Apple TV + LG C8 - What audio delay do you use?

[Engram]

I recently upgraded my setup to an Apple TV 4K, Onkyo 686 and LG C8.

The picture is fantastic, but I'm really struggling to find the correct audio delay for lip sync.

In the past I've used 24 FPS "lip sync test" videos, which I film and then replay in slow motion. The slow motion makes it really easy to see the audio/video offset, and I adjust the receiver accordingly.

With this new setup, the lip sync videos seem to be in sync even at 0ms delay (which is bizarre because the C8 has an input lag of ~50ms).

And when I play actual films the required delay seems to be closer to ~160ms. That's for iTunes Movies (with Dolby Vision), but also HD and UHD played through Infuse. I also feel like the delay changes slightly,
depending on the content.

Some of the things I've tried to try and obtain a consistent delay (with no success) are:

Auto lip sync setting on receiver on/off.
Frame rate match on Apple TV on/off.
Apple TV audio output forced to stereo.

If there's anyone here with a similar setup, what audio delay are you using? And are you getting a consistent delay in iTunes, Infuse, iPlayer, Prime Video, etc?

Edit: Just found this thread that seems to be describing a very similar issue (different receiver)! https://www.avsforum.com/forum/40-o...ync-issues-lg-oled-denon-avr-apple-tv-4k.html

Still curious to hear how you guys are dealing with this issue though.

 

[5punk3monk3y]

The problem I found with the Apple TV is that the audio delay varies from content / which app you are using and also depending on the audio type being output from the Apple TV much like you have discovered. The issue I found was actually on the AVR side between decoding the contents audio and passing through the video.

As Apple TV uses Dolby Digital + for Atmos content and does not support HD audio the solution I used was to plug the Apple TV in to my TV then use ARC back to the AVR, my TV supports DD+ on ARC and passes the Atmos through all lip sync issues have been cured this way round. However Netflix does not report 5.1 / Atmos content on the menu screen and also the AVR sometimes looses the surround when watching Netflix through Apple TV but TBH this doesn't matter as the built in app on the TV works perfectly. my setup is in my sig...

 

[Engram]

Ok, thank you, I'm going to try that next. As we have a very similar model of TV hopefully it will work for me too.

Did you need to set any audio delay for the ARC input on the receiver? (Can you even do that without access to the OSD?)

 

[5punk3monk3y]

Ok, thank you, I'm going to try that next. As we have a very similar model of TV hopefully it will work for me too.

Did you need to set any audio delay for the ARC input on the receiver? (Can you even do that without access to the OSD?)

No, not using the method I adopted, the sound to video to my ears is 1:1, if all goes to plan you will notice it straight away.

 

[Engram]

Ok, fingers crossed! I will report back.

 

[Engram]

I tried this out last night, and it made a big difference: the sync appears to be the same for every type of content now, and it's almost correct with 0ms delay on the receiver.

It still doesn't look quite right though, and it's so close that it's really hard to tell by eye in which direction it's wrong.

My 24 FPS test video indicated the audio was about 1 frame behind (~40ms), which reduced a bit when I enabled the "AV sync bypass" setting in the TVs audio options.

If I'm reading the manual correctly, the TV's AV sync settings allow you to delay the video, which I could use to correct that 1 frame error. I'll continue to fiddle with it tonight.

 

[Engram]

Final update: The TV doesn't allow you to delay the video (despite the manual suggesting it can). I think 0ms delay is actually accurate, but I need to watch more content.