Question Audio / Video Sync issue with ARC

Pulsar

Well-known Member
Hi all,

I am having difficulty in synchronising the audio and video (lip sync) in my system when using Apps on the TV (Netflix for example) and HDMI ARC to send audio to the AV amp.

Contrary to the usual issue of needing to delay audio to allow for picture processing, I seem to have a situation where I would need to either delay picture (not possible) or advance audio (again, not possible) in order to achieve synchronisation.

I can't believe that I am the 1st person to have this issue as my setup is quite typical in terms of components (LG C8 OLED, Denon X4500H amp).

I have tried both the LG TV and the Denon lip sync features but they only seem to make matters worse as they add more delay to the audio.

Can anyone offer any advice please?

Thanks

Rob
 

dante01

Distinguished Member
I'd suggest the issue is with the TV because the AV receiver isn't handling the video and it is very unlikely that the AV receiver's processing of the audio would result in a delay to that audio that you'd perceive as a lip sync issue. It isn't impoissible that your receiver has a fault, but you'd expect such a fault to be more widely reported. The fact that neither your TV or receiver appear to have inherent and or widespread issues similar to yours means that one of them may have a fault specific to the unit you have? As you say, there's no adjustments you can make to rectify the issue you are experiencing so I can only suggest that you contact Denon and LG and relate the issue you are having to them. THey will both more than likely blame the other, but you can only try.


The only advice LG five relating to you issue is as follows:
[In case of Audio lagging]

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


Basically meaning that it is very unusual to experience this so there's no facility ordinarilly included to rectify it. It would be up to you to route the audio in a manner that is unlikely to cause the audio to be delayed, but this is obviously not a possibilty given the fact that you want to use the AV receiver to portray that audio. THey are only giving you the option of not outputting that audio and using the TV's speakers in order to try rectify the ussue.


However, they also suggest this:
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.

If you've currently got this setting set to AUTO then maybe try it set to PASS THROUGH instead?

The only other thing they suggest is setting the output to PCM, but this will result in you only getting 2 channel PCM as opposed to multichannel formatted audio.


I'm assuming that your TV's firmware is fully up to date? If not then I'd suggest you update it to the most current firmware version. I'd also suggest you ensure all the apps are up to date as well.



There's also a long standing thread relating to the C8 and lip synce issues:

The issue being discussed is however one with an inherant problem with the audio being ahead of the video which I believe LG have since addressed with a firmware revision in association with all of their 2017 models? This wouldn;t be the same issue as you appear to be experiencing though.
 
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gibbsy

Moderator
It sometimes happens with my Panasonic. Turning off the TV for a few second often forces a new handshake and the problem is resolved. This happens with Netflix and Prime. I use a Denon amp.
 

getcarter

Novice Member
Hi there, found this thread and wondered if Pulsar had resolved this, as I have the same issue.
I used to check what was going on - and the audio is behind by about 400ms.

Weirdly I get the same issue on 2 different setups - I mention Youtube as used that app to do the test:
#1. Using YouTube app (or netflix etc) on the Panasonic TV, playing sound via ARC to Yamaha RX-A880.
#2. YouTube on PS4, connected HDMI into Yamaha and then from there HDMI into TV.

I have switched off the optional audio delay on the Yamaha - so am completely bemused on what could be causing this, especially from 2 different scenarios- especially as #2 isnt getting sound via ARC. All the firmware is up to date.
 

Pulsar

Well-known Member
Hi

I have switched TVs to an LG CX OLED since starting this thread. I’m not sure that the issue is fully resolved to be honest, but it’s good enough for me to not worry about it.

I think your 400ms figure is way beyond anything I experienced - I’d guess that I was in the 50-100ms range.

when dealing with ARC, it’s odd to me that you can’t choose to delay the image to compensate for inherent audio delay. Doesn’t seem like a big thing considering how advanced the processing is in these sets. Perhaps it’s to encourage the use of laggy video processing? :D
 

Pulsar

Well-known Member
@getcarter

I just tried this test video on my CX and found that the audio was actually around 100ms ahead in Filmmaker mode and around 50ms ahead in Game mode. I applied ‘25’ to the audio delay setting in the eARC settings and now Game mode is spot on.

I used the slow motion video on my phone to capture the the before and after measurements.

Thank you so much for sharing that video link.
 

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