Sound

[DonGrafton]

I have a new Hitachi 42HDS52A - using "Air" to receive and the sound does not match the video. There is a varying delay - station to station - from 1 to 3 seconds of delay in the sound. Hitachi says it's the station - but all of them? Is this a common problem? I have good video reception on all stations - except 18-1 (none). Should I call the repairman?

[StarvingForHDTV]

It is your equipment that is causing the problem.

[Nels Harvey]

Occasionally the sound will be out of sync with the picture in the digital format, but the engineering departments of the stations take pains to prevent it from occurring.  I have observed a group of engineers adjusting the audio delay to eliminate as little as a single frame delay, or 1/30th of a second time shift on recorded material.

Digital video takes time to be encoded, then decoded in your receiver.  Since the audio doesn't need so much time to be encoded and decoded, digital delay circuits are employed to make the timing come out correctly at the source.

I have a Hitachi LCD, receive all the local digital signals, and do not experience out of sync audio very often at all, and certainly not one to three seconds of error.  Now, if you listen to a old TV's audio and watch the digital video on the new receiver, there will be a very noticable delay, of  three, or even more, seconds from one TV to the other.  That delay can't be avoided.

Nels....