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Lip Sync Issues with TV & Sound Bar


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Old 04-03-2016, 08:13
ichilton
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Hi,

I've got a Samsung UE48JU6400 48" 4K TV and a Samsung HW-H550 sound bar. The sound bar is connected by both the Samsung wireless "TV Sound Connect" and with ARC via a HDMI cable (I could also do optical but the optical port on the sound bar has something else connected at the moment).

Input wise I use Sky, AppleTV (4th Gen) and Amazon FireTV (the original).

Some things we watch are fine, but other times the sound is annoyingly out-of-sync with the picture, so you see when people are speaking that their lips don't match up with the picture.

Both the TV and sound bar have "audio delay" settings, which i've tried to experiment with, but haven't been able to get it right - I probably need to spend more time experimenting....though it also seems to change between different programmes.

Anyone have any tips on settings to improve/solve this?

I've then just this week bought a Panasonic VIERA TX-48CX350B (48" 4K also) for another room as it was on offer. I've paired this with a Bose Solo 5 sound bar. The sound bar doesn't seem to have an audio delay feature, and altough the TV has a number of options for sound, it doesn't seem to have an audio delay feature that I can find. Doing initial tests with the AppleTV & FireTV, I was pleased to see that it didn't have the same issue with lip sync. However, last night I was testing it again and when I clicked on some old films (like Top Gun) through Now TV on the AppleTV it was way out.

Is there a fix to this? - do I need to return the TV if it doesn't have a delay setting? - or does it and i'm just not seeing it?

Thanks!

Ian
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Old 04-03-2016, 11:08
mred2000
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I've a Philips TV and soundbar and found that going via ARC 'only' from TV to soundbar is awful when it comes to sync issues - the sound always comes after the picture and, as all audio sync settings on all the kit I have just delay sound even further, there's no easy way of dealing with it.

So, even though ARC is supposedly infallible, I've found I've had to input my SKY box directly into the soundbar via optical cable and my games consoles directly into the soundbar via HDMI... anything going through the TV first ends up with a delay. In researching the issue I've found many people having this same problem, even with TV/soundbar combos supposedly 100% compatible (same manufacturer, for example...)
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Old 04-03-2016, 11:53
ichilton
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Hi,

Thanks - that's interesting.

I too was wondering if it was the picture behind the sound and hence why increasing the audio delay didn't help.

Thinking about it, I only noticed the problem on the Samsung after connecting the HDMI cable to use ARC. I wonder if having that connected changes something, even if I then use the wireless SoundConnect. I might try disconnecting that.

On the Panasonic+Bose combo it's a bit more of a problem as the sound bar doesn't have a HDMI input.....and the Apple TV doesn't have optical out, so I might be a bit screwed on that front.

I'm pleased with the sound from the Bose - it obviously doesn't have as much bottom end as my Samsung with the separate subwoofer in the lounge but it's nice and compact for the smaller room. Maybe i've bodged though with it's lack of HDMI and things like audio delay option.

Will have to do more experimentation I guess.

Ian
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Old 04-03-2016, 12:09
chrisjr
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The sound should precede the pictures. Processing the audio is far quicker than processing the images. So if there were no delay you should hear a person's words slightly before you see their lips move.

If it is the other way round (ie lips move before you hear the words) then that indicates a problem, especially if the delay time is set to zero. And obviously as you can only delay the audio further you can only make things worse in that scenario.

I would advise you to use only one audio connection. That way you don't end up tweaking, say, the HDMI when using wireless and hence having no effect whatsoever on what you are hearing.

Have a listen to the TV's built in speakers without the soundbar on for a while. Do you get the same delay issue with those? If the audio lags behind the pictures even on the built in speakers then I would suggest the TV is faulty.

And only use the delay on one device. Set one of them (doesn't really matter which) to zero and lock it there and only ever adjust the other. Keeping things as simple as possible is never a bad idea.

Also turn off any and all audio processing options in the TV just in case they are screwing things up. Equally turn off any picture processing options, especially anything that contains the word "dynamic" or "auto" or similar. Very often all they do is make the situation worse. Again keep it simple
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Old 04-03-2016, 19:27
howard h
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If I go to Audio in settings on my telly, (LG), there is an option to sync the speakers with the picture, ans a sliding scale to get it spot on. So when I occasionally have this issue with my soundbar (connected via headphone socket) that cures it.

