— 20 —
rection Rate
of
1.75
(dB/sec), (Max)
Gain
of
+18.0
(dB), and a
Win-
dow
setting of
6dB
(±3dB) as shown here:
Using Test
Tones…
or Not
Although a “zero-VU” test tone may certainly be used during
DAVID IV setup, input gain is most accurately set with actual
program material. Here’s why.
Audio levels are typically measured and monitored in any of
several different manners. The traditional US mechanical “VU”
meter and the European “PPM” (Peak Programme Meter) each
adhere to audio industry measurement standards based on ex-
haustive studies. But there are many knock-offs and alternative
level-indicating gizmos as well, few of which have traceability
to any recognized standard. Substandard meters may have
floppy mechanical movements or take the form of flashy LED
and other bargraph readouts, or they can be fancy and colorful
computer screen displays.
But compliant or not, all these devices have their own response
to, and provide their own representation of, program peak and
average levels. What’s more, board operators lend their indi-
vidual interpretations to what they see, assuming that they are
even paying attention to meters in the first place.
Adjusting
Input Gain
Return to the
Setup / Audio Input
menu:
Next,
turn
the jog wheel to position the brackets around the
Digital Gain
or
Analog Gain
slider, whichever is appropriate to the
input you have selected.
Push
the jog wheel to enable that slid-
er so that you can then
turn
the jog wheel to dial-in the re-
quired gain.
With program material playing, adjust
Digital Gain
or
Analog Gain
so that the front-panel AGC gain indicator (the
AGC/GATE
LED
bargraph) hovers around
0dB
most of the time. This will show
that AGC action is more or less centered and working in its
‘sweet spot.’
The DAVID IV AGC is a gain-riding function with a dual correc-
tion rate. Don’t rush this step as there will be some delay be-
fore the AGC meter settles-down each time the slider is adjust-
ed.
Summary of Contents for 719
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