Audo delay in Hitachi plasma TV [Archive] - Audio & Video Forums


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05-20-2006, 06:01 PM
I seem to have an audio delay in my Hitachi 55HDS52 plasma tv. When I play an DVD from my Denon1920 DVD player into my Marantz Home Theater receiver, there is an audio delay to the plasma tv, thus the lip synchronization is off. I tried changing the speed on the DVD player, but the audio delay in the TV continues. What can I do to fix this? Thanks, everybody:17:

05-21-2006, 05:21 AM
This is a tough nut, so bear with me. The reason for the lip-sync problem is video processing that makes the picture lag behind the sound. This processing can happen anywhere along the chain--from broadcasters, to an STB, to a TV, or, from a DVD, to a DVD player, to a TV. Many of the newer A/V receivers have a range of manual adjustments to alleviate it, as do some DVD players and most current stand-alone video processors. Some companies even produce lip-sync devices that interface with A/V receivers. Also, various components have their own automatic adjustments for signals that they generate, and, unfortunately, some have none at all.

If the Denon 1920 can't delay the audio sufficiently (a little surprising), then the problem would appear to be happening further down the road where none of the remaining components can restore proper alignment. (I'm assuming that your A/V receiver doesn't have a lip-sync adjustment.) Here are two experiments: First, if you aren't sending an upscaled/deinterlaced video signal from the Denon to the Hitachi, do so. This tactic may remove some of the burden of processing from the Hitachi, which conceivably could be causing the audio-video disconnent. The complication is, however, that even this strategy won't disable all of the Hitachi's video processing; the TV will probably still do some scaling, as well as other elective or undefeatable chores. Under this scenario, whatever you can do to keep the Hitachi from meddling with the signal might be worth a try.

If the above doesn't pan out, send an interlaced signal from the Denon to the Hitachi w/o any scaling--that is, don't send 720p or 1080i via the Denon's HDMI output--and bypass the receiver completely with the audio. Let the Hitachi handle all video processing and play all audio via its own inputs through its own speakers (forget the matter of fidelity for a moment). If the lip-sync problem now disappears, the Hitachi will have introduced the requisite audio delay to compensate for its own video processing. At least you'll know that the lip-sync problem isn't inevitable.

If you want to bring the Denon's scaling/deinterlacing and the receiver's audio back into the mix, you'll have to buy an external unit to delay the audio, or invest in another receiver to do the job--unless we've missed something hidden in the menus of your current components that is capable of rectifying the situation.

05-21-2006, 10:07 AM
i don't believe the Hitachi is the issue, since it happens only with DVD, you should adjust the delay time in the Denon bass management or (if it is avaiable) lip-sync adjustment on the receiver; Which Marantz do you have? Is the DVD player connected with HDMI? Are you using the Hitachi as the center channel?

05-21-2006, 01:27 PM

I would have thought that the Denon would be able to cure a lip-sync problem that originated with it, but apparently not in this case. To complicate matters, someone in my neck of the woods with a current Hitachi plasma is experiencing lip-sync problems with cable but not with his older Samsung DVD player, which does minimal processing on its own. He isn't using an STB for cable, just running the feed straight into his set. The reason for the cable's audio delay might be that it isn't getting the benefit of an automatic sync adjustment that an STB might provide, leaving the Hitachi to process the video in complete isolation from the audio. Why the audio from his DVD player doesn't exhibit the same delay is hard to tell. It might not be perfectly in line, but close enough to fool the eye. The older Samsung could also be sending its signal along at a faster clip than altart's more elaborate Denon. We might need to know more about altart's predicament, but I can imagine that the video buffering in the Hitachi, when severed from any corrective audio circuitry, could result in a visible time lag for DVD that a video tuner, for one reason or another, can avoid.


05-22-2006, 09:46 AM
interesting diagnosis; i have experienced this before using a cablecard with the Hitachi 42" Directors' series. A quick simple fix was a upgrade card from Hitachi tech support; I don't know if his model has that capability but its' worth a try. I'd wager the issue still lies within the DVD or receiver. He could narrow this down by running the DVD player directly to the display or just audio from the DVD to receiver and video to display

05-22-2006, 10:00 AM
Sometimes troubleshooting an A/V problem is little like trying to understand a funny situation that didn't happen to you: "You had to be there." Anything altart can do to narrow down the options wouldn't hurt, but I fear we've lost him. Maybe he found some smarter people to help him.

05-22-2006, 06:59 PM
you guys are good. My marantz is an older model, SR-92 mk, which works fine but is probably the weak link here. What models/manufactures would you reccomend, the Yamaha has audio delay.

05-23-2006, 04:06 AM
I'm glad you didn't flee. You might start a new thread to redirect interest--something like "Wanted: Affordable Receiver with Good Lip-Sync Control." People on this board know their receivers. I'm not one of them. Maybe AVMASTER does.

05-25-2006, 10:00 AM
i'm not an authorized Yamaha dealer but the HTR5960 sure looks like the way to go; i'd be very curious to know if this does fix the problem