Plasma screen picture delay/lip sync

In message , just me
writes
No, I'm not comparing with different tape formats, but what I very
carefully described as "domestic audio cassette tape" recorders which,
even in their modest-priced forms can sound terrific. EG My Denon
DRM740 - approx £240 12 years ago - which sounds outstanding with any
half-decent cassette and a sensibly recorded track.

I'm not comparing different tape formats either. I'm comparing different
quality players. Most people with a cassette deck didn't pay £240 for
it, more like £24
The format is the same. The sound quality is vastly different.



I agree that plasma displays can be made to not give bad lip sync
problems. It doesn't mean that all designs out there are made that way
at the moment.
Lip sync is most definitely out there!

So are you saying that you feel lip sync ISN'T an inherent plasma
problem?

I'm saying it ISN'T inherent to generic plasma technology, it IS in
current implementations for MANY, but not all, displays.

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So are you saying that you feel lip sync ISN'T an inherent plasma
problem?

I'm saying it ISN'T inherent to generic plasma technology, it IS in
current implementations for MANY, but not all, displays.

Fair enough!

My experience has shown that the majority of lip-sync issues witnessed have
been caused by digital broadcasting and NOT by the display device. I visited
a friend just this week who was complaining of lip sync problems. Switched
over to the analogue tuner and the problem vanished. A millisecond here and
a millisecond there may combine to exascerbate the problem though. I
remember a few years ago a combination of a badly mastered DVD and a certain
generation of Sony DVD firmware combined to cause irritation (can't remember
the disc title) - both were out in the same direction.

Curiously still no answer to the questions I asked the OP, although as
someone else has suggested, if the problem originates from a digital
set-top-box, a simple power down and up usually solves the problem. And if
the screen is faulty then it should be returned/repaired.

In message , just me
writes
My experience has shown that the majority of lip-sync issues witnessed
have been caused by digital broadcasting and NOT by the display device.
I visited a friend just this week who was complaining of lip sync
problems. Switched over to the analogue tuner and the problem vanished.
A millisecond here and a millisecond there may combine to exascerbate
the problem though.

I think the last sentence could have a lot of truth to it.
But I have seen some displays driven straight off (expensive) DVD
players that have too bad a problem to make me able to watch the
picture. But then I am a fussy ******* :-)

No doubt they'll sort if out soon as the processing speeds up.

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Thanks for all the comments/suggestions.

Just to answer some of the questions:
The delay occurs on my (admittedly quite old now) Sky box, my DVD and my VCR
(which are all connected via SCARTs). Also noticed it when I connected Sky
via S-video. Haven't tried it with analog connection yet (maybe this
weekend....)
My screen has a built-in tuner but I have no aerial on my house and live in
a valley.I was tempted to hook an aerial up and see if this also has a
delay, but this wouldn't solve my DVD/Sky problem so didn't bother.
Problem is worse on some Sky channels than on others (but I'd noticed that
Sky/my Sky box seemed to have sync issues before buying my screen).
Amusingly enough, on some of what I remember to be badly sync'd Sky
channels, I now get proper sync.

I guess I've just got to live with it or buy another amp. Anyone any
suggestions on a good and reasonably cheap 5.1/6.1 amp that will allow me to
dial in delays for all channels?

P

Hello all

Alec - I think the various Digital delay projects that are on the way
have all suffered from 'over specifying' and ending up either too
complicated and/or too expensive.

Its interesting to note that the latest batch of external video
processors all seem to have recognised this issue and are now
including Digital delays on the video inputs - though these are not
exactly 'low cost' solutions and aimed at the Plasma and Projector
market.

Phil - most of the big name manufacturers now offer AV Receivers with
Digital Audio delay; though your looking at near £800 in most cases
for a unit that includes this feature.

Keep in mind for two channel use you can use something like the
Behringer in the Tape loop of most amps so even though the Behringer
only has one set of inputs you can utilise it for multiple sources
using the amps switching facility.

Best regards

Joe

On Wed, 21 Jan 2004 23:02:01 -0000, "just me" wrote:

Bottom line is that the set *shouldn't* give you this trouble - plasma
screens do not inherently have lip sync problems

'Shouldn't' and 'do not' however are two different things ......

The first sentence should read *shouldn't* but many do....

It's been my experience that most (and by that I mean close to 100%) of
plasma screens do not render lip-sync problems. People often see lip-sync
problems which may be caused by souce problems which went unnoticed
previously, or occur because screen and Digibox are bought simultaneously.

Well, having actually *measured* the delay through a variety of
plasmas and LCD's as part of my job, I can tell you that you are
wrong! The average delay through a plasma is 60mS, or around a frame
and a half. Of course this depends on a variety of factors, such as
the design of the indivisual screen and strangely the connection
method.

Some screens may well delay their internal audio paths to match the
video delay of the display, but of course this is irrelevant if you're
sending your audio to an external decoder/amplifier.

Which is why there are an increasing number of amps that offer a
global delay function...

Steve (senior BBC engineer!)

The Doctor Who Restoration Team Website
http://www.restoration-team.co.uk

Which is why there are an increasing number of amps that offer a
global delay function...

Steve (senior BBC engineer!)


And how exactly does that help when your experiencing delays on BBC1 and 2
but not on channel 4?? and some channels on NTL but not other!
regards
Si

"Steve Roberts" wrote in message
...
On Sun, 25 Jan 2004 09:38:07 -0000, "Sly"
wrote:

And how exactly does that help when your experiencing delays on BBC1 and
2
but not on channel 4?? and some channels on NTL but not other!
regards

It doesn't - that obviously points to the broadcast chain being out of
sync.

Indeed - but if you've got the correct Amp you can at least adjust it!!!

'Digital' TV - don't you just love it!

Justin.

In message , Justin
Cole writes
And how exactly does that help when your experiencing delays on BBC1 and
2
but not on channel 4?? and some channels on NTL but not other!
regards

It doesn't - that obviously points to the broadcast chain being out of
sync.

Indeed - but if you've got the correct Amp you can at least adjust
it!!!

But does it? The point is, different channels from the same source have
different delays!?! How can you adjust this (without obviously resetting
the delay each time you change channel) in the amp???

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Personal email for Gareth Jones can be sent to:
'usenet4gareth' followed by an at symbol
followed by 'uk2' followed by a dot
followed by 'net'
__________________________________________________

"Gareth Jones" wrote in message
...
In message , Justin
Cole writes
And how exactly does that help when your experiencing delays on BBC1
and
2
but not on channel 4?? and some channels on NTL but not other!
regards

It doesn't - that obviously points to the broadcast chain being out of
sync.

Indeed - but if you've got the correct Amp you can at least adjust
it!!!

But does it? The point is, different channels from the same source have
different delays!?! How can you adjust this (without obviously resetting
the delay each time you change channel) in the amp???

That was my point... Annoying that it is, you *can* correct it.

I've created a macro on my remote control that quickly adjusts the delay by
+5 or -5ms. Sorted.

Justin.