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A reference chart relating control adjustments to desired sonic characteristics is
found at the end of this Part.
HOW TO ADJUST
( Refer to Fig. 4-5 in Part 4.)
THE SETUP CONTROLS
The BASS COUPLING control:
Everything else depends on how you adjust it.
The
BASS
COUPLING
control
determines
the
extent
to
which
the
gain
of
the
"Bass"
band
VCA
is
controlled
by
the " Master"
band's
gain- control
voltage.
In
"wideband" mode ( control fully CW), full " Master" control voltage is applied to the
"Bass" VCA, so that if no additional control voltage were generated by the " Bass"
control circuitry, the gains of the " Master" and "Bass" channels would track exactly
and frequency balances would be perfectly preserved.
However,
when
strong
bass ( below
200Hz)
occurs,
the "Bass"
control
circuitry
generates
further control
voltage for the " Bass" VCA, reducing " Bass" gain
even
more
and avoiding possible overload of the following peak limiting system due to
excessive bass.
In " independent" mode ( control
fully CCW), no " Master" control
voltage
is applied
to
the " Bass"
VCA.
Therefore,
in
this
mode,
the " Bass"
band
operates
entirely
independently of the " Master" band, and frequency balances between the two bands
may
be
made
more
uniform ( regardless
of
the
original
frequency
balance).
The
setting
of
this
control
is
influenced by
the
type
of
program
material
you
usually
broadcast
and
by
your
taste
in
signal
processing.
Try
experimenting!
"WIDEBAND" mode ( BASS COUPLING close to " 10") makes the output
sound
most
like
the
input.
OPTIMOD-TV
is
usually
operated
favoring
this
mode
because it minimizes the amount of pump- up of low frequency noise ( like hum
or
stage
rumble).
However,
it
is not suited for
very
fast release times
and
ultimate loudness. Using the EXPonential RELEASE SHAPE makes it practical
to
do
faster
gain
riding
in
this
mode
while
still
retaining
the " texture"
of
slower release times.
Because setting the BASS COUPLING control at " 10" will sometimes cause a
bass loss ( because the " Bass" compressor can never take
more gain
than the
"Master"
compressor,
and
will
sometimes
take
less),
the
most
accurate
frequency
balance
will
often
be
obtained
with
this
control
between " 7"
and
"10". The setting depends of the amount of gain reduction and the setting of
the RELEASE TIME control. The control
is most readily adjusted by watching
the BASS G/R and COMPRESSION G/R meters and adjusting the control until
the meters track as closely as possible.
"INDEPENDENT" mode ( BASS COUPLING at " 0") is most appropriate for pop
music. With slower release times ( closer to " 10") and LINear release shape, it
sounds
very
open, natural,
and non- fatiguing.
It will
provide a bass boost
on
some
program material which is bass- shy. It may be desirable to temporarily
"retune"
OPTIMOD-TV
to
this
mode
for
rock
concerts
or
similar
musical
programming.
With
fast
release
times ( closer
to " 0"),
the
INDEPENDENT
mode
provides
maximum uniformity and density on smaller sets with underpowered amplifiers
and
small
speakers.
Even
with
potential
bass
noise
pump- up
problems,
INDEPENDENT
mode
will
usually
create
a more
pleasing
sound
than
5-4
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