GX-A604/GX-A602/GX-A3001 power amplifier OWNER'S MANUAL
INTRODUCTION THANK YOU for purchasing a JBL® GX-series 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.
English 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.
POWER AND GROUND CONNECTIONS IMPORTANT: Disconnect the vehicle's negative (–) battery terminal before beginning the installation. The GX series amplifiers are capable of delivering high power levels, and require 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 GX-series amplifiers use the same type of screw terminals for power and speaker connections.
English GROUND (GND) CONNECTION Power Connectors 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. Audio System Head Unit >#18AWG (0.
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.
English GX-A604 INPUT CONNECTIONS: 4-CHANNEL OPERATION Connect your source unit or processor's front and rear left and right outputs to the amplifier's inputs as shown in the illustration. Source Unit Front Line Outputs Rear Line Outputs See Set The Crossover Controls, on page 11, for information about setting the amplifier's controls for 4-channel operation. To use the speaker-level inputs instead of the line-level inputs, see Using The Speaker-Level Inputs, on page 12. www.jbl.
GX-A604 SPEAKER CONNECTIONS: 3-CHANNEL OPERATION Minimum speaker impedance: 2 ohms each (left & right speakers); 4 ohms (subwoofer) • Connect the left and right speakers to the FL and FR (+) and (–) terminals • Connect the subwoofer to the RL (+) and RR (–) terminals. (The rear-channel Bass Boost control makes the rear channels preferable for subwoofer connection. See Set The Bass Boost, on page 12.
English GX-A604 INPUT CONNECTIONS: 3-CHANNEL OPERATION Connect your source unit or processor's line outputs as shown in the illustration below. Set the input mode switch in the "4CH" position NOTE: Use a "Y"-adapter to connect the source unit's subwoofer output to the amplifier's rear left and right input jacks. "Y"-Adapter Source Unit Front Line Outputs Subwoofer Line Output See Set The Crossover Controls, on page 11, for information about setting the amplifier's controls for 3-channel operation.
GX-A604 SPEAKER CONNECTIONS: 2-CHANNEL OPERATION Minimum speaker impedance: 4 ohms (each) Connect the left and right speakers as shown in the illustration below.
English GX-A604 INPUT CONNECTIONS: 2-CHANNEL OPERATION Connect your source unit or processor's line outputs as shown in the illustration below. Use only the front left and right input connections and make sure that the Input Mode switch is set in the "2CH" position. Source Unit Front Line Outputs See Set The Crossover Controls, on page 11, for information about setting the amplifier's controls for 2-channel operation.
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). The speaker-level connectors on all GX-series amp models follow this wiring configuration. Follow the instructions in the previous sections, substituting the speaker-level connectors for the line-level connectors.
English GX-A602 INPUT CONNECTIONS: 2-CHANNEL OPERATION Connect your source unit or processor's line outputs as shown in the illustration below. L+L–R–R+ Line Outputs Source Unit See Set The Crossover Controls, on page 11, for information about setting the amplifier's controls for 2-channel operation. To use the speaker level inputs instead of the line-level inputs, see Using The Speaker-Level Inputs, on page 12. www.jbl.
GX-A602 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.
English GX-A602 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+ "Y"-Adapter Subwoofer Output Source Unit See Set The Crossover Controls, on page 11, for information about setting the amplifier's controls for bridged operation.
GX-A3001 SPEAKER CONNECTIONS Minimum speaker impedance; 2 ohms (single subwoofer); 4 ohms (2 subwoofers) The GX-A3001 has two parallel sets of speaker connectors, allowing you to connect two subwoofers. Fuses 20A 4-Ohm Subwoofer +12V 4-Ohm Subwoofer • If you are using a single subwoofer you can connect it to either set of GX-A3001 speaker connectors. • If you are using two 2-ohm subwoofers you can connect them to one of the sets of connectors in series to be above the required 2-ohm minimum impedance.
