Orban 674A - 4: Recording Studio Techniques

The amount
of bass
boost
is
primarily
limited
not by
subjective
considerations
but
by
available
amplifier
power
and
loudspeaker
bass
power-handling
capacity.
For
maximum
capability,
bi-amping is
recommended
because
the bass
amplifier
can be
clipped
occasionally
without
causing
obvious
harshness.
In this case,
the
674A can
also
be used
as an
electronic
crossover.
In all
cases,
the
setting
of
the
674A low
frequency
TUNING and
BANDWIDTH
controls
is
quite critical
in obtaining
bass
that
is
punchy,
"tight",
and
sensual,
without
being
"boomy"
(like
"jukebox
bass").
Correct
settings
will vary
considerably
with
loudspeaker
type
and room
acoustics.
In particular,
satisfactory
results
cannot
be
obtained
with a
horn-loaded
bass
system
with a
cutoff
frequency
above
40Hz.
Trying
to
boost bass
below
the
cutoff
frequency
of
the
horn will
cause
severe
distortion
and
also has
the
potential
of
damaging
the
drivers.
We do
not
recommend
that the
D.J. be
permitted
to
operate the
674A
in
the
course
of
his
normal
activities.
The
674A
should
be
adjusted
once by
the
installing
contractor
to
the
manager's
specifications,
and
then
locked up.
If
the
D.J. is to be
provided
with equalization,
sufficient
power
to
correct
the
sound of
inadequate
records
can be
supplied by a
simple
5-band
graphic
equalizer
with
more
limited
range.
If the sound
contractor has
access
to a
third-octave
real-time
analyzer
and
pink-
noise
source,
these
can be
of
substantial
aid in
adjusting
bands
2-7
for
flat
acoustic
response
in
the
midbass
and
midrange.
Coloration
here is
undesirable,
and can
cause
customer
edginess.
It
can also
interfere
with
conversation.
For the
same
reason,
excessive
treble
boost
should be
avoided
because of
its
potential
for
subliminal
irritation.
If
a
third-octave
analyzer is
available
to
monitor
the
acoustic
response
of the
system,
it is
not necessary
or
desirable
to exactly
match the
channels
in the
frequency
range
below
200Hz
according
to
Stereo
Matching
above.
This is because
different
loudspeaker
locations
will
ordinarily
produce
different bass
balances
jn
the
room unless
the
room has
been
acoustically
designed
and is
symmetrical
(like a
good recording
studio
control
room).
In a
dance bar,
the chances
of this
occuring
are
slight, to
say the
least!
It is
quite acceptable
to
adjust
the
two
674A channels
substantially
differently
below
200Hz to
smooth out
standing
waves,
resonances,
and the
like.
Above
200Hz,
equalization
is
much
more useful in
correcting
the
response
of
the
loudspeaker
than
in
correcting
room
acoustics.
If the
loudspeakers
are
reasonably
well-matched,
the
equalizer
channels
should
therefore be
adjusted
to also
be
well-matched
above
200Hz.
If the
"A"
and
"B"
channel curves
differ
greatly,
this often
results
in the
system's
being
well-equalized at
only
one
place in
the room
(where
the
measuring
microphone
was
located)
at
the expense
of
other
locations
which
may
have their
problems
exaggerated!
4:
RECORDING
The
674A can be
used
in
the
recording
studio just
about
anywhere
that a
\C
conventional
equalizer is
used.
Most
studios
find
at
least
two
channels
of patchable
Parametric
Equalization
to
be
invaluable
in
cleaning
up
"difficult"
tracks
that
the
internal
console
equalizers
can't
handle.
If
a
track
is
plagued by
hum or
other
interference of
fixed
pitch,
the
674A
can
be used
in
its
narrowband
notching
mode
(BANDWIDTH full
CCW;
EQ
at
-l6dB) to
reduce
the
level
of
the sound
and its
most
important
harmonics by
l6dB,
which is
often
sufficient to
render
it
inaudible.
The
notching
of
each
harmonic requires
use
of a
separate
band.
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