HDMI ARC vs Optical: What are they and Which is best?

Speakers and audio for your TV have gotten both more complicated and easier to manage. Gone are the days of having to route cables all around the living room to get your speaker working and even running a 3.5mm cable from the headphone jack to the output isn’t even the simplest way to do things.

Oh no, now we can just plug in an HDMI cable or a singular optical cable and have the entire soundbar or speaker system working. The real question is, what are you going to be using? What does your hardware support? Do you even have the right cables for HDMI ARC?

HDMI ARC (Audio Return Channel) is a protocol introduced by the people behind HDMI (the HDMI Licensing Administrator, which if you’re ever curious, have a list of companies banned from using HDMI) with the 1.4 version of their cable.

It’s featured on some 4K and modern HD TVs, as well as soundbars or audio systems. If you have a look around the back, there’s a chance of your TV having an HDMI port labeled as ‘ARC’ or ‘eARC’, indicating you can take advantage of this feature.

Essentially, it allows you to take all the individual audio signals over the various HDMI connections going into your TV and pump them through your speaker via one HDMI cable. But the neat thing about it is that it works two ways.

With so many TVs coming built-in with their own version of Android or other software to launch apps directly off them without the need for FireTVs, Google Chromecasts, and Apple TVs, these TVs would usually have no way to send a signal down to the speaker without being directly plugged in via optical or audio cable.

HDMI ARC transmits the signal back down from the TV’s native apps (say if you hit the Netflix button that the TV manufacturer got paid handsomely for) to the same cable, meaning you’ve no need to run HDMI and another audio cable to hear the latest episode of whatever it is you binge.

There’s also the matter of CEC, or Consumer Electronics Control, which you might need to turn on in the settings of your TV, but often it’s automatically applied once the TV recognises ARC is in action.

CEC will talk to the speaker via the signal sent via ARC to turn on at the same time as the TV or turn off, so you don’t have to mess around with multiple remotes either. ARC is just a really good way of streamlining and simplifying down the whole setup.

New audio features like Dolby Atmos, 7.1 Surround Sound, and other Object-Based Audio require immense amounts of bandwidth that regular HDMI ARC can’t handle. So in 2019, eARC (Enhanced ARC) was deployed for HDMI 2.1, giving users access to a much more powerful protocol that can handle the new frontier of spatial audio.

It works in the same way, just through more powerful cables. eARC is usually labeled in listings or on the back of the TV, but won’t provide the unique features to speakers that are only ARC compatible. You’ll be able to listen to audio in the same way, just none of the brain-defying things that eARC can provide.

This is where we’re going to need to talk about HDMI and how your cables might be out of date.

If you’re into gaming and movies, you might already be up to date with HDMI’s entire shtick.

The shtick is that all your old cables might not be worth much of anything outside of 1080p these days. ARC requires high-speed, 1.4 HDMI cables, while eARC needs HDMI 2.1 cables. This distinction isn’t just in the updated model type, but the innards of the cables.

HDMI has begun incorporating Ethernet to assist with the transfer of data, so for eARC, you’re really going to need as much as you can get. Luckily, there are hundreds on the market, but future-proofing yourself with HDMI 2.1 will give you the opportunity to use 8K and in some cases, 10K, once they become consumer-friendly.

Now, HDMI is easy, but so is Optical! If you’re not on the latest tech, optical is still absolutely a killer method of connecting everything together via a singular cable. While not as fancy as ARC, one end in and one end out is simple enough.

While Optical does have its length limits, it’s not as severe as HDMI, mostly due to the innards being glass rather than copper. It shoots a beam of light with the information from end to end, also eliminating any interference from electricals around it. Because of this design, you can run it much further than HDMI around the house, making it perfect for projectors or unique setups,

So the question really boils down to what do you want? While all methods effectively do the same thing of passing audio from one end to the other, ARC’s features of working with your TV’s basic functionality and eARC’s advancements in bringing cinema level and spatial audio technologies are incredibly enticing, but this also means upgrading more than just a cable.

You might have a 4K TV, but it might not even have ARC on it. Your speaker or soundbar, also might not come with ARC. What could be a couple of tenners being exchanged over Amazon suddenly becomes an investment upgrade.

Meanwhile, Optical is fairly basic in what it can provide. Cheaper in hindsight when running long lengths, but ultimately can’t do much outside of providing a signal to your system.

However, you’ll also find that if you’re not someone who is in the mood for spending hundreds on upgrades for watching the latest on Netflix (or just the same reruns of what you’ve already seen), optical has been supported for quite a while now, meaning you probably already have a device that supports it!