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a SPEAKER OUTPUT CONNECTORS
• Connect the speakers to these terminals,
observing proper polarity.
• Two-channel operation: Connect the left speaker
to the L+ and L– terminals and the right speaker
to the R+ and R– terminals.
• One-channel (bridged) operation: Connect the
single speaker to the R+ and L– terminals.
• Minimum speaker impedance for two-channel
operation is 2 ohms. Minimum speaker impedance
for one-channel (bridged) operation is 4 ohms.
b FUSE
• Replace only with the same type and rating.
c POWER INPUT CONNECTORS
• +12V: Connect to the positive terminal of the
vehicle’s battery. 10 AWG wire is recommended.
Install an appropriate fuse holder and fuse (15A
minimum) within 18" (460mm) of the battery. Make
sure the wire is not damaged or pinched during
installation. Install protective grommets when
routing wires through the firewall or other sheet
metal.
• GND: Connect to the vehicle’s chassis. Refer to
the picture below.
Factory Bolt Ring Connector
Ground Wire
Note: Remove any paint
below ring connector.
Star Washer
• REM: Connect to the “Remote Out” lead from the
source unit or to a source of switched 12V+ (ACC).
d INPUT CONNECTORS (RCA)
• Connect to the RCA outputs from the source unit
or signal processor.
e INPUT-LEVEL CONTROL
• Used to match the input level of the amplifier to the
output level of the source unit.
• See k for the adjustment procedure.
f POWER ON LED
• Illuminated when the amplifier is on.
g PROTECT LED
• Illuminated under any of the following fault
conditions: battery over/under voltage, short circuit
in speaker wires, amplifier is too hot, amplifier’s
output circuit has failed (DC voltage is present in
the amplifier’s output).
h CROSSOVER-FREQUENCY CONTROL
• 12dB/octave crossover, variable from 32Hz to
320Hz.
• See l for the adjustment procedure.
i CROSSOVER-FILTER SELECTOR
• LP (SUB): Select for subwoofer(s).
• FLAT: Select for full-range speakers when no
subwoofer will be used in the system.
• HP: Select for midrange speakers or full-range
speakers when a subwoofer is used in the system.
j BASS-BOOST CONTROL
• Provides 6dB of boost at 50Hz. Set the Bass-
Boost control according to your preference, being
careful not to apply enough boost to damage the
speaker(s).
k SETTING THE INPUT LEVEL
A Turn Input-Level control counterclockwise to 6V
(minimum).
B With a dynamic music track playing, turn the
head unit’s volume control to the 3/4 position.
C Turn Input-Level control clockwise until the
music is so loud that it no longer sounds clear
(distortion is present in the output).
D Turn Input-Level control counterclockwise
gradually, just until the music sounds clear once
again.
E Input level is now adjusted correctly.
l SETTING THE CROSSOVER
A Crossover setting for 5" (130mm) or larger full-
range speakers when no subwoofer is included
in the system.
B Crossover setting for midrange and/or full-range
speakers when a subwoofer is included in the
system.
C Crossover setting for subwoofers.
Note: Acceptable frequency ranges are indicated in gray.
This product is designed for mobile applications and is
not intended for connection to the mains.
A valid serial number is required for warranty coverage.
GT-X424 Car auDIO POwer aMPlIFIer Owner’s Manual