HDMI vs. Optical: Which Digital Audio Connection to Use?
When hooking up an audio system or sound bar, you generally have to choose an HDMI or optical digital audio connection. Find out which one is better and why.
Geoffrey Morrison is a writer/photographer about tech and travel for CNET, The New York Times, and other web and print publications. He's also the Editor-at-Large for The Wirecutter. He has written for Sound&Vision magazine, Home Theater magazine, and was the Editor-in-Chief of Home Entertainment magazine. He is NIST and ISF trained, and has a degree in Television/Radio from Ithaca College. His bestselling novel, Undersea, and its sequel, Undersea Atrophia, are available in paperback and digitally on Amazon. He spends most of the year as a digital nomad, living and working while traveling around the world. You can follow his travels at BaldNomad.com and on his YouTube channel.
When it comes time to connect your shiny new soundbar or AV receiver, your two main choices are HDMI or optical digital audio.
The simplest advice is to go with HDMI when you can. But if you can't then it's not the end of the world.
Here are the pros and cons of each connection type.
Both HDMI and optical pass digital audio from one device to another. Both are better than analog (the red and white cables). Both can pass multi-channel audio, like Dolby Digital. Both cables can be had pretty cheap.
Depending on your gear, you might not have the option for HDMI. Maybe you have an older receiver. Maybe you have everything connected to your TV, and you just want to get the audio out to a soundbar (and the only option is optical).
In that case, optical is fine. Don't sweat not being able to connect with HDMI. For most setups, the sound will be just as good with optical as with HDMI.
Regardless of the gear you use, as mentioned there's also no way to get Dolby Atmos or DTS HD Master Audio with an optical connection. However, that's not a huge deal.
While there is a difference between Dolby Digital and those high-res lossless formats, the difference isn't as pronounced as you might expect. On a decent home theater system, with quality speakers, you might notice that the high-res formats are a little more open, a little smoother sounding.
On lesser gear, it's a lot less likely you'll hear a difference. Most soundbars, for example, lack the fidelity to do anything with the additional resolution. Many don't accept those formats at all.
Use HDMI when you can. The cables are cheap, and having just one wire simplifies setup. If you can't, optical is fine. If your gear doesn't have HDMI, it can't take advantage of the high-resolution audio formats from streaming services anyway. On the other hand Dolby Digital is surprisingly good, and unless you have decent gear, you probably won't hear much (if any) improvement with Dolby Atmos and DTS HD MA.