where your cables can start to get in the way. HDMI 2.0 and up require higher bandwidth and, as a result, cables that can support this bandwidth. HDMI cables don’t often make it easy to tell what version they are, but HDMI 2.1 TVs only started to appear in 2019. So, if your cables are a few years old, you probably need to replace them.
HDMI Isn’t Always the Answer
As you’ve probably already encountered at some point, HDMI can have plenty of problems beyond those either caused or solved by ARC. We’ve definitely come a long way since the days of RCA composite and component connections, but there is still a way to go.
Depending on what you’re trying to do, HDMI may not be the ideal connection for your display. Don’t just assume that simpler is better—make sure to investigate all your connection options when you’re setting up your gear.
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