Operation - JBL PB12 Service Manual

O P E R A T I O N
Power
When the unit is plugged in
and (for the PB12 only) the
power switch is on and no
signal is received, the LEDs on
the front of the unit will turn
red. When a signal is present,
the LEDs will turn green.
Note: It will take several
minutes for the LEDs to turn
Level Control
The subwoofer Level Control
adjusts the volume of the
subwoofer relative to the rest
of the system. Proper level
adjustment depends on
several variables such as
Crossover Adjustments
The Crossover Frequency
Control determines the highest
frequency at which the
subwoofer reproduces sounds.
If your main speakers can
comfortably reproduce some
low-frequency sounds, set this
control to a lower frequency
setting, between 50Hz – 100Hz.
This will concentrate the
subwoofer's efforts on the
ultradeep bass sounds
required by today's films and
music. If you are using smaller
bookshelf speakers that do not
extend to the lower bass
frequencies, set the low-pass
crossover control to a higher
setting, between 120Hz –
150Hz. This control is not used
when the LFE switch is in the
"LFE" position.
from green to red after the
input signal to the subwoofer
is removed. Due to JBL's
unique, high-output, high-
efficiency amplifier design,
power consumption is minimal
when the subwoofer is not
receiving a signal. Of course,
the PB12 subwoofer can be
room size, subwoofer
placement, type of main
speakers and listener position.
Adjust the subwoofer level so
that the volume of the bass
information is pleasing to you.
LEVEL
Min
LFE
PHASE
0º
CROSSOVER
FREQUENCY
50Hz
PowerBass PB10
L
LINE LEVEL IN
For LFE use L or R
HIGH
LEVEL
+ –
HIGH
LEVEL
OUT
60Hz, 160W
PowerBass PB10
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
turned off, whenever desired.
The PB10 must be unplugged
if you do not wish to leave it in
auto (standby) mode.
LEVEL
Max
NORMAL
180º
CROSSOVER
FREQUENCY
150Hz
PowerBass PB12
R
LINE LEVEL IN
L
IN
R
+ –
L
R
120V
ON
POWER
PowerBass PB12
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
Min Max
LFE NORMAL
PHASE
0º 180º
150Hz
50Hz
L R
For LFE use L or R
L
HIGH
LEVEL
IN
R
L
HIGH
LEVEL
OUT
R
120V
OFF
60Hz, 160W
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