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Discussion Starter · #1 ·
I am wondering if there are others sensitive to these problems and how best to correct them.


edit: Thanks to everyone for their helpful comments. I purchased a receiver with adjustable 0-200 milliseccond delay. An 85 msec audio delay offsets the video delay in my Panasonic TH-42PW5.
 

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radarblip:


AFAIK, the audio delay is caused by 3:2 pull down processing. I have a Pioneer 503 and the manual states that Pure Cinema (their 3:2 pull down) can cause it.


I have a Faroudja NRS, which adds about a 68ms delay. I use the delay feature in my preprocessor to offset it for my middle speaker.
 

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Two frames isn't that bad, about .03 seconds. If you're sitting 10 feet away from the TV, you're getting a .01 sec delay in the audio as the sound is only moving to your ears at 1000 ft/s, that means the net synch delay that you experience at a normal viewing distance is only .02 sec. Do you notice a change in synch from when you're standing right in front of the TV to when you're standing 10 feet away? Probably not.


More likely, they guys that are mixing whatever you're watching are having the same problems as the guys in the article you reference. Your source material probably has a synch problem.

---------------

Subsequent to making this post, I saw Jim's above. He's probably right, it's probably something like the pulldown causing any noticeable video delay.


Are you experiencing the video delay with all sources or just some sources?
 

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I'm not sure it's the 3:2 pulldown per se. Panasonic's use 4-field deinterlacers, which take 4/60ths of a second, or >.06 seconds to assemble the best possible picture. I think they do this whether the source is film or video because the 4-field stuff predates their support of 3:2 IIRC.


Mark
 

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I should add that I have a very noticeable lip synch delay. To my eyes and ears, it seems to be almost a 1/2 sec off, but I realize it's extremely difficult to quantify qualitatively. I haven't had a chance to get my panel mounted to the wall yet. so it's sitting on the ground on the included stand. I have my tv on to use as audio, and it is in comparing the two images that I notice the delay.


FYI the setup is as follows: Denon 1600 DVD player video and audio RCA outs running into the inputs of a Toshiba VHS deck. The tv is connected via coax out from the vcr, since it's an el cheapo tv. Video from DVD to Pio 503cmx is by digital optical cable.


So in the set up there is no processing done by a receiver/pre-amp since there is not one in the chain. The delay must originate from the tv, vcr, dvd player, or plasma.


Thoughts?
 

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Yes, that is what the feature is for video1.
 

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Rogo, if the KD card really does compensate for the lip synch delay, it might have to move to the head of the class as far as card upgrades. I know my pre-amp/processor has timing delay values that you can set, but being that I have both a front projector and the plasma, the values for each might need to be different. And I don't think the pre/pro allows two different store sets of numbers.
 

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radarblip, AFAIK the Key Digital card only works on the Pio 433/503 series and their Elite counterparts. Unfortunately the Panasonics do not have an upgradeble slot at the present. For your situation, playing with the adjustable time delay on the pre/pro might be the ideal solution.
 

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Radarblip,


Great thread and you've cited some good info. I'm going to check out the Tag McLaren.


Rogo, you're on the right track too. You can expect about 75ms delay of video relative to audio on some panels, that's equal to 4.5 fields, and some PDP brands (engineers tell me) are up to twice that time.


Too long a video delay makes for problems in gaming / simulator use. Also in 2-way communication like teleconferencing.
 

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radarblip,


If your A/V receiver doesn't have a delay option (this might be a good excuse to convince the wife it's time to upgrade that A/V receiver), then you might want to look into an audio delay system.


I believe Vigatec produces a unit that allows you to select an audio delay and adjusts it accordingly.
 

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I have not found my Panny plasma to introduce noticeable sync delay. Most of the time the sync looks right on (and I'd notice, being as I examine sync all day in my job as sound effects editor). On most cable channels and DVDs the picture/sound is in sync.


That doesn't mean I haven't seen a lot of picture sync problems - but it's always been the fault of the source. Some cable feeds have a slight delay, so do some DVD titles.


Rich H.
 

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Incidentally, adjustable audio delay is coming to sub-$1000 receivers, like the Denon 3803 for example.


Mark
 

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I have a Panny 50". I don't recall ever seeing any lip-sync issues when watching DVDs (we have a low end non-progressive Sony DVD player at the moment). Nor do I recall seeing any lip-sync problems with our DirectTivo. However, it seems that every pay-per-view we order on DirectTV has a serious lip-sync problem. So much so that it "encouraged" me to upgrade my receiver to a Denon 5803 because it has the audio-delay feature. The last movie we ordered, Road to Perdition, I had to crank the delay up to 200 ms. Not happy about it, but it's a solution that works for us.



Mark
 

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I have to add that I never had a lip-sync issue with the Pioneer 503 using HD, DirecTivo, DVD.


Not saying it's impossible to have one, just that I never did.


Mark
 

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This is off the top of my head, but my Meridian processor provides lipsynch correction and the reason given is that some sources are purposely given a delay such that the correct lip synch is achieved when viewing at (from what I remember) 40 feet away. Of course, if you watching closer, then the lip synch will need adjusting.


-Ian
 

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Anyone who watches Showtime HD with any consistency will be convinced AT TIMES they have a serious lip synch problem. However, when I watch any other channel, including HD channels, this problem does not exist. I would only assume a problem with my equipment exists if the problem persists from channel to channel, source to source.
 

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I'm glad I wasn't imagining the delay on my Panasonic 40" LCD, but my problem may be unsolvable. Besides having the delay with TV, I also get it while playing Xbox. Pushing a button on the controller for what's on the screen, seems to be actually a little late all the time. It seems this forum has ID'ed my problem, but now, do I have any recourse to fix this? I can't slow down my Xbox by 75-200ms can I? Thanks for any advice.


mikeuzdavines
 

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I have had a 42" Panasonic for about a year now and do not notice any lip synch issues. I do not have Showtime HD but all other sources are fine.
 

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I would guess that sync correction will filter down into less expensive A/V receivers because, hell, many things do. But I would also guess that as HD production improves and as deinterlacing becomess less necessary over time (at least complex, multi-field deinterlacing), it might not be so necessary.


At least I can hope.
 
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