Audio Lag on 4k with xbox

[Chief Wiggum]

Hi All,

I'm not sure of anyone else has run into this (I'm probably missing something obvious!)

I replaced an aging Samsung LCD with a Sony Bravia 55x90C yesterday and I've got it connected as follows:
Xbox One S > TV (HDMI2) > Optical to Sonos sound bar

Now when in Apps like Amazon prime or watching a Blu-ray the lipsync is out massively from the xbox (audio is delayed). When I took the Sonos out of the equation and went back to the TV it was better, then I swapped out the HDMI cable between the xbox to the TV and that improved things further. However returning the optical out to the Sonos resulted in massive audio lag again. I can cure it by routing the optical directly from the xbox to the sonos, so it looks like the TV is adding some overhead (or is slowing the picture down?).

Has anyone come across this before and how did you solve it? It's driving me mad!

Thanks

 

[Chief Wiggum]

Thanks I'll give game mode a try, but the audio is behind the picture, so adding delay to the audio will only make it worse. I.e. Lips start moving, then you get the voice. It's like watching a dubbed film.

 

[Chief Wiggum]

ok, so I've been doing a bit more testing (must to the annoyance of my good lady), but I've narrowed it down - the delay seems to be coming from the xbox itself when it's doing the Dolby 5.1 / output both via optical and HDMI. If I turn it to Stereo (uncompressed) then everything is matched up. However that rather defeats the point of having a 5.1 soundbar system (arrghhh)

Edit - just checked the Sonos and that says that the input is 5.1 - is the TV upmixing?!