Audio delay between your LG OLED TV and soundbar creates annoying lip sync issues where voices don't match mouth movements. This happens because your TV and soundbar process audio at different speeds, creating a timing mismatch.
Quick Answer
- Go to Settings → Sound → Additional Settings → AV Sync Adjustment and move slider to -5 or +5
- Enable Settings → Sound → Sound Out → HDMI ARC, then turn on eARC Support
- Change Settings → Sound → Additional Settings → Digital Sound Out to Pass Through
- Update TV firmware to latest version (C3 needs 03.33.05+ for Dolby Vision fix)
Symptoms
- Voices arrive before or after actors' lip movements
- Audio delay most noticeable during dialogue scenes
- Sync issues vary between Netflix, YouTube, and other streaming apps
- Problem worse with Dolby Atmos or surround sound content
- External devices (Apple TV, PlayStation) have different delay than built-in apps
Quick Checks
- Test multiple apps - Netflix vs YouTube vs built-in media player
- Try different HDMI cables if using ARC/eARC connection
- Check if delay happens with TV speakers (switch temporarily)
- Note if problem is consistent or intermittent during viewing
Step-by-Step Fix
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Access audio sync settings: Press Settings on remote → Sound → Additional Settings → AV Sync Adjustment
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Adjust sync slider: Move slider left (negative values) if audio comes first, right (positive values) if video leads. Try -5 to start.
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Enable eARC properly: Go to Settings → Sound → Sound Out → select HDMI ARC → scroll down and set eARC Support to ON
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Change audio processing: Settings → Sound → Additional Settings → Digital Sound Out → select Pass Through (not Auto or PCM)
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Update firmware: Settings → General → About This TV → Check for Updates. C3 users need version 03.33.05 or later.
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Enable LG Sound Sync (LG soundbars only): Settings → Sound → Sound Out → LG Sound Sync → ON
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Test with different content: Play dialogue-heavy scenes from Netflix, YouTube, and USB media to verify fix
If Audio Delay Still Occurs
Check your soundbar's own sync settings. Many soundbars have dedicated lip sync adjustment in their menus or apps.
Try different HDMI ports. Some LG TVs handle eARC better on specific HDMI inputs (usually HDMI 2).
Reset sound settings completely: Settings → Sound → Reset to Initial Settings, then redo the steps above.
For persistent WebOS app delays, adjust AV Sync per input: switch to Netflix, adjust sync, then switch to YouTube and adjust separately.
Consider a high-speed HDMI 2.1 cable if using eARC. Bandwidth limitations can cause processing delays.
FAQ
Why does my LG C3 have worse lip sync with Dolby Vision content? Earlier firmware versions (before 03.33.05) had a bug causing sync drift during Dolby Vision playback. Update your firmware to fix this specific issue.
Should I use Auto or Pass Through for Digital Sound Out? Use Pass Through. Auto mode re-encodes audio signals, adding processing delay. Pass Through sends original audio directly to your soundbar.
Why do Netflix and YouTube have different sync timing? Different apps process audio independently. WebOS handles each streaming service's audio pipeline separately, creating unique delay characteristics. Adjust AV Sync for each input source.
Does eARC really help with lip sync issues? Yes. eARC provides higher bandwidth and better timing synchronization than standard ARC. Enable it if both your TV and soundbar support eARC connectivity.