HDMI ARC vs Optical: Which Has Lower Latency?

HDMI ARC and optical: two wired audio connections

HDMI ARC and optical are the two most common wired ways to send TV audio to a soundbar. HDMI ARC, which stands for Audio Return Channel, runs over an HDMI cable and carries both audio and control signals. Optical, sometimes called Toslink, uses a fiber optic cable to transmit digital audio as pulses of light. Both are digital, but they differ in how much data they can carry and how well they cooperate with your TV.

Optical has been used for decades and is simple to connect: plug one end into the TV, the other into the soundbar, and it works. HDMI ARC is part of the broader HDMI standard, which also carries video. The HDMI specification includes features that help devices communicate, such as Consumer Electronics Control and the enhanced gaming tools described on the HDMI Licensing Administrator site. These extra capabilities are directly relevant to audio latency. To understand the differences more deeply, you can read our comparison of HDMI ARC vs eARC.

What audio latency means for sync and gaming

Audio latency is the delay between the image on your screen and the sound from your soundbar. If the delay is long, you see lips move without hearing the words in time, or you hear impacts after the on-screen action has already happened. For movies, that breaks immersion. For games, it can make reaction to audio cues feel slow or disconnected.

HDMI's enhanced gaming features, which include Variable Refresh Rate and Auto Low Latency Mode, are specifically designed to reduce lag. These features let the TV and soundbar switch to a low-latency mode automatically, without you digging into menus. Optical connections do not carry these control signals, so they cannot trigger such automatic adjustments. Instead, you rely on the devices' internal processing, which can vary. If you are a gamer, you might also want to check our guide on soundbar game mode to see how to set it up.

Why HDMI ARC usually has lower latency

In most setups, HDMI ARC has lower latency than optical because it supports two-way communication. The TV can send timing information to the soundbar, and the soundbar can adjust its output to match the video. eARC, which extends ARC, adds more bandwidth for high-resolution audio and can further improve synchronization by reducing the need for compression.

Optical is a one-way connection. It sends audio from the TV to the soundbar, but it does not send any timing or command data. You have to adjust lip sync manually, and features like game mode may not activate automatically. That makes optical more prone to perceived delay, especially if the TV's processing adds its own lag before the audio exits the optical port.

A practical tip: if your TV has an HDMI ARC or eARC port, use it for your soundbar. This gives you the best chance of keeping audio and video in sync without extra effort. The difference may not be huge for casual viewing, but for gaming or dialogue-heavy content it can matter. For a curated list of soundbars with ARC support, see our best HDMI ARC soundbars.

When optical still makes sense

Optical remains a good choice for certain situations. If your TV lacks an HDMI ARC port, or if you use a projector that only has optical output, it is the only digital option. Optical also works with older hardware that predates HDMI ARC, making it a useful fallback for legacy devices.

The downside is that optical cannot carry the newest immersive formats, and it does not have the control features that help reduce latency. For stereo audio or Dolby Digital from broadcast TV, optical is fine. If you are willing to adjust lip sync manually and do not need game mode automation, you can still get a satisfying experience with an optical connection. To learn more about the differences in audio quality, check our article on optical vs HDMI.

How to reduce audio latency on any soundbar

No matter which connection you use, there are steps you can take to minimize delay. Here are the most effective ones, in order of importance:

• Connect via HDMI ARC or eARC whenever the port is available on both devices.
• Enable game mode on your TV and soundbar when playing games. Many sets switch to this automatically when they detect a console or PC.
• Turn off extra sound processing modes, such as virtual surround or upmixing, because they can add a few steps of processing delay.
• Adjust lip sync manually in the TV's audio menu if you still notice a gap. Some soundbars also have their own audio delay setting. For detailed steps, see our guide on lip sync adjustment.

What to pick for your use

Questions

Is HDMI ARC lower latency than optical?

Yes, for most setups. HDMI ARC supports two-way communication, which allows the TV and soundbar to exchange timing and control data. This enables automatic lip-sync correction and game mode activation. Optical is one-way and lacks those control signals, so it usually requires manual lip sync adjustment. Learn more about lip sync.

Does optical support Dolby Atmos?

No. Optical lacks the bandwidth needed for Dolby Atmos's full object-based audio. You need HDMI eARC to send Atmos from a TV to a soundbar. If your main goal is Atmos, use the HDMI connection.

How can I fix audio delay with optical?

Go into your TV's audio settings and look for a lip sync or audio delay option. Adjust it until the sound matches the picture. Some soundbars also have their own delay control. Turning off extra sound modes can help as well.

Does cable quality affect HDMI ARC latency?

Generally no. Digital cables either deliver the signal correctly or they do not. Latency is caused by processing and control features, not by the cable itself. A certified HDMI cable is all you need.

Can I use both HDMI ARC and optical at the same time?

You can connect both, but only one output is active at a time on most TVs. If you have HDMI ARC, use it first. Optical is a backup for when ARC is not available.