GTO 5355 - JBL Car Audio Service Manual (repair manual). Page 5

Installation Warnings and Tips
• 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.

• Choose a safe mounting location away from moisture. 
• Make sure there is sufficient air circulation at the

mounting location for the amplifier to cool itself.

• Mount the amplifier, using the supplied hardware.

Specifications
• 55W RMS x 4 channels, plus 225W RMS x 1 channel,

@ 4 ohms and 

≤1% THD + N*

• 75W RMS x 4 channels, plus 360W RMS x 1 channel,

@ 2 ohms and 

≤1% THD + N*

• THD + N: 0.03% (rated power @ 4 ohms)
• Signal-to-noise ratio: 85dBA 

(reference 1W into 4 ohms)*

• Signal-to-noise ratio: 104dBA 

(reference rated power into 4 ohms)

• Frequency response: 10Hz – 83kHz and 

20Hz – 250Hz

• Max power: 660 watts
* CEA-2006A-compliant

0 Speaker Output Connectors

• Connect the speakers to these terminals,

observing proper polarity.

• Five-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 the rear speakers,
using the Rear L+ and L– terminals, and 
the Rear R+ and R– terminals. Connect the 
subwoofer to the Sub+ and Sub– terminals.

• Four-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. Connect the
subwoofer to the Sub+ and Sub– terminals

• Three-channel (bridged) operation: Connect

one speaker to the Front R+ and Front L– 
terminals. Connect the other speaker to the
Rear R+ and Rear L– terminals. Connect the
subwoofer to the Sub+ and Sub– terminals.

• Minimum speaker impedance for stereo 

operation is 2 ohms. Minimum speaker 
impedance for bridged operation is 4 ohms.
Minimum subwoofer impedance is 2 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. 4 AWG wire is recommended.
Install an appropriate fuse holder and fuse (80A
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. Refer to

the picture below.

• REM: Connect to the “Remote Out” lead from

the source unit or to a source of switched 
12V+ (ACC).

3 Front Input Connectors (RCA)

• Connect to the front RCA outputs from the

source unit or signal processor.

4 Front Input-Level Control

• Used to match the front input level of the 

amplifier to the output level of the source unit.

• See J for the adjustment procedure.

5 Front Crossover-Frequency Control

• 12dB/octave crossover, variable from 

32Hz to 320Hz.

• See K for the adjustment procedure.

6 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.

7 Power On LED

• Illuminated when the amplifier is on.

8 Subwoofer Input Connector (RCA)

• Connect to the subwoofer RCA outputs from 

the source unit, or signal processor.

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 the adjustment procedure in K.

B Rear Input-Level Control

• Used to match the rear input of the amplifier to

the output of the source unit.

• See J for adjustment procedures.

C Rear Input Connectors (RCA)

• Connect to rear RCA outputs from the source

unit, or signal processor.

D EXT/INT Switch

• If the source unit has a subwoofer output and

you have connected it to the SUB input, set this
switch to the EXT position. Otherwise, set it in
the INT position.

E Subwoofer Remote Level Control Connector

• Connect the Remote Level Control (RLC) here,

using the supplied RJ-11 cable. 

F Subwoofer Level Control

• Used to match the SUB input of the amplifier to

the output of the source unit.

• See J for adjustment procedures.

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
present in the amplifier’s output).

H Subwoofer Low-Pass Filter Frequency Control

• 12dB/octave low-pass filter, variable from 20Hz

to 200Hz. 

• See the adjustment procedure in K.

I DBO (Dynamic Bass Optimization) Variable

• For woofers in tuned (vented) enclosures, set

the Frequency control to a value 10Hz below the
enclosure’s resonance (tuned) frequency.

• For woofers in sealed boxes, set the control to

any value you prefer between 30Hz and 50Hz.

• Set the Boost control according to your 

preference, being careful not to apply 
enough boost to damage your woofer(s).

A DBO High-Pass Filter Frequency control,

variable between 10Hz and 100Hz. See
above for appropriate settings. 

B DBO Boost control provides up to 

12dB of boost, slightly above the high-
pass filter’s frequency. See above for 
appropriate settings.

J Setting Input Level

A Turn all Input-Level controls 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 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 the Rear and Sub Input-Level controls

so that the level of the rear speakers and the
level of the subwoofer are proportionate to the
level of the front speakers, according to your
preference.

K 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 full-range speakers

when a subwoofer is included in the system.

C Crossover setting for subwoofers.
D Crossover setting for systems that include

separate mid-bass speakers driven by the rear
channels, with the BP switch set to “BP.”

Note: Acceptable frequency ranges are indicated 
in gray.

L Remote Level Control

The Remote Level Control, if installed, will allow
you to adjust the level of bass while seated in the
listening position.

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.
Features, specifications and appearance are subject to change
without notice.

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