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Audio delay with projector

2076 Views 14 Replies 9 Participants Last post by  Bigfire
Hi, I have a relatively new 7200 Infocus projector matched with a high end Denon receiver. Since I've gotten it, I occasionally notice lip sync problems, specifically with the audio just slightly ahead of the video. I originally thought this was an HDTivo, but I've seen the problem since with other video sources.

My question is whether my projector is creating a slight delay, and, if so, what can I do about it?

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Does your Denon have an audio delay setting. Mine does, 4802R but I have not had to use it
Mine has an audio delay for room size, but that's it.
It's likely your source component. (tivo, DBS reciever, DVD player etc)

stop and restart to se if fixes, switch channels etc
Audio sync issues are common unfortunately. Given that the audio signal has nothing to do with your pj it is related to the source and the decoding of the digital bit stream which is why you see it sometimes and not all the time. If the pj was "causing" it you would always see it. DirecTv knows about these issues and has in general ignored them to the best of my knowledge. What are you using for an audio in to your Denon? Is it optical? coax? I know that I see more audio synch issues on my OTA HD than on my DirecTv signals and I see it on my Plasma as well as my IF7200. Some decoders do a better job than others as well. Good luck.

The audio in is usually optical, some coax. But if it were the decoding of the audio stream, wouldn't the audio follow the video, instead of preceding it?
A number of these lip sync problems originate with the broadcaster. You'll find that it's bad on one channel, and not on another. It can happen anywhere in the long chain of processors from origin to your theater room, and I'm told it's a bear to track down the origin of the problem.

Not likely to be a projector problem.

Well, I had a big screen TV before the projector and never noticed it. Now I see it most nights.
A room-delay function is the precise, diametric opposite of what you need. It will make the sound arrive even sooner.

You need a lip-sync or A/V sync delay if you wish to correc this at the receiver level. Many better units have this circuit built in and it's controllable in milliseconds.
High quality video de-interlacing/processing adds latency to the video image. I believe the Infocus 7200 uses a Faroudja chip to deinterlace, that chip introduces some latency to the video.
well latency is an issue and I send a 720p signal to the pj so no processing is done by the pj for sat feed however I send it a 480i signal from dvd and it does it all with NO lip sunch issues. These kind of issues have been beat to death on the other forums (processor and directv). As Rogo suggests better pre/pro units allow for an incremental adjustment. Given that it is "random" in its occurence you may not find trying to fix it helps much. Good luck.

I have found that when using DVI the audio sync is off some of the time. If I immediately switch to component the issues are eliminated. I do not know what feed you are using but try switching the feeds.
For those of you wondering how this turned out...

1) There is definitely a delay being introduced via the DLP projector (an Infocus 7200). I got a little test video that runs a ball across the screen against a backdrop of time delay values. It was between 65 and 85 miliseconds delayed.

2) I got the Denon 3805. I adjusted the time delay to 75 miliseconds, and everything is great now.

3) Just so that you know this isn't me convincing myself with a placebo effect, I was watching TV through my ReplayTV tonight, and noticed the lip synching problem again. This made no sense, since I'd adjusted it for 75. When I went into the menus, I found that the audio delay feature wasn't there. The sound mode was set to stereo, and I had to set it to one of the surround modes to get the audio delay feature to show up. Of course, it was set to 0. Set it to 75, and everything is back on track.

My only question at this point is that my dealer has an older model Denon, the 4208R (my memory may be wrong here, but not far off), that's a hundred bucks cheaper and has more power. This is the first amp I've ever had where I actually play loud films around 0, all my other amps were around -20. Should I be concerned that there isn't enough power in the amp to adequately drive my speakers? Should I go the extra step and look at pre-amps for it? I'm inclined to keep the 3805 because I love the automatic setup with the mike (urg, another 60 bucks).
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I've had audio sync problems from time to time. My pre/pro has an audio delay offset function that I have used. I had a particular problem with my JVC DVHS deck. I managed to get things to some sort of normalcy with the delay function. That being said, I couldn't understand why when I first hooked it up, I didn't have that problem. I disconnected all the cables and rebooted the gear and voila, no more problem. Don't ask me why. I don't think that your video display is responsible, unless like others have said, your using heavy duty outboard processing.
I feel like there's a disconnect here. I don't see any other way to interpret that it's the projector. All of my sources, DVD, Tivo, Replay, all evidence a 75 milisecond delay. Before the projector, there was a zero delay. What else could it be?
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