Harman JBL GX-A422SI User manual

Service Manual
GX-A422SI
Power Amplifier
Released Global Quality 2015 Harman Consumer Group, Inc. Rev 1.0, 03/2015
8500 Balboa Boulevard
Northridge, California 91329
OWNER’S MANUAL 2
SCHEMATICS DIAGRAMS 18
LAYOUT DIAGRAMS 22
SET BLOCK DIAGRAM 16 PACKAGING INSTRUCTIONS 27
CONTENTS
SET WIRING DIAGRAM 17 MECHANICAL EXPLODED VIEW 26

GX-A422SI
power amplifier
OWNER'S MANUAL

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INTRODUCTION
THANK YOU for purchasing a JBL®GX-A422SI amplifier. So we can better serve you should you require warranty service, please retain your original
sales receipt and register your amplifier online at www.jbl.com.
INCLUDED ITEMS
GX-A422SI Amplifier (x 1) Speaker-level input harness
LOCATION AND MOUNTING
Although these instructions explain how to install the GX-A422SI in a general sense, they do not show specific installation methods that may be
required for your particular vehicle. If you do not have the necessary tools or experience, do not attempt the installation yourself. Instead, please ask
your authorized JBL car audio dealer about professional installation.
INSTALLATION WARNINGS AND TIPS
IMPORTANT: Disconnect the vehicle’s negative (–) battery terminal before beginning the installation.
• Always wear protective eyewear when using tools.
• Check clearances on both sides of a planned mounting surface. Be sure that screws or wires will not puncture brake lines, fuel lines or wiring
harnesses, and that wire routing will not interfere with the safe operation of the vehicle.
• When making electrical connections, make sure they are secure and properly insulated.
• If you must replace any of the amplifier's fuses, be sure to use the same type of fuse and current rating as that of the original.

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INSTALLATION LOCATION
Amplifiers need air circulation to stay cool. Select a location that provides enough air for the amp to cool itself.
• Suitable locations are under a seat (provided the amplifier doesn’t interfere with the seat adjustment mechanism), in the trunk, or in any other
location that provides enough cooling air.
• Do not mount the amplifier with the heatsink facing downward, as this interferes with the amplifier’s convection cooling.
• Mount the amplifier so that it will not be damaged by the feet of backseat passengers or shifting cargo in the trunk.
• Mount the amplifier so that it remains dry – never mount an amplifier outside the car or in the engine compartment.
MOUNTING THE AMPLIFIER
NOTE : You may find it more convenient to make all of the connections to the amplifier before you permanently mount it to the vehicle.
1. Select a suitable mounting location as described above.
2. Using the amplifier as a template, mark the locations of the mounting holes on the mounting surface.
3. Drill pilot holes in the mounting surface.
4. Attach the amplifier to the mounting surface with four appropriate mounting screws of your own choice. We suggest using #8 Phillips-head sheet
metal screws. Make sure the amplifier is mounted securely.

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POWER AND GROUND CONNECTIONS
IMPORTANT: Disconnect the vehicle's negative (–) battery terminal before beginning the installation.
The GX A422SI amplifier is capable of delivering high power levels, and requires a heavy-duty and reliable connection to the vehicle’s electrical
system to achieve optimal performance. Please adhere to the following instructions carefully.
USING THE CONNECTORS
the GX-A422SI uses the same type of screw terminals for power and speaker connections. This type of terminal is easy to use and allows the easy
connection of large-gauge wire.
To use the connectors, use a Phillips screwdriver to loosen the connector’s set screw, insert the bare wire and tighten the set screw to secure the
wire in the connector, as shown in the illustration below.
Tighten
Screw
Loosen
Screw
Insert Wire
Under Washer
IMPORTANT: Make sure the (+) and (–) speaker bare wires do not touch each other or the other terminal at both the amplifier terminals and speaker
terminals. Touching wires can cause a short circuit that can damage the amplifier.

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GROUND (GND) CONNECTION
Connect a wire (minimum 10AWG – 5.3mm2)
from the amplifier’s GND terminal directly to a
solid point on the vehicle’s chassis.
• For a good connection, use sandpaper to
clear the paint from the metal surface at this
chassis location. Use a star-type lock washer
to secure the wire’s connection.
POWER (12V) CONNECTION
1. Connect a wire (minimum 10AWG –
5.3mm2) directly to the battery’s positive (+)
terminal.
2. Install a fuse holder for a 20A fuse on this
wire within 18" (46cm) of the battery’s (+)
terminal. Do not install the fuse in the holder
at this time.
3. Route this wire to the amplifier’s location
and connect it to the amplifier’s +12V
terminal. Be sure to use appropriate
grommets whenever routing wires
through the firewall or other sheet metal.
IMPORTANT: Failure to adequately protect
the positive wire from potential damage may
result in a vehicle fire.
4. When you are finished routing and
connecting this wire, install the 20A fuse in
the holder you installed near the battery.
Power
Connectors
Audio System
Head Unit
Chassis Ground
(bare metal)
20A Fuse 18" (46cm)
Remote Turn-On
(optional)
>#18AWG (0.82mm2) Wire
>#10AWG (5.26mm2) Wire
>#10AWG (5.26mm2) Wire

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SPEAKER AND INPUT CONNECTIONS
Always connect the (+) speaker terminal on the amplifier to the (+) terminal on the speaker and the (–) speaker terminal on the amplifier to the (–) terminal
on the speaker.
IMPORTANT: Make sure the (+) and (–) bare wires do not touch each other or the other terminal at both the amplifier terminals and speaker
terminals. Touching wires can cause a short circuit that can damage the amplifier.
SPEAKER CONNECTIONS
Minimum speaker impedance: 2 ohms (each)
Connect the left and right speakers to the L and R (+) and (–) terminals.
Left Speaker Right Speaker

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INPUT CONNECTIONS
Connect your source unit or processor's line outputs as shown in the illustration below.
L+L–R–R+
Source Unit
Line Outputs
See Set The Crossover Controls, on page 10, for information about setting the amplifier's controls.
USING THE SPEAKER-LEVEL INPUTS
If your source unit doesn't have line-level outputs you can use the included speaker-level input harness to connect
the amplifier to the source unit's speaker outputs. From left to right, the conductors are: L+, L–, R–, R+ (see the
illustration to the right).

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SPEAKER CONNECTIONS: BRIDGED OPERATION
Bridged operation provides a single high-power channel for a subwoofer
Minimum speaker impedance: 4 ohms
Connect the subwoofer to the RL (+) and RR (–) terminals.) NOTE: You can connect two 2-ohm subwoofers in series to maintain the required 4-ohm
impedance for bridged operation.
Subwoofer

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INPUT CONNECTIONS: BRIDGED OPERATION
Connect your source unit or processor's subwoofer line output to the amplifier's left input, as shown in the illustration below.
NOTE: Use a "Y"-adapter to connect the source unit to the amplifier's left and right input jacks.
L+L–R–R+
Source Unit
"Y"-Adapter Subwoofer
Output
See Set The Crossover Controls, on page 10, for information about setting the amplifier's controls for bridged operation.
To use the speaker-level inputs instead of the line-level inputs, see Using The Speaker-Level Inputs, on page 7.