Advertisement
inns | ICP ICEIR
OPERATION
e A multichannel
amplifier system
includes
several addi-
tional
controls
and adjustments
as compared
with
an
ordinary
stereo
system.
To
get the best performance
from your multichannel amplifier system, you must set
these
controls
and
adjustments
properly.
Universal
pro-
cedures for adjustment of multichannel amplifier systems
cannot be described, because the resulting performance
varies
from
one
system
to another,
depending
on the
quality
and characteristics
of the preamplifiers,
power
amplifiers, and speakers used, and also the room acous-
tics. Therefore, at the final stage of adjustment, you may
have to depend on your own ears for best performance
of your system.
® Before
turning
the
SF-700
on,
make
sure
that
all
connections have been properly made. It is advisable to
turn off the power switches of the power amplifiers or
to
reduce
the
volumes
of the
power
amplifiers
to
minimum
whenever
changing
the
switch
or
control
settings of the SF-700.
THREE-WAY SYSTEM
1. Turn the LEVEL
LOW, LEVEL
MID
and LEVEL
HIGH
controls
fully counterclockwise.
(This sets
the output
levels to minimum.)
2. Check the brochures of the speakers to be used and find
the recommended crossover frequencies for them. Set the
LOW-MID
and MID-HIGH
switches of the SF-700 to the
recommended crossover frequencies.
T
8. Use the SLOPE
switches for selecting the cut-off charac-
WOOFER
teristics of the low-, middle- and
high- channel
ranges.
The
optimum
cut-off
characteristic
for one
frequency
range is usually determined
from the cut-off frequency
aa
of the speaker to be used (beyond which the speaker is
unable to reproduce sound ) and the crossover frequency
an
a
ern
=
ie
of the
particular
frequency
range.
For
example,
if a
3am
reqp7ocr
(12542)
Ctiz)
FREQUENCY IN He
woofer's cut-off characteristic is 2 kHz and it is used at
Fig. 11
1 kHz crossover, optimum performance may be obtained
:
with
the LOW
SLOPE
switch
set to a cut-off of 18
TWEETER
dB/octave. On the other hand, if the same woofer is used
Tedb/oct
12B/oct eltei/pct
for 125 Hz or 250 Hz crossover, optimum performance
Ca
may
be obtained with the LOW
SLOPE
switch set to a
|
cut-off of 6 dB/octave. In general, if the gap between the
crossover frequency selected and the cut-off frequency of
|
|
the speaker is small, 18 dB/octave is recommended as the
7
Be
TREE
ae
a
cut-off characteristic, and if the gap between the cross-
FREQUENCY IN' Hz
over frequency selected and the cut-off frequency is large,
Fig. 12
6 dB/octave
or 12 dB/octave
is recommended
as the
cut-off characteristic of the particular frequency range.
4. Set all volume controls of the preamplifier to the lowest
levels and then turn the amplifiers on.
5. Turn
the
preamplifier
volume
controls
to their
mid-
points, turn
the level controls
of the SF-700
to their
midpoints, and start playing a record.
Advertisement
