Control Of Dynamic Range - Gain Reduction And Release Time - Orban 8182A Operating Manual

When
the
8182A
gates (indicated
by
the
GATE
indicator lighting), the
gain reduction
very slowly recovers
to
lOdB
(0
on
the meters).
When
the
GATE THRESHOLD
control
is
set
as
recommended,
the unit
will
be gated during almost
all
low-
to
medium-level
program
material,
and average
gain reduction
will
tend
to
be very close to
lOdB.
Only
when
average
program
material
is
somewhat
high or
low
will the
gain reduction
be
different
than lOdB. This
is
because
levels close to the
nominal
100%
level are
ordinarily
above
the threshold of
gating,
and
this
allows
the
gain reduction
to
recover
normally
so the unit will "ride
gain"
appropriately. Yet,
because of
the
gate,
the
"noise breathing" characteristic of unsophisticated compressors
will
be avoided.
The GATE THRESHOLD
control
should never be
set
below 4
for general
programming
(although
such
setting
may
be appropriate for
some
popular
music
formats
—
if
listening
tests
are passed).
Control
of
dynamic
range
—
gain reduction
and
release time.
The amount
of gain reduction
determines
how much
the loudness
of
soft
passages
will
be
increased, and, therefore,
how
consistent overall perceived loudness
will be.
It is
controlled
both
by
the setting
of the
8182A
Audio Processor's input
attenuator
controls
and gate threshold
control,
and by
the level
at
which
the console
VU
meter
or
PPM
is
being peaked.
lOdB
gain reduction (=
OdB
on
the
TOTAL
MASTER
G/R meter)
is
recommended
for
general
programming
to
produce
a consistent level
from a
wide
variety
of source
audio (mostly voice with
some
music).
Using
less
gain reduction
more
faithfully
preserves the
dynamic
range of
the
source
audio.
Higher
levels
of gain
reduction
are
recommended
for
music videos programming
to
achieve
an
open, yet reasonably
consistent
sound
more
typical of
FM
audio processing.
In general,
increasing
the
amount
of gain reduction decreases the apparent
dynamic
range of the audio. In
extreme
cases, this results in
excessive
pump-up
of
noise,
underscoring,
etc.
Too
little
gain
reduction,
on
the other hand,
will result in
inconsistent
audio
lev-
els:
some
parts
of your programming
will
seem
too loud, others too
quiet.
Less
gain reduction than
recommended
is likely to result in
low-level material's
being
unacceptably
quiet (and therefore
difficult to
understand or perhaps altogether unin-
telligible).
The
release
time
is
the rate at
which
the
gain of
the
compressor recovers
when
the
program
material
gets quiet, yet
is
above
the gating threshold.
Slow
release
times
are
most
appropriate for television audio, as they result in
output density approximately
equal
to that
of
the input audio. (Although the
setting
of
3
recommended
for general
programming
is
nearer
the
word
"FAST"
on
the panel,
when
the
RELEASE shape
control
is
set to
EXP
the net
effect
is
a
slow
release
time since
gain recovery
starts
out slowly
—
see below.)
Faster release
times produce
a denser, louder,
more uniform sound
that
is
appropriate
for
some
popular music
formats.
However, operating with
faster release
times gen-
erally
increases the
danger of
audible side
effects,
including noise breathing.
(Highly
competitive radio formats
are
characterized
by
this
sound,
which
is
really
a side
effect
of trying
to
maximize
loudness
at
the
expense of audio
quality.
Because
television
audiences
would
be
more
likely to
be
annoyed
than
attracted
by one
station's
being
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