GT5-A3001 - 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
• 175W RMS x 1 channel @ 4 ohms and 

≤1% THD + N*

• 225W RMS x 1 channel @ 2 ohms, 14.4V supply and

≤1% THD + N*

• 300W RMS x 1 channel @ 1 ohm, 14.4V supply and

≤1% THD + N*

• THD + N: 0.05% (rated power @ 4 ohms)*
• Signal-to-noise ratio: 95dBA 

(reference 1W into 4 ohms)*

• Signal-to-noise ratio: 120dBA 

(reference rated power into 4 ohms)

• Frequency response: 10Hz – 300Hz (–3dB)*
• Total peak power: 600 watts
* CEA-2006A-compliant

0 Speaker Output Connectors

• Connect the subwoofer to these terminals, 

observing proper polarity. Either + or – 
terminal may be used. Minimum total 
impedance is 1 ohm.

1 Fuses

• Replace only with the 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. 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 Aux Output Connectors (RCA)

• Nonfiltered pass-through output. Connect to 

the input of an additional amplifier. 

4 Input Connectors (RCA)

• Connect to the RCA outputs from the source unit

or signal processor.

5 Input-Level Control

• Used to match the input level of the amplifier 

to the output level of the source unit. 

• See 9 for the adjustment procedure.

6 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).

7 Low-Pass Filter Frequency Control

• 12dB/octave low-pass filter, 

variable from 32Hz to 320Hz.

• See A for the adjustment procedure.

8 Power On LED

• Illuminated when the amplifier is on.

9 Setting Input Level

A Turn Input Level control counterclockwise to

6V (minimim).

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

bass output is proportionate to the output of
the high-frequency speakers, according to
your preference.

D Input level is now adjusted correctly.

A Setting the Crossover

A Crossover setting for subwoofers.
Note: Acceptable frequency ranges are indicated 
in gray.

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