As per the research I did over the NET about Lip Sync Problems with HD, I am assuming it is a very needed feature in the receiver.
Can anyone let me know what is the maximum Lip Sync delay (how many milli secs ) that we should be taking care of using a receiver's "Lip Sync Delay" feature ?
I recommend you have a range between 1 field and 10 fields. A field is half a frame. In PAL, a frame is 40 milliseconds (25 frames per second), which means 1 field equals 20 ms. In NTSC, 1 frame is roughly 33ms. So one field is roughly 16ms.
A bit about my setup:
I have a Felston Digital Audio Delay unit, which has a delay range between 1 and 650 milliseconds. I have a philips LCD TV, which on it own is fine (has analog audio delay built in), but when connected to the AVR, needs about 40ms delay. The satellite picture itself is slightly delayed so it usually accounts for 60ms total delay when watching TV. When playing a DVD, my progressive scan player introduces another 40ms delay, for a total of 100ms. An entry level yamaha will give you 120ms maximum delay, and the better range will give you 200ms. I would opt for the felston unit as it also has customisable preset delays which you can call up at any time. The Felston unit is also extremely well built.
My Yamaha AZ1 can handle up to 160ms. It seems 90ms is around the right range for my setup. Still considering the Felston, since the Yamaha setting is a global setting and the HDMI output of my player is the only source that requires an audio-delay.
How do you adjust your delay? Just eye-balling it, or do you use a specific DVD or scene to adjust?
I use the TV's speakers. My Philips TV has delay circuits built in, which means lip-sync issues are only noticeable when playing audio via an external AVR. Basically, if I increase the TV volume and listen to the TV and the AVR at the same time, I can sync the two by making sure I can not hear any echoes. Once I get this basic setting (40ms for TV, 80ms for DVD playback), I try to eyeball any further delay to compensate for cable/satellite picture delays and DVD mastering mistakes. Currently I use 60ms for TV and 100ms for DVDs. Star Wars DVDs seem to sometime need up to 160ms to look synched. Remember that over compensation (more delay than necessary) is less noticeable than under-compensation. This is because we are used to the speed of light and sound to be different, and because it matched the old days when picture was ahead of sound; so it seems less odd.
ealam_007
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Posted on
Filippo Negroni - you are a genius. Just the tip I've been looking for, and like all good ideas, so simple once you know!!