Stereo And Multichannel Operation; Speech-Activated Ducking - Orban 424A Operating Manual

Stereo
And
Multichannel Operation
The two
channels
of the
424A
may
be strapped by
means
of the
INDEPendent/COUPLED
switch
to
assure stereo tracking and
stable imaging.
In
addition,
any
reasonable
number
of
422A's
or
424A's can be tracked by respectively
paralleling
their rear-panel
STEREO CPL
and
GATE CPL
terminals.
All
compressor/limiter
VCA's
will
then track the channel
requiring
the
highest
amount
of
gain
reduction.
Provided
that the
GATE
THRESHold
controls of
all
units
are
set
identically,
all
units
will
remain ungated provided
at
least
one
unit
receives
sufficient
input level
to ungate.
All
operating controls are
usually set identically.
The
de-essers
remain independent.
Speech-
Act
i
voted Ducking
of
Music
Speech-activated ducking
of
music
is
one unusual capability which requires the use
of
two
(or
more)
channels with the controls
set
in
a unique way.
In
this
broadcast-
oriented
application, the
level
of the
music
in
the on-air mix
is
automatically
reduced whenever speech
is
present.
A
424A
or
two
422A's,
in
COUPLED
or
strapped mode, must be
used.
Channel "A"
is
used
for the speech,
and Channel
"B"
for
the music.
Apply
the speech
to
Channel
"A",
and
adjust the
"A" operating
controls to
produce
fast
attack and release
times,
with the compressor/limiter
OPerate/DEFEAT
switch
to
OP.
Set the
"A"
GATE
THRESHold
control
OFF
(fully
CCW).
Apply
the
music
to
Channel
"B", set
its
compressor/limiter
OPerate/DEFEAT
switch
to
DEFEAT,
and
set
its
IDLE
GAIN
control
to "0".
Adjust the "B"
INPUT
ATTENuator
so
that the
VCA LEVEL
meter
never enters the red
even on
the
highest
peaks
of the music.
Speech appearing
at the
CH
"A"
input at
a
level
high
enough
to
cause
gain
reduction
in
CH
"A"
will
cause
equivalent gain reduction
in
CH
"B", thus
ducking
the
music automatically during speech.
The RATIO
control determines
if
the
music
level
is
reduced
in
direct proportion
to
the speech
level (high
RATIO),
or less
than
proportionately
(low
RATIO). The
setting of the
INPUT ATTENuator
primarily
determines
the
depth
to
which
the
music
is
ducked
(the
more
gain reduction, the
more
ducking).
The
outputs of the
"A" and "B" channels
(i.e.,
speech and
music)
may
be
mixed
in
an
external mixer
in
any proportion desired.
The
original
speech source
may
even
be processed by another
424A
with
different settings,
processed by other equipment,
or
left
unprocessed.
By
analogy,
a
similar
setup
can be used
to
modulate any
signal
by
the envelope
of
any
other
signal.
The range
of the
ATTACK
and
RELEASE
TIME
controls define
the ability of
this
setup
to
track rapidly-varying envelopes.
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