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How to Adjust Sync



When synchronizing of picture and sound on TV screen does not match (lips moving after words spoken), the viewer can directly adjust the sound sync. User can tweak video’s sync and sound output (TV speaker or SPDIF) by adjusting the Audio Video Synchronization.

There are still a lot of content material out there such as infomercials and old TV advertisements that never got updated with any sound delay to prevent asynchronous issues on televisions displaying much greater resolution than the days of analog broadcast TV.





With the venue of Digital TV High Definition broadcast, stations soon realized they had to

compensate by holding back audio portion matching video signal. Reason being there is

tremendously more video information to be processed in digital than there was in analog

especially since soundtracks remained virtually intact.


That being said, broadcasters managed to incorporate delays in the audio signal so that by

the time the picture was being processed on screen the correct audio time signature would

match lip movement on screen perfectly.


THERE ARE STILL OLDER ADVERTISEMENTS for which atrocious lip sync issue is very

noticeable and difficult to watch.


PLEASE DO NOT AJUST THE AV SYNC for those limited incidents as it will throw off

everything else that was corrected which is the majority of current viewing material.


Only adjust AV SYNC if absolutely everything viewed across all sources connected to the

television experiences exact same deficiency.



AV Sync Adjustment

Adjusting A V sync 

Adjusts the synchronization of the sound from the operational speaker.

The closer to >, the slower the audio output (greater delay).

If you select Bypass, TV will output the broadcast signal or the soundtrack from the external peripheral device without any audio delay. The audio signal may be output before the video because of the time the TV takes to process much greater resolution video input.

HDMI Input Audio Format

HDMI input audio formatting 

You can set the audio format for each HDMI input port. When the voice delivered through HDMI does not appear synchronized, set the input audio format to PCM.



TV Speaker


   - [Vary with the model] Adjust sync of sound that is outputted from TV’s internal speaker. Speed up sound output when moving cursor towards minus sign (-), delay sound output when moving towards plus sign (+).



External Speaker


  -  Control sound sync from external speakers such as LG Home Theatre System, headphone or Surround Sound System connected to optical digital audio output terminal. Speed up sound output when moving cursor towards minus sign (-), delay sound output when moving towards plus sign (+).





-  Matches video signal on screen and sound from external audio device to perfect synchronism without any video or audio delay. Again, depending on how long it takes to produce the image on screen the audio signal may jump ahead by a fraction of second and create this very awkward viewing experience.




[In case of Video lagging]


In Settings Menu -> Sound -> Additional  Settings -> AV Sync Adjustment, implement Audio Delay to control AV Sync (range is about 300ms)

[In case of Audio lagging]

Most field environments (depending on various connections, settings risk causing audio delay)


HDMI 2-depth connection  

Audio process time loss can be minimized by directly connecting the audio input device (Blu-ray player, set top box, gaming console, etc.) to the audio output device.

In the television’s settings menu, set HDMI ARC -> Digital Sound Out: Pass Through.

Total audio processing time can be reduced. If a home theater system is connected to your TV with an optical cable, there may be an audio delay that requires a manual adjustment on the home theater system. There may even be a setting on your TV that's causing the issue.

Peripheral device issue

Note: If the TV is connected to a sound bar or home theater system with an HDMI or optical cable, the sound may be delayed due to the audio processing delays in the sound bar or home theater system. In this case, there is no issue with the TV speakers.

Change Device Audio Output to PCM:

    Step 1. Set PCM in the Device’s Setting Menu (e.g. STB, Xbox, etc.)

Step 2. Change TV menu if the device settings cannot be changed:

Settings Menu -> Sound -> Additional Settings -> HDMI Input Audio Format

Change format to PCM

Audio process time loss can be minimized since the decoding processing has been changed to a quick mode.


Another suggestion is to keep the setup simple and have the Audio Video Receiver or Sound Bar take the role of the entertainment hub instead of the television. To avoid any further aggravation, make sure the external audio equipment’s HDMI output is connected to any HDMI port at the rear of the television at the exception of the ARC port.

The Audio Return Channel (ARC) is designed to get used when all audio video sources are hooked up to the TV for the screen to display the picture while the HDMI ARC input port gets to alter direction sending the audio signal to the external audio device.

If the entertainment hub gets shifted to the audio video receiver or sound bar, there is no point incorporating ARC function in the equation. Instead, every other audio video source such as Internet streaming and/or USB video playability can get the sound to the audio video receiver or sound bar via the Optical Audio Output connection.



On legacy models, AV Sync can be adjusted so the audio from the person speaking on the TV matches their lip movement.


1. Press the Smart button Remote controller Home button on the remote controller.

    Select Settings > SOUND then press WHEEL or ENTER.


2. Select the AV Sync Adjust option and press WHEEL or ENTER.


3. Choose ON if there is a sync issue.

    Adjust the External Speaker slider to the left to delay sound, or the right to delay video.


On-screen audio video syncronization scale


4. If the problem persists, refer to the sections on resolving lip sync issues on external devices.

Should the issue persist further to have updated to latest software version, please contact LG Call Centre at 1.888.542.2623 and formulate your predicament with as much detail as deemed possible so that we may alert software engineers to have them resolve the issue as promptly as possible.

Your patience and comprehension in this matter are greatly appreciated,


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