I would be surprised if any other top TV's didn't also have this feature - so look deep inside the settings function and you might find something!
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Old 04-03-2016, 19:53
mred2000
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If I go to Audio in settings on my telly, (LG), there is an option to sync the speakers with the picture, ans a sliding scale to get it spot on. So when I occasionally have this issue with my soundbar (connected via headphone socket) that cures it.

I would be surprised if any other top TV's didn't also have this feature - so look deep inside the settings function and you might find something!
My TV, SKY box and soundbar all have audio sync tweaking abilities, however they only add to the sound delay so don't help in my situation.
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Old 05-03-2016, 17:24
njohnson
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Lip-sync does change between programs and even DVD's and BluRay discs but one thing to be aware of - especially in forums - is that each of us may differ "significantly" in our recognition of lip-sync error.

One forum member - while trying to help - may say he has no lip-sync error even though he may be viewing the same error that's driving another member crazy.

I should say - more accurately - we differ in our ability to avoid noticing the contradiction of reality lip-sync error confronts us with. Since lip-sync error is impossible (in the real world) evidence suggests we have a defense mechanism - a coping mechanism - of looking away (subconsciously) from out of sync lip movement or perhaps de-focusing on those lips.

A study at Stanford over 20 years ago showed most people don't consciously notice a 43 ms lip-sync error and some of us don't notice even twice that until we are exposed to a large enough error to break through our subconscious avoidance mechanism. Once broken we focus on the lips and our threshold of recognition falls significantly. Some people can even detect less than one ms lip-sync error when they are deliberately focusing on the lips!

That research at Stanford statistically correlated a feeling of "distrust" of the characters and material presented when lip-sync was off even when the viewers did not notice the problem.

The adjectives that report used to describe viewer feelings about the characters (more agitated, less successful, less persuasive, etc.) when lip-sync is off are the same words we often use to describe people who don't make eye contact with us but the evidence suggests it is "the viewer" who isn't making eye contact with the characters while subconsciously trying to avoid the impossibility of "sound before the event that creates the sound."

Although the Stanford research only measured and statistically correlated the negative impact of lip-sync error and did not determine "why" it has this impact it does support the theory viewers are either looking askance physically or deffocusing mentally when the image and sound contract nature.

Also, the fact that almost everyone will "see" lip-sync error they previously ignored when they are asked to focus intently on the lips supports this theory and I would suggest that anyone in forums commenting on their lip-sync error (or especially the lack of it) should first force themselves to focus on the lips to overcome the natural tendency to look askance which masks the problem.

I use a separate digital audio delay and adjust for perfect sync down to the ms when talking heads first appear in each program. The delay I need for perfect sync can vary over 60 ms and sometimes goes below the fixed delay needed to offset my TV's video delay. In those rare cases (delayed audio) I'm using some of my TV's video delay to offset the delayed audio.

My TV's video delay is about 80 ms so when I find perfect lip-sync at 66 ms on my delay I'm actually using 14 ms of my TV's video delay to cancel the arriving audio delay.
But most programs we watch need about 130 ms audio delay so that's 80 to offset my TV's video dealy and another 50 ms to offset additional video delay in the arriving signal.

Of course that will vary depending on where you are and what equipment you have and may even vary from day to day when the same program is re-broadcast.

As ChrisJr said above it is best to turn all audio delays you might have (STB's, TV's, DVD and BluRay players and Av receivers sometimes offer audio delays) off or set to zero (especially turn OFF the HDMI Auto Lip-Sync if you have it) and pick the one that offers the smallest incremental adjustment and is the easiest to change. Unfortunately many of these devices offer huge increments of 5, 10 and even 20 ms so you may not be able to find a spot you feel is "perfect" but you might get close.

If you are interested in the Stanford research do an Internet search for "Effects of Audio-Video Asynchrony on Viewer's Memory, Evaluation of Content and Detection Ability" or go to Wikipedia and look for "Audio to Video Synchronization" where the Stanford research is quoted and the PDF link appears in the footnotes.
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