Soundbar Audio Latency: How Many Milliseconds Is Acceptable?

What is audio latency?

Audio latency is the delay between the moment a signal is generated or received and the moment it is played through the speakers. In soundbars, this delay usually comes from signal processing, wireless transmission, or the audio decoding steps. Even a small delay can be noticeable when you watch video, because your eyes and ears expect sound and picture to arrive together.

Latency is measured in milliseconds (ms). One millisecond is a thousandth of a second. Human perception of audio-visual sync varies, but most people notice when audio lags video by more than about 50 to 100 ms. For dialogue, even 30 ms can feel slightly off to some viewers. As a rule of thumb, you want latency under 40 ms to stay in the comfortable zone.

Why latency matters: lip sync and gaming

When audio arrives after the video, characters’ lips move before you hear the words. That effect is called lip sync error. It is distracting in movies, TV shows, and especially in news broadcasts where people talk directly to the camera. Even a small delay can make dialogue feel unnatural. You can read more about correcting it in our article on lip sync adjustment.

In gaming, audio latency directly affects reaction time. If you fire a weapon and hear the shot a fraction of a second later, you may miss a cue. Competitive players want the lowest possible latency. Some soundbars offer a dedicated game mode that reduces processing delay. Check our guide to game mode for more details.

Where does latency come from?

Soundbars process audio in several steps. The digital signal may be decoded from Dolby Atmos or DTS, passed through equalization and room correction, and then converted to analog. Each step adds a few milliseconds. Wireless connections between the main bar and rear speakers or subwoofers can also introduce delay.

The connection type matters. HDMI ARC and eARC carry audio in a digital format with low overhead. Optical (TOSLINK) can also have low latency, but it lacks the bandwidth for object-based audio. Bluetooth is the most problematic for latency because it uses data compression and buffering to maintain stable playback. The Bluetooth technology overview describes that the Classic radio supports point-to-point streaming for audio, but the buffering required by the protocol adds delay.

What latency is acceptable?

There is no single number that works for everyone, but as a rule of thumb, keep audio latency below 40 ms. At that point, most viewers do not notice a lag. If you want a more forgiving experience, aim for under 25 ms. For competitive gaming, you may want even less. These are guidelines, not firm standards, and your personal sensitivity matters more than any fixed value.

Latency also depends on the content. Fast action movies and games are more sensitive to delay. Dialogue-heavy scenes are less forgiving because lip sync errors are apparent. If you are sensitive to sync issues, you may prefer a soundbar with a low-latency mode and support for HDMI eARC. The HDMI specification includes features like Auto Low Latency Mode (ALLM) that automatically reduce processing delay when you switch to a game.

How to reduce audio latency

Start with the connection. Use HDMI eARC when your TV and soundbar support it. eARC is designed to handle high-bitrate audio and automatic lip sync information. You can learn more in our comparison of HDMI ARC vs eARC. If you must use optical or Bluetooth, look for a soundbar with a dedicated low-latency mode. Many models include a game mode or a lip sync adjustment.

You can also adjust the lip sync setting on the TV or soundbar. Most modern sets let you manually set a delay to align the audio and video. Some soundbars offer automatic lip sync correction based on the HDMI eARC connection. Check the firmware updates and settings menu for these options. Our guide on correcting lip sync on your TV walks through the steps.

• Use HDMI eARC as the primary connection.
• Enable the soundbar's low-latency or game mode.
• Turn off audio post-processing like virtual surround when latency matters.
• Update the soundbar firmware to fix sync bugs.
• Manually adjust the TV's audio delay option if needed.

What to look for when buying

When you compare soundbars, pay attention to the connection panel and advertised features. Look for HDMI eARC support, a low-latency game mode, and firmware that can be updated. Avoid models that rely only on Bluetooth for the primary connection, because Bluetooth adds noticeable delay. The Bluetooth technology overview confirms that Classic radio is used for wireless audio, but the buffering needed for stable playback inherently increases latency.

Also consider the number of channels and whether the soundbar includes rear speakers. If you plan to play games, a model with HDMI 2.1 features like ALLM can be beneficial. ALLM automatically switches the display and audio components into a low-latency mode when you start a game. The HDMI Forum lists ALLM among its enhanced gaming features. For a complete comparison of channel configurations, see our guide to soundbar channel numbers.

What to pick for your use

Questions

How many milliseconds of audio delay is noticeable?

Most people begin to notice lip sync errors when audio lag exceeds 40 to 50 ms. Delays below that are generally considered acceptable. The threshold varies by individual and content type, so using a low-latency connection like HDMI eARC is the safest choice.

Is Bluetooth too slow for soundbars?

Bluetooth adds noticeable latency because the audio is compressed and buffered to maintain a stable stream. It is fine for music listening, but not ideal for movie watching or gaming where lip sync matters. If you must use Bluetooth, look for a soundbar with a dedicated low-latency codec such as aptX LL, though it is still not as fast as a wired HDMI connection.

Can I fix audio delay on my soundbar?

Yes. First, switch to HDMI eARC if you are not using it. Then enable the soundbar's game mode or low-latency setting. Many TVs also have a lip sync adjustment under audio settings. If the problem persists, updating the soundbar firmware can resolve known sync bugs.

Does Dolby Atmos processing add latency?

Decoding Dolby Atmos adds processing time, but the delay is usually small, often a few milliseconds. The larger latency comes from wireless transmission or audio post-processing. A soundbar that supports Atmos over HDMI eARC can keep latency lower than one that relies on Bluetooth for the primary connection.

Should I use optical or HDMI for latency?

HDMI ARC and eARC are better than optical for latency because they support automatic lip sync signals and higher bandwidth. Optical can still work, but it lacks the capabilities for object-based audio and may require manual delay adjustment. If you want the lowest latency possible, use HDMI eARC.

What is Auto Low Latency Mode (ALLM) in soundbars?

ALLM is an HDMI 2.1 feature that allows a source device, like a game console, to automatically switch the display and audio equipment into a low-latency mode. The HDMI spec includes ALLM as part of its enhanced gaming features. When your soundbar supports ALLM, it reduces processing delay when you start a game, improving audio-visual sync.