HDMI vs. Optical: What Cable Should You Use?

To get audio from your TV to your soundbar or receiver you either need an HDMI cable or an optical cable. Both can work, but for certain types of audio you'll need an HDMI cable. Fortunately, both types of cables are inexpensive an easy to connect. For most people, we recommend just getting a cheap, high-quality HDMI cable. They'll work with just about everything, including the best TVs. 

However, if you have an optical cable gathering dust in that spare box of cables we all have, they'll work fine. Technically, HDMI is better, but on most systems, the difference will be minimal. There are some caveats to that, which I'll discuss. So here are the pros and cons of each connection type.

The basics of both

Both HDMI and optical pass digital audio from one device to another. Both are better than analog (the old-fashioned red and white cables). Both can pass multichannel audio, like Dolby Digital. Both cables are pretty cheap.

The biggest difference is that HDMI can pass higher-resolution audio, including the formats found on streaming services such as Dolby Atmos. These formats can't be transmitted using an optical cable.

In terms of simplicity, HDMI also passes video signals. So if you want just a single cable between two devices, HDMI (using ARC) is the best choice.

Optical is 'fine'

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.

One complication is if you have a soundbar that can benefit from a surround sound signal. Some TVs won't pass digital surround sound from their optical outputs. If your soundbar doesn't have HDMI, or you can't run HDMI, it's worth seeing if you can connect the bar directly to your source, like a Roku or Apple TV box, cable box, etc. 

When HDMI is best

The only way to get Dolby Atmos from your TV to a soundbar or receiver is via HDMI. Depending on how elaborate your audio system is, it might not do much with Atmos compared with the Dolby Digital sent via optical. On a decent home theater system, with quality speakers, you might get better surround sound, but the difference in the audio quality itself will be less obvious.

If you're setting up your system for the first time, it's worth just spending the few extra dollars and getting some HDMI cables. They're cheap enough, even over long distances, so there's no reason to use optical if you can avoid it.

Bottom line

Use HDMI when you can. They're cheap, and having just one cable for audio and video simplifies setup. If you can't, optical is fine. If your gear doesn't have HDMI, it can't take advantage of the Dolby Atmos anyway. On the other hand, Dolby Digital is surprisingly good, and unless you have decent, Atmos-capable gear, you probably won't hear much (if any) improvement with Dolby Atmos.

Note: This guide was first published in 2014 but has been updated with new links and info.

In addition to covering audio and display tech, Geoff does photo tours of cool museums and locations around the world, including nuclear submarines, aircraft carriers, medieval castles, epic 10,000-mile road trips and more.

Also, check out Budget Travel for Dummies, his book, and his bestselling sci-fi novel about city-size submarines. You can follow him on Instagram and YouTube.