Unable to use Dolby Digital audio - live and downloaded have different lip sync errors

[Pilotjames]

I appreciate that people are always having audio issues when connecting to various AV equipment but my current problem appears to be completely within Sky's domain.

When selecting Dolby Digital or Dolby Digial plus audio outputs and then going through the Sky "Set your self up for UHD and Surround" video turorials you eventually get to the Sky Test cards which include surround speaker positions and a reallly helpful lipsynce timing section to allow you to set up the A/V sync.  

Nailed it.  Full surround with perfect lipsync.

BUT!!,

If you switch back to live TV the sync is all over the place.  Go back to the tutorial video, everything spot on.

Watch some recorded content, forget it.  Audio all over the shop again.

Watch downloaded content ... all is good in the world.

So appear to have a choice, watch content in stereo using PCM output and everything will be fine or, only watch downloaded content for ever and get the surround sound.

This all happens with in the Sky Q box.  

Firstly, please tell me that I'm not the only one.

Secondly, if you found a fix such that you can have the best of the best for all content types, please share your secrets.

For reference, I have a SkyQ UHD STB, plugged in to HDMI1 on an LG C4 OLED and an LG USC9S soundbar connected using eARC , with sub and wireless surround speakers.

TV is set to Passthrough on the audio.

Motion smoothing is turned off in the Clarity menu.

Any input/suggestions welcome as I'm hugely disappointed in the Sky UHD experience so far.

Thanks

[PandJ2020]

I couldn't get correct sync via my LG OLED.  It seems the LG's ARC impacted the sync.

Now, the Q box is connected to my Amp and I only use ARC for TV apps back to the Amp.

[BenJoBanjo]

@Pilotjames 

Make sure you use a certified HDMI 2.1 cable for maximum bandwidth and speed between the eARC ports of the TV and soundbar. 

eARC as opposed to ARC carries more data at greater speed and has automatic lip sync correction when set up correctly. 

If you still can't get decent sync with a new cable then either connecting the Q box directly to the other HDMI input on the soundbar should help, or use an optical connection between the TV and soundbar instead. This will still give you 5.1 audio but won't give you Atmos. 

[Pilotjames]

Thanks.  All the cables are either Sky supplied or new 2.1 cables.  

The soundbar has it's eARC connection via 2.1 cable.

My problem is not that the audio is always out one way or the other, but that the audio changes depending on what the Sky Q box is playing.

I'll try reconfiguring such that the Sky box goes to the sound bar first then use the link to the TV.  While I could go optical, although that makes the source selection more complex for the family, I don't feel I should miss out on ATMOS because the Sky Box won't play with the TV/Soundbar combo, deliberately selected as a matching pair to try to avoid this sort of messing about.

Thanks for your comments though.

[Pilotjames]

I've used, what LG claim is eARC between the LG TV and the LG Soundbar.  

It's all deeply frustrating being forced to watch Sky Movies or the big dramas on Sky Atlantic in muddy stereo because the devices don't get along.

Thanks

[Chodley]

Weird. eARC should automatically offset the audio based on inage processing time

have you tried putting the LG into as non-intrusive a video mode as possible?

I have to say I go via my (Yamaha) amp for most sources and as above, also only use eARC for TV apps.

[Pilotjames]

Audio is on pass through and the video has motion smoothing turned off. 

[Pilotjames]

My issue is difference between live and recordings vs downloaded VOD

that's  what I can't get my head round. 

[Chodley]

Same res?

[Pilotjames]

Live is HD,  Recordings are HD, VOD is a mix of UHD HDR and HD SDR.