[LG TV] How to Fix Echoing or Out-of-Sync Sound When Using TV Speakers and External Speakers Together

When the TV’s built-in speakers and an external speaker (such as a soundbar) play audio at the same time, you may hear an echoing sound.
This is typically caused by a slight audio delay (latency) because the TV and the soundbar process digital signals at different speeds.
To resolve this issue, change [Digital Sound Output] to [PCM], or use only one speaker output. If you are using a soundbar, you can also correct the audio delay by adjusting [AV Sync].

Why is the sound echoing or out of sync?

• Digital Signal Processing Delay: When the audio output is set to [Auto], a slight delay may occur while the device processes the digital signal. This can cause the two outputs to overlap, creating an echo effect.
• Simultaneous Output (Echo): When [TV Speaker + External Speaker] is enabled, the sound may echo due to the distance between the speakers or differences in speaker performance.

How Do I Fix Echoing or Out-of-Sync Sound?

How to change [Digital Sound Output] to [PCM]

Setting [Digital Sound Output] to [PCM] sends the audio signal without additional compression, which reduces processing delay and helps prevent echoing.

➔ Changing [Digital Sound Output] to [PCM] on 2025 and later TVs (webOS 25 or later)

1. 1. Press the [Settings] button on the remote, then select [All Settings] in the top-left corner of the TV screen.
2. 2. Select [Sound], then select [Advanced Settings].
3. 3. Select [Digital Sound Output] and set it to [PCM].

Use Only One Speaker Output

Instead of using simultaneous output, select either the TV speakers or the external speaker. Using only one output helps prevent echoing.

➔ Changing the output speaker on 2025 and later TVs (webOS 25 or later)

1. 1. Press the [Settings] button on the remote and select [All Settings] in the top-left corner of the TV screen.
2. 2. Select [Sound], then select [Sound Out].
3. 3. Select your desired output speaker.

Adjust [AV Sync] on the Soundbar

If you are using a soundbar, adjust AV Sync to better match the audio with the on-screen video (lip sync).

• Press the [AV Sync] button on the soundbar remote.
• Check the soundbar display, then press the Left/Right arrow buttons to adjust the delay.
• If you’re using an LG soundbar, you may be able to adjust the setting more easily using a supported smartphone app. Check your user manual for supported apps.

※ Note: Steps and feature availability may vary by model. Refer to your product’s user manual for details.

Move left or right to check the contents.

This guide was created for all models, so the images or content may be different from your product.