English GX-A3001 INPUT CONNECTION Use a "Y"-adapter to connect your source unit or processor's subwoofer line output to the amplifier's left and right inputs, as shown in the illustration below. If your source unit does not have a dedicated subwoofer output you can connect the rear left/right outputs to the amplifier's left and right inputs. L+L–R–R+ "Y"-Adapter Subwoofer Output Source Unit See Set The Crossover Controls, on page 11, for information about setting the amplifier's controls.
CONTROLS, INPUT CONNECTIONS AND INDICATORS GX-A604 Power Indicator Front Crossover Filter Switch 18 Input Mode Switch Front Level Control Front Speaker-Level Input Connector Rear Line-Level Input Connectors Front Line-Level Input Connectors Rear Speaker-Level Input Connector Rear Level Control Rear Crossover Control Rear Crossover Filter Switch Bass Boost Switch Protection Indicator
English GX-A602 L+L–R–R+ Line-level Input Connectors Speaker-Level Input Connector Crossover Filter Switch Level Control Bass Boost Switch Protection Indicator Power Indicator GX-A3001 L+L–R–R+ Line-Level Input Connectors Speaker-Level Input Connector Level Control Crossover Bass Boost Control Control Protection Indicator Power Indicator www.jbl.
SET THE CROSSOVER CONTROLS GX-A604: 4-CHANNEL OPERATION Input Mode switch: Set the Input Mode switch in the "4CH" position. Front Crossover Filter switch: Set the Front Crossover Filter switch in the “ON” (high-pass) position. This will limit the amount of low-frequency energy sent to the speakers, significantly reducing distortion and preventing the speakers from damage.
English Rear Crossover control: The Rear Crossover control setting you use for subwoofers will depend on the type and location of your system’s subwoofer. Start by setting the Rear Crossover control to a frequency somewhat lower than the 80Hz setting on the front channels.
GX-A602: 2-CHANNEL OPERATION Crossover Filter switch: • If you have connected the amplifier to a pair of 6" or smaller full-range speakers, set the Crossover Filter switch in the “HP” (high-pass) position. This will limit the amount of low-frequency energy sent to the speakers, significantly reducing distortion and preventing the speakers from damage.
English SET THE BASS BOOST GX-A604: When you’re using the amplifier’s rear channels to power a subwoofer, the Bass Boost switch can provide 12dB of bass boost at 45Hz. (The switch only affects the amplifier's rear channels.) Set this switch according to your personal taste, but if using it causes audible distortion or bottoming of your subwoofer we recommend setting it to "OFF." CAUTION: Only use the Bass Boost switch if you’ve configured the rear channels to power a subwoofer.
TROUBLESHOOTING If your amplifier isn't performing the way you think is should, check to see if the problem is covered in this section before calling your dealer or contacting JBL customer service. PROBLEM CAUSES AND SOLUTIONS No sound (the amplifier's Power LED is off) • Check that the amplifier's +12V and GND connections have been properly made. • Check if the fuse on the +12V wire located near the battery is blown: If so, replace it with an identical fuse.
English PROBLEM CAUSES AND SOLUTIONS Sound only comes from some of the speakers connected to the amplifier • Check that the vehicle audio system's source unit's balance and fader controls are set to their center (midpoint) positions.
SPECIFICATIONS 26 GX-A604 GX-A602 GX-A3001 Max power (15.5V, 1kHz, 10%THD, total ch, 2 ohms) 435W 280W 415W (15.
English www.jbl.
HARMAN International Industries, Incorporated 8500 Balboa Boulevard, Northridge, CA 91329 USA © 2013 HARMAN International Industries, Incorporated. All rights reserved. JBL is a trademark of HARMAN International Industries, Incorporated, registered in the United States and/or other countries. All Rights Reserved. Features, specifications and appearance are subject to change without notice. Part No. 20130624 Rev: A www.jbl.
