When mouth movements and sound do not line up, the issue is usually processing delay. Soundbars, receivers, Bluetooth gear, apps, and even the TV’s own audio engine can add milliseconds of delay after the picture has already rendered.
These steps apply to smart TVs with built-in speakers, soundbars, AV receivers, cable boxes, streaming devices, and game consoles.
Does this affect you?
Use this if voices arrive ahead of or behind the picture, especially when a soundbar or home theater receiver is connected. This is rarely a sign that the TV or soundbar is defective.
Use the TV’s AV sync setting
- Open your TV Settings.
- Go to Sound, Expert Settings, Advanced Audio Settings, or AV Sync Adjustment.
- On Samsung, look under Sound > Expert Settings.
- On LG, look for Sound Settings > AV Sync Adjustment.
- On other brands, search for Audio Sync, Audio Delay, or Lip Sync.
- Adjust the value in small steps while watching a scene with clear speech.
- Stop when speech naturally matches mouth movement.
There is no universal correct number. Your best setting depends on the TV, the source device, and the audio hardware. Some TVs save this per input, so check again if HDMI 1 is fixed but HDMI 2 is not.
Adjust the soundbar or receiver
If the TV’s setting does not go far enough, the delay may be coming from the audio device itself.
- Check the soundbar or receiver remote, app, or on-screen menu for Audio Delay, Lip Sync, or AV Sync.
- Try a simpler sound mode if Movie, Surround, Dialogue, or Night mode adds heavy processing.
- Use HDMI ARC or eARC instead of optical if both devices support it.
- Update the soundbar or receiver firmware from its companion app if available.
ARC and eARC usually handle timing more consistently than a setup where video travels over HDMI while audio travels separately over optical.
Check apps, boxes, and HDMI ports
If sync is wrong in one app but fine everywhere else, update or reinstall that app. Streaming apps can buffer audio and video differently.
If you use a cable or satellite box, check that box’s audio output and delay settings. Some boxes add processing before the signal reaches the TV or soundbar.
Rarely, one HDMI ARC or eARC port behaves differently from another supported port. If your TV has multiple compatible ports, test the alternate port before assuming hardware failure.
Why lip sync settings exist
Modern TVs and audio devices apply noise reduction, virtual surround, dialogue enhancement, decoding, and other processing. Those steps take time. Lip sync controls compensate for that processing gap, so needing to adjust them is normal and expected.
Sources
- Dolby – Understanding audio-video sync lip sync issues (2024)
- Samsung Support – Adjust audio delay lip sync on your TV (2025)
- LG Support – Sync audio and video with AV Sync settings (2025)