TV sound through a port

Go to Settings —> System —> Port —> Audio Delay and select 75ms.

Check the latency on your DAC and if it isn’t tiny in comparison to the Sonos 75 ms delay a faster one might be an improvement.

I have done this in two places and it works very well, once the delay is set to minimum as suggested, with no lip sync issues at all. Both using the Connect/Connect amp analog line in, but I doubt a Port will be different. I am surprised to read that interposing a DAC to use the digital outs of the TV will by itself add noticeable delay, but do not have much direct experience of that solution.

I have used the stereo audio out jacks on an older LCD TV, wired to line in on Connect and this also allows the TV sound to be piped to other Sonos zones when needed. Except that for stable play, that needed all the Sonos units to be ethernet wired to the base router. But no lip sync issues of any kind.

On a latter day model TV in the bedroom. that lacks the audio out jacks, I had wired the headphone jack of the TV - fortunately, that is there - to a Connect Amp, and that too worked fine. I have replaced that now with powered speakers because I do not need a Sonos zone there, but the Connect Amp worked with no synch issues as well. One advantage of the headphone jack is that because it is volume level controlled, only the Firestick remote is needed to change sound levels of the TV obtained from the external speaker pair.

As an aside - a couple of decades ago I discovered that all my TV sound needs were met by a pair of HIFi quality external speaker pair and if I wanted surround for the rare movie, the multiplex was a better way to get it. I have had no reason to change that thinking till now, and I doubt now that I ever will.

I think people are wired differently as to noticing lip sync problems. I would definitely notice 75ms delay.

It depends on the TV service. Some are inherently awful at sync. UK ones are generally good, especially the major broadcasters. 75ms would be noticeable for speech; not so much for live music, where the Meridians could be of obvious benefit.

Yes, I also notice. When lip sync totally out of your control, eg someone else's TV etc, or a live broadcast interview from sports event etc, there is a possible solution, and works for me:

Don’t look at the lips, concentrate on the eyes.

In my area the movie channels tend to have the best sync. I recently encountered a cable box with horrible sync. Fortunately, adding about 150ms of audio delay helped.

I refuse to accept that I am wired differently; or if so, everyone that has watched my set up is as well. Not one has noticed anything off, be it for movies or for music videos with close ups of strumming/drumming.

Obviously, I am not complaining or interested in investigating this outcome.

Per OP first post, he too has not said anything of suffering any such effect in his old house.

It seems like it could be the TV as well, really anything in the chain from source to sink.  15 ms positive or negative won’t be noticed alone, but they will add up.

I’m sure that you and I are wired differently and I’m not claiming that either of us is ‘standard’. I can be rather brutal in a “my dog is better than your dog” HiFi showdown because, in my opinion, all of the dogs might have fleas.

The goal is to learn what is “best” for you and go with it. Don’t be too concerned if your idea of “best” clashes with another. Hopefully, you don’t live with that person.