Case of Difﬁculty, Power-on light does not come on

8. In Case of Difﬁculty

Power-on light does not come on

•Head unit not on; turn the head unit on.

•Ground wire is disconnected or defec- tive; check for continuity with an ohm- meter between the ampliﬁer’s ground ter- minal and a known chassis ground point.

•Battery wire is disconnected or defec- tive; check for approximately +12 volts between the ampliﬁer’s battery and ground terminals.

•Blown fuse; check ampliﬁer’s fuses located on the end panel near the power connector. If they are blown, replace them with identical ones. If the new fuses blow immediately, check all the wiring connec- tions. If the source of the problem cannot be determined, consult your JBL dealer.

•Remote-on wire between the head unit and the ampliﬁers is disconnected or defective; check for +12 volts between ampliﬁer's remote-on input terminal and the ground wire with the head unit on.

Power light is on, but no sound is heard from some or all of the speakers

•Incorrect switch settings; make sure that all switches (