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Discussion Starter · #1 ·
I've recently had two new model DLP projectors in the system and both exhibited lip-sych issues.


One sporadically, one with problems on both composite and component constantly.


I first saw lip synch on the Sharp 9000 a while ago and figured by now the problem would be fixed on all machines.


By way of identifying the problem, I then used the Zinwell Brite-View scaler on this projector and the lip-synch was gone immediately. So the lip-synch problem is on board and ongoing.


Is anyone else seeing/experiencing these ongoing lip synch issues on new projectors?


And what's the fix?


Max Christoffersen
www.audioenz.co.nz
 

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Discussion Starter · #3 ·
The video lags behind the dialogue.


It varies from mere milliseconds (but visible nonetheless) to perhaps as much as a second (which on screen is a major delay).


The issue appears to be very flaky implementation of the video scaling chips - but it's been documented for a while and I'm checking to see if it is particular brands, models or types of on-board processing.


As I say, the outboard Zinwell fixed it immediately and normal transmission was resumed.



Max Christoffersen
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Discussion Starter · #5 ·
Which would be an adequate, if costly solution if it worked.


Which it won't. Because the synching varies.


It's not consistent and slows down and speeds up, so what ever set delay parameter you use will be perfectly synched for only part of the time.


It would be easier to simply fix the problem at the source.


Max Christoffersen
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Ah...interesting. so it varies, arbitrarily over time. Then of course, you'd be right...it need to be fixed at the source.


Would be a good help if one can document which scaling chips do this, and in which PJs it appear.


thanks, has been an education for me. Cheers.
 

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I've had lip-synch problems with the Marantz VP-12S2 from time to time, but it was always with a digital satellite source, never with DVD, and it was only certain programs. This tells me it's a problem with the source. It's very annoying when it happens (I had one instance yesterday that made me switch channels), but I don't think you can do much about it. Surround processor/preamps like the Anthem AVM-20 have provisions for delaying the sound (which is what you want), but by the time you have this dialed in the problem may be gone, and then you have to remember to restore the default setting, or else you'll be introducting a delay for sources that don't need it.


Bob
 

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In my experience, it is usually the player, set-top box or video broadcaster rather than the projector that causes lip sync problems. We have seen it on multiple HDTV broadcasts here in the Phoenix area, and it's a combination of set-top box and broadcaster issues. I see it with DVDs on my projector (Studio Experience) with an HTPC, but if I switch from TheaterTek to PowerDVD the sync problems disappear. TT seems to have problems with video-based materials, as I have sync problems with many music DVDs, and recently with the incorrectly flagged Monty Python Meaning of Life CD.


I have tried many things to "correct" TT, as I'd prefer to use this player, but even using all the recommended drivers, it still pops up. I just gave up and now switch to PowerDVD when I encounter lip sync delays.
 

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I have not noticed any with the infocus 7200.

As Darrel has said it usually is the source (STB or dvd player). I have read that it could also be the internal scaler of the PJ.
 

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Discussion Starter · #11 ·
It is the internal scaler.


By eliminating the on board scaler on the two machines and using an external scaler I eliminated the problem immediately. There may be other contribuitors, but if it is the source then it should be consistently doing it on other display devices - it's not.


I have no lip synch problems from any other source or any other scaler other than those on board digital projection.


By the process of elimination, right now, I'm focusing on the display device scaler. But is there a fix for this?


Did the Sharp 10000 have the same lip-synch problem as the 9000?


And how is it that an entry level external scaler can fix the problem when an on-board one can't?


Was there ever a software fix offered for this problem?


Max Christoffersen
www.audioenz.co.nz
 

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Sorry Max, I can't help you on that one. Maybe if you do a search on sharp 9000 or lip sync, as I remember reading about it some time ago or some 9000 owner can tell you.
 

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I have repeatedly noticed lip-sync problems with DTS soundtracks (Sanyo PLV70/Panasonic RP82). These seem to disappear when I switch to dolby digital 5.1. I have this problem with many of the DVDs in my collection. Very irritating.
 

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I have the same combination (PLV-70 and RP-82) and do not get any lip sync problems with DTS. I assume you are using the digital audio out from the RP-82. Perhaps your sync problem is due to the DTS decoder in your receiver?
 

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I have no idea if its the receiver (Denon 3802) or the scaling issues mentioned in the above posts. I suppose If I had a TV I could hook it up and see if that corrected it. Might be worth renting one just to find out for sure.
 

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My sense is that this is a SOURCE problem not a PJ problem. It is well noted with certain audio units. Can go away with tust changing the audio unit. Some HD boxes a re worse. In fact Zenith/LG just updated the firmware software to fix a problem in decodong the audio bitstream. I do not believe it is a video processing problem at all. There are many threads on lip sync isues in the pre/pro forums and set top forums.

Have fun

Paul
 

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I have a significant lip synch problem with many DVDs but only with DVI. When I use component video, there is no lip synch problem. I'm using a Dwin TV3 with a Samsung 931 DVD player. I dont' have any other DVI sources to check but I'm assuming that the problem lies in the DVD player and not the projector. I last heard from Samsung tech support over a week ago. They are "looking into the situation". I'm waiting for the firmware update for the Sammie from my dealer but I really don't know if this will fix the problem. Very frustrating.

Larry
 
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