Operation - JBL PowerBass PB12 Service Manual

PB12

OPERATION

Power
When the unit is plugged in
and 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.
Level Control
The subwoofer Level Control
adjusts the volume of the
subwoofer relative to the rest
of the system. Proper level
adjustments depend on several
variables such as room size,
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.
Note: It will take several
minutes for the LEDs to turn
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.
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 PB12
L
LINE LEVEL IN
For LFE use L or R
LEVEL
+ –
LEVEL
ON OFF
POWER
PowerBass PB12
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
10
Max
NORMAL
180º
150Hz
R
L
HIGH
IN
R
L
HIGH
OUT
R
120V
60Hz