Installation Warnings And Tips; Speaker Output Connectors; Power Input Connectors; Setting Input Level - JBL GTO504 Service Manual

GTO504
CAR AUDIO POWER AMPLIFIER OWNER'S MANUAL

Installation Warnings and Tips:

• Always wear protective eyewear when using tools.
• Disconnect the negative (–) lead from your vehicle's
battery.
• At the installation sites, locate and make a note of
all fuel lines, hydraulic brake lines, vacuum lines
and electrical wiring. Use extreme caution when
cutting or drilling in and around these areas.
• If the amplifier's fuse must be replaced, use only
the same type and rating as that of the original.
• Choose a mounting location in the trunk or cargo
area where the amplifier will not be damaged by
shifting cargo.
• Make sure there is sufficient air circulation at the
mounting location for the amplifier to cool itself.
• Make sure that the amplifier is mounted securely
using nuts and bolts or the supplied mounting
screws.
• Mount the amplifier so that it remains dry – never
mount an amplifier outside the vehicle.
What's in the Box?
(4) #8 x 2-1/2" Philips panhead screws for mounting
the amplifier
(2) 20A ATC-type fuses
(1) Owner's Manual
Specifications
• 55W RMS x 4 channels @ 4 ohms and ≤1% THD + N*
• 70W RMS x 4 channels @ 2 ohms and ≤1% THD + N*
• THD+N: 0.02% (rated power @ 4 ohms)
• Signal-to-noise ratio: 90dBA
(reference 1W into 4 ohms)*
• Signal-to-noise ratio: 105dBA
(reference rated power into 4 ohms)
• Frequency response: 10Hz – 100kHz (–3dB)
• Max Power: 280 Watts
* CEA-2006A compliant

0 Speaker Output Connectors

• Connect the speakers to these terminals observ-
ing proper polarity.
• Four-channel operation: Connect the front left
speaker to the Front L+ and L– terminals, and
the front right speaker to the Front R+ and R–
terminals. Repeat for rear speakers using the
Rear R+ and R– terminals.
• Three-channel operation: Connect the stereo
speakers to the Front terminals as above.
Connect the single speaker into which the
amplifier's rear channels will be bridged to the
Rear R+ and Rear L– terminals.
• Two-channel (bridged) operation: Connect one
speaker to the Front R+ and Front L– termi-
nals. Connect the other speaker to the Rear
R+ and Rear L– terminals.
• Minimum speaker impedance for stereo opera-
tion is 2 ohms. Minimum speaker impedance for
bridged operation is 4 ohms.
1 Fuses
• Replace only with same type and rating.

2 Power Input Connectors

• +12V: Connect to the positive terminal of the
vehicle's battery. 8 AWG wire is recommended.
Install an appropriate fuse holder and fuse (40A
minimum) within 18 inches 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. Clear
away the paint from the chassis location where
you will connect the ground wire. Use a ring
terminal, tapping screw and star washer.
Factory Bolt Ring Connector
Note: Remove any paint Star Washer
below ring connector.
• REM: Connect to the "Remote Out" lead from
source unit or to a source of switched 12V+
(ACC).
3 Aux Output Connectors (RCA)
• Summed, nonfiltered pass-through output.
Front right and rear right inputs are combined
and sent to the right AUX output. Front left
and rear left inputs are combined and sent
to the left AUX output. Connect to the input
of an additional subwoofer amplifier.
4 Front Input Connectors (RCA)
• Connect to front RCA outputs from the source
unit or signal processor.
5 Front Input-Level Control
• Used to match the front input level of the
amplifier to the output level of the source unit.
• See F for adjustment procedure.
6 Front Crossover-Frequency Control
• 12dB/Octave crossover, variable from
32Hz to 320Hz.
• See G for adjustment procedure.
4
7 Front Crossover-Filter Selector
• LPF – Select for subwoofer(s).
• Flat – Select for full-range speakers when
no subwoofer will be used in the system.
• HPF – Select for midrange speakers or
full-range speakers when a subwoofer is
used in the system.
8 Rear Bass-Boost Control
• Set the Bass-Boost control according to your
preference, being careful not to apply
enough boost to damage your speaker(s).
9 Rear Crossover-Filter Selector
• LPF – Select for subwoofer(s).
• Flat – Select for full-range speakers when
no subwoofer will be used in the system.
• HPF – Select for midrange speakers or
full-range speakers when a subwoofer is
used in the system.
A Rear Crossover-Frequency Control
• 12dB/Octave crossover, variable from
32Hz to 320Hz
• See adjustment procedure in G .
B Rear Input-Level Control
• Used to match the rear input level of the
amplifier to the output level of the source unit.
• See 16 for adjustment procedure.
C Power On LED
• Illuminated when the amplifier is on.
D 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
present in the amplifier's output).
E Rear Input Connectors (RCA)
• Connect to rear RCA outputs from the source
Ground Wire
unit or signal processor.
F Setting Input Level
A Turn all Input-Level controls counterclockwise
to 6V (minimum).
B With a dynamic music track playing, turn head
unit's volume control to the 3/4 position.
C Turn Front Input-Level control clockwise until
the music is so loud that it no longer sounds
clear (distortion is present in the output).
D Turn Front-Input-Level control counterclock-
wise gradually, just until the music sounds
clear, once again.
E Front-level input is now adjusted correctly.
F Adjust Rear Input-Level control so that the
level of the rear speakers is proportionate to
the level of the front speakers according to
your preference.
G Setting the Crossover
A Crossover setting for 5" 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 indicated
in gray.