SKY box + LG OLED + Panasonic 5.1 Home Theatre setup causing lip sync issues via Optical

[TonyTurbo78]

Hi guys.

This one is driving me nuts now. I can not solve this annoying audio out of sync issues when watching TV for a few hours. I've been reading thread after thread on forums of people having exact problems. Tried several things, the only thing that seems to work is just by using HDMI from the Sky box straight to the TV and totally chinning off the home theatre. I've tried adjusting TV settings and also changing the HDMI and Optical sound settings on Sky to "normal" but nothing seems to work.

Any ideas?

The way I had it was Optical Out from Sky box to Optical in on the Panasonic Home Theatre box.

Just a note, back of TV has Optical Out and the back of Panasonic Home Theatre has two Optical In, one of which is marked "STB" the other "TV". What's the best way to connect?

 

[lucid]

The labels on the back of the Panny surround system are just there to make it easier to follow the directions in the manual. They both do the same job; they're both just optical inputs to the surround kit.

Sky's lip sync isn't consistent across all the channels. Some have less of a lag, others have more. The best you can hope for is a reasonable compromise. Next, if you have HDMI Control (HDMI-CEC / VieraLink / BraviaSync / Simplink / Anynet+ / EasyLink etc) enabled and the auto LipSync feature switched on then the HDMI connection from the Sky box to the TV will be trying to override your manual settings. Either switch off CEC completely or disable the auto LipSync feature if that's an option.

There's some other stuff that affects LipSync too. A big one is the TV's picture processing. The more settings you have active for stuff such as contrast enhancement, noise reduction, colour improvement etc then the more individual processes the picture will have to go through. More processing equals more delay.


The optimum settings when you have an Optical connection from the Sky box to a Dolby Digital compatible surround system are as follows: Sky box audio menu - Optical Out = Digital. Delay = 20ms (remember to press Green to store the changed settings). Depending on your package and the channels you watch, this will give your Dolby Digital for those channels that carry the audio in 5.1 For the rest they'll be delivered as Stereo PCM and often with Dolby Surround (DS) encoding. Your sound system should auto detect DD5.1 Where the sound is DS then use the Dolby ProLogic II Movie setting. If you leave the surround kit set on that then it will switch to this automatically where the sound isn't in DD5.1

Switch off HDMI control in the Sky box set up menus. Press green to store the changed setting.

Next, make sure your Panny surround system is set up properly. Read the manual. Get the speaker distances set as close as you can to the real measured distance for each speaker. These distances are a way of setting the system's sound delay to each speaker. This bit is often skipped because getting a tape measure out is too much like hard work, but it really does need doing.

Finally, make the LipSync adjustment via the Panny menu if it has the option. If not, then you can make some course adjustments with the Sky menus.


Routing sound from the TV's Optical out is fine but you'll often forego DD5.1 for any sources connected via HDMI. That means the Panny surround system will be working almost exclusively in Dolby ProLogic II Movie mode. You'll still get surround, but it won't be as pinpoint accurate as DD5.1

 

[TonyTurbo78]

@lucid brilliant info. Excellent read that. Will persevere with it.