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Old 18th Jun 2021, 10:13 am   #2363
Craig Sawyers
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Join Date: Nov 2010
Location: Oxford, UK.
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Default Re: The Audiophoolery Thread.

Quote:
Originally Posted by dglcomp View Post
Quote:
Originally Posted by Craig Sawyers View Post
We were at an Eagles concert pre-Covid, and because of the distance to remote places in the audience (like where we were) there were monster screens showing the band.

The problem was, the visible playing on the stage was out of sync with what was on the screen - it looked really weird. Until I twigged what was happening.

The image from the screen goes at speed of light to the audience member (so pretty much instantaneous). But the sound took perhaps 0.3 seconds to arrive. So the video signal is delayed with respect to the sound by 0.3 seconds so that everything is back in sync. Anyone sufficiently close to the stage to not need the screens simply sees the band and the sound live.

I told this to my 36 year old son, a guy who has been to several big music festivals. He replied that it was obvious, and big venues have done that for quite a long time.

Craig
The delay is inherent in the video system rather than being inserted, all LED walls have some amount of processing delay. The only delay that is generally used at concerts is for the speakers themselves, used to align any speakers further back from the main set to stop echoing.
Look at most festivals and you will have the main hang of speakers at the stage and then delay towers further back.
The son in question is a major project manager for AV systems, including every AV system installed here https://www.samsung.com/uk/explore/k...ross/discover/ including a 6m x 4m 0.3mm pixel pitch curved screen. He knows as much as there is to know about video processing delay. So I tend to trust what he says about purposely delayed video are large concert venues.

Craig
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