Should I use HDMI ARC or Toslink to connect my soundbar to my TV?

When hooking up a sound bar, you generally have to choose a HDMI or optical digital-audio connection. Find out which one is better and why.

I'm not addressing a whole bunch of variables and assume you have an HDMI ARC (out) available on your soundbar and a HDMI ARC (in) on your TV as well as optical (Toslink) on both.

The Basics

Both HDMI and optical pass digital audio from one device to another. Both are better than analog 1 (the red and white cables). Both can pass multi-channel audio, like Dolby Digital. Both cables can be pretty cheap.

The biggest difference is that HDMI can pass higher-resolution audio, including the formats found on Blu-ray: Dolby TrueHD and DTS HD Master Audio. These formats can't get transmitted across optical.

In terms of simplicity, HDMI also passes video signals. So if you want just a single cable between two devices, HDMI is your pick.
With HDMI ARC the volume control should also be simplified. I use the LG Magic Control to control the sound on my JBL Bar 5.1 soundbar.

ARC

ARC, or Audio Return Channel, is an HDMI feature, built into many TVs, receivers, and sound bars. It has the potential to simplify the setup. Apparently some TV manufacturers haven't implemented ARC to send any and all audio via HDMI. Want to hear 5.1 surround from your receiver? ARC might not let you do it. Many TVs are two-channel (2.0) only via ARC. I have a LG 65ub9500 and it passes all the signals (like Dolby Digital) successfully to my JBL Bar 5.1 soundbar.

However...

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 sound bar (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 sound bar, like the Sonos Playbar or Vizio S4251w-B4, that benefits from a surround sound signal and you connect it to one of the many TVs that can't pass such a signal via its optical outputs. Neither of those sound bars have HDMI inputs anyway, so the best way to connect them is directly from the source to the bar via optical, skipping the TV. That, or get a new TV.

So even if you've got a great surround sound movie, and a receiver with 5.1 speakers (or a sound bar with rear speakers), connecting them with ARC might mean you're only going to get audio for the main two speakers.

Some TVs will send 5.1 if the TV is the source of the audio (either from a streaming app or the built-in over-the-air tuner), but won't pass 5.1 from other sources, like a Blu-ray player.

Also, ARC only passes Dolby Digital. So those new high-resolution audio formats available on Blu-ray discs, namely Dolby TrueHD and DTS-HD, are unavailable over ARC. This isn't the TV manufacturers' fault, but it's still annoying.

If you're lucky, a TV's ARC implementation will be described in the manual, which is usually easy to find on the manufacturer's websites. Unfortunately, TV manuals often skip this information.

Everything in the chain

Just because your TV is ARC-compatible, that doesn't mean you can use it. Your receiver and sound bar have to be as well. Fortunately, most new TVs, receivers, and sound bars have an input that has ARC.

Bottom line

Audio Return Channel is convenient and can simplify your setup. However, it might also mean you don't get surround sound, and it definitely means you won't get the high-resolution audio formats from Blu-ray.

Footnotes

  1. When I say both are better than analog, it is in reference to this article for the connection between an standard modern TC and standard mainstream soundbar. If you have some special soundbar, and the signal is coming from a device like an amp, then obviously different rules apply.