TV sound through a port

Processing delays in the TV signal pipeline shouldn’t matter, as it ought to have audio and video in sync at the point of final delivery. Some will also compensate for Bluetooth latency. It’s where the audio and video streams diverge outside the control of the TV that problems can arise. 

As a general statement, I agree; we would not be human if that was not the case.

But this is not a wiring case in my opinion, because noticing a difference in seeing when a guitar string is plucked and when the note is heard is the same for all healthy humans. As is established by the fact that it is not just I that does not pick out the delay in this case, but no other family member or guest has till now, even when asked if they do so. To repeat what I said.

And casually saying, as 106rallye has, that wiring is different dismisses considering the possibility that there may be something happening in the TV that is compensating for the Sonos delay. I cannot establish that in the bedroom set up because the headphone jack of the TV that is used cuts out the sound to the TV speakers. But the next time I use the other set up in a balcony, I will see if I can hear any sound echo when the TV sound that is set to zero there, is dialled up. Because I do hear an echo if an Echo device wired direct to an amp is played along side one wired to a Connect and thence to another amp or to other Sonos speakers. Again, those differently wired will still hear that echo, I believe.

Both TVs happen to be Panasonic of 2011 and 2019 vintage.

https://www.city.ac.uk/news-and-events/news/2017/04/are-sight-and-sound-out-of-sync

They team found that there was an average auditory lag of 91ms for the phoneme identification task (based on the famous McGurk effect) and 113ms for word identification, but this varied widely between individuals.

Going back to OP original question, would one of these work? Assuming the 75ms delay was acceptable:

http://www.cypeurope.com/store/store/app/product/AU-1HARC/HDMI-to-Stereo-Audio-2-Phono-ARC-extractor

That will work if the TV has the HDMI ARC socket - not all do. But before trying any other hardware, OP should make sure that he has done what buzz has suggested early on about setting the Port for a minimum delay and see the outcome with the DAC hardware he has in place.

Once he does that, OP set up should be equivalent to what he says worked fine with a Connect at his earlier residence, with no visibly intrusive sync delay referred to for that use case. From what I know of DACs, just interposing one between the digital out and the Port analog inputs should not add any delay; Sonos adds the delay because it is needed to get other Sonos units to sync perfectly when grouped, not because its DAC causes it, per se.

I will probably do my testing of my balcony set up tomorrow, to see if the absence of the lip sync issue is accompanied by a sound echo issue when the TV speakers come on; the source for the TV is a Firestick.

I can’t say that I’ve looked in to it that closely, but it seems logical that a device in the pipeline could get away with being out of sync by 15ms or so without it being viewed as a flaw, as no one notice any sync issues with the device specifally.  In theory, several devices in a chain could compound to cause a noticable issue.

Well I know for a fact that my Sony OLED takes quite … a ... while to process the video. Sync with audio direct from an Apple TV was absolutely hopeless. However audio from the TV itself is of course perfectly in sync with the picture, and that includes its own Bluetooth to headphones. 

That would suggest that if a HomePod is used for the TV sound, as it can be if the latest version of Apple TV is the source, wired for video to the TV and wirelessly to the HomePod, the sound would play ahead of the video? With an echo caused if the TV speakers are then turned up?

I have a suspicion that in my Panasonic LCD, the TV  stereo audio out jacks are putting out sound ahead of that from the TV video/audio, and when those jacks are fed into the Connect, the 75 ms Sonos delay is matching the Panasonic delay to the extent needed for lip-sync to look fine.

If I hear no echo when the TV speakers are turned up in my test, it would mean that this Panasonic delay is very close to 75 ms because it takes less timing differences for echos to be heard than for lip sync issues to be intrusive.

The audio direct from the Apple TV was ahead of the picture. But, like I said, audio and video at the TV’s own outputs should always be in sync (subject to any manual intervention via its settings). A TV can’t second-guess what it’s unaware of, downstream of those outputs. 

Result of the test: when the TV sound is turned up, there is a noticeable and therefore intrusive echo when compared to the sound via Connect fed by the audio out jacks of the TV. 

So, I watched separately for lip sync issues with just the TV sound on, and then just the Connect supplied sound on.  Very carefully, toggling between the two more than once. There was, no surprise, perfect lip sync when just the TV sound was playing. But, as in the past, even careful watching left me unable to find a difference I could see between the lips and the sound.

My conclusion: there is something happening in the TV and its speakers that is causing a delay in the sound as compared to what is being put out by the audio out jacks of the TV. But that delay is not 75 milliseconds but somewhere close enough to that such that the lip sync is not affected. But not as close as is required for there to be no echo, which suggests the elimination of echo effect needs a much higher level of temporal synchronisation of video and audio, compared to what it takes for lip sync issues to disappear.

All I can say is that I am happy for what the TV is doing, because it is making the Connect supplied sound to be close enough to the video it is putting out for there to be no lip sync issues.

Back now to an evening of music videos in the balcony, with video from the Firestick into an HDMI input on the TV and audio via the audio out jacks of the TV to Connect to Yamaha stereo amp that has a speaker pair wired to its speaker terminals, a Yamaha Sub wired to one line out on the amp, and a third speaker wired to the second line out on the amp to get sound good coverage for the entire balcony, all with no visible lip sync issues or any echo! I see no further need for looking this gift horse in the mouth, and all will be well as long as the present Panasonic lives because there is no knowing what will happen if the TV is changed.

Ah, well. Music videos are notorious for poor lip-sync (some of which could of course simply be due to miming). 😕