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Introduction
Digital image processing within broadcasts and modern displays
(Plasma, LCD, etc.) causes video delay which lets audio arrive a
fraction of a second too soon. This creates the annoying timing
difference we see in lip motion and sound called
lip-sync error
.
However, research at Stanford University¹ in the US statistically
confirmed that presentations with this unnatural phenomenon -
audio leading video
- caused viewers to perceive the material
more negatively - even viewers who did not consciously notice
the lip-sync error.
So lip-sync error is not just a minor distraction but it is the most
noticeable symptom of the larger problem -
sound before its
cause
- which fundamentally undermines the home cinema
experience by contradicting reality.
The HD940 builds on the years of experience we have gained in
lip-sync correction along with the invaluable input we have
received from customers of our previous digital audio delays, the
DD340, DD540 and DD740. And now the Felston HD940 gives
you complete control over audio/video synchronization of your
HDMI AV system. And by delaying audio to match the video
delay you will not only correct lip-sync but also
restore reality!
Users of our other Felston units will be used to the wide range
and precision of delay available. Now the HD940 introduces for
the first time the ability to automatically correct lip-sync error.
Using the audio and video latencies available via HDMI
(depending on the equipment), correction for a TV's processing
time is possible automatically. The HD940 takes sophistication
even further by allowing this correction to vary according to the
video format being watched, all settable by the user.
We appreciate your choosing the Felston HD940 to
restore
reality
to your home cinema and look forward to hearing from
you:
¹B. Reeves, D.Voelker: "Effects of Audio-Video Asynchrony on Viewer's Memory, Evaluation
of Content, and Detection Ability", Research Paper Prepared for Pixel Instruments at
Stanford University