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Lip Sync Issues (asynchronous sound)

  • Troubleshooting - Audio
  • Audio Out Of Sync
  • Troubleshooting
  • TVs




Sound Sync (Smart)



Smart  è Setting è Volume è Screen/Sound sync control


When synchronizing of picture and sound on TV screen is not matched, the viewer can directly adjust

the sound sync.


User can adjust video’s sync and sound output (TV speaker or SPDIF) when turning screen/sound

sync control “On.”




Since the introduction of HDTV it is not uncommon to notice very obvious terrible lip synch on screen.

These incidents mostly occur during advertisement breaks. Reason being that HDTV requires more

processing than its predecessor analog broadcast, the audio portion of the signal having remained

virtually the same, now, in HD mode some segments have the voice coming across faster than the

image causing bad lip synch effect.

Most broadcasters and some advertisers quickly adapted by forcing the sound signal segment through

a delay process so that both synchronized picture and sound appear at the same time on screen.


Should this obvious lip sync situation only be noticeable here and there and mostly on some older

advertisements and definitely not always, do not adjust your set. Again, some producers have not yet

fully understood the move to digital TV and therefore haven’t adapted the process of introducing some

delay to their products’ audio track.



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.



For any individual still experiencing asynchronous audio video (lip sync) issues on their 2017 LG Smart TV from hooking up peripheral device to the television and viewing 4K content material, please ensure TV software has been updated to latest version (04.70.07) or greater.

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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