Lip Sync Issues - LG C1 and Yamaha RX-V6A

soundinthecity

Novice Member
Good morning, I have set up a new home entertainment system and the audio and video is not syncing well. It’s not egregious but I can definitely tell that the video/sound is a few milliseconds off. I changed the Lipsync setting on the Yamaha to 1ms which helps a little, but doesn’t fully solve the problem.

Here’s the gear that I’m using:
  • TV - LG C1
  • AV Receiver - Yamaha RX-V6A
  • HDMI cables - Monoprice 4K Premium High speed
  • Sources - Apple TV 4K or Xfinity Cable Box
And here are some photos of my current settings:

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IMG_2410.jpeg
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I can also send photos of the sound settings on either the Apple TV or Xfinity box if that’s helpful.

Are there additional settings I can try to better sync the video/sound? Any suggests are much appreciated!

Thank you!
 

Mark.Yudkin

Distinguished Member
Unfortunately, many TVs just return some fixed near value, not the exact delay caused by their processing, when configuring the automatic lip sync. In such cases, all you can do is manually alter the lipsync delay on the AVR, which is what you have done. If the value you've set isn't perfect, tweak until it is. You could also consider using the ARC (eARC) settings.

The 5.4 feet difference between the left and right channels indicates a rather off-centre seating. That itself amounts to 5ms difference between the speakers. Since the centre's distance is almost as much as the R speaker's, this would also imply that the centre is very much to the right. Whilst this doesn't explain the lipsync issues, it does imply a very strange and highly imbalanced front sound stage.

(I am amazed you can tell a 1ms lipsync difference.)
 

soundinthecity

Novice Member
Unfortunately, many TVs just return some fixed near value, not the exact delay caused by their processing, when configuring the automatic lip sync. In such cases, all you can do is manually alter the lipsync delay on the AVR, which is what you have done. If the value you've set isn't perfect, tweak until it is. You could also consider using the ARC (eARC) settings.

The 5.4 feet difference between the left and right channels indicates a rather off-centre seating. That itself amounts to 5ms difference between the speakers. Since the centre's distance is almost as much as the R speaker's, this would also imply that the centre is very much to the right. Whilst this doesn't explain the lipsync issues, it does imply a very strange and highly imbalanced front sound stage.

(I am amazed you can tell a 1ms lipsync difference.)
Thank you so much for this insight @Mark.Yudkin. If you don't mind, I have two follow-up questions:

1. The speaker distance was set when I tried to use the Yamaha YPAO. In reality, the center speaker is about 11' to the couch and each side speaker is roughly 12' to the same point int he couch.

Should I just manually change these to make it more even, or set it to something more standard?

2. Should I enable eArc on just the LG TV or on each device hooked up to it?

Thanks so much!
 

Mark.Yudkin

Distinguished Member
1. If YPAO messed up this badly, I'd suggest rerunning it carefully in a quiet environment. That ought to correct the distance, but also other issues you may have but not have realized. At the moment, you have an additional 5ms delay from the RIGHT and CENTRE channels, as the real LEFT distance is 5 foot less than set up.

2. My answer is a resounding "enable eArc on the TV and the AVR". The other devices are not involved in eARC. Please note though that there are others here who will be quite vociferous to say No. I would only consider disabling eARC if enabling it causes additional issues.
 

soundinthecity

Novice Member
I updated the distance on the channels and that made a HUGE improvement.

I'll definitely try the eARC setting. Doing a quick search though, it looks like I may need to upgrade my HDMI cables to be 2.1 compliant, no in order for eARC to work correctly, no?
 

Mark.Yudkin

Distinguished Member
Doing a quick search though, it looks like I may need to upgrade my HDMI cables to be 2.1 compliant, no in order for eARC to work correctly, no?
eARC does not need HDMI 2.1 with 48 Gbps cabling ("ultra high speed cables") and you do not need to upgrade your cables if they are work at all at 4K.

You only need HDMI 2.1 with 48 Gbps cables if you have HDMI 2.1 devices throughout. Your TV is an HDMI 2.0 device.
 

cns

Standard Member
The subwoofer distance would usually also be significantly greater than the speakers, to account for group delay (extra time to pass though the subs amp). Perhaps rerun ypao instead of manually adding the distances.
 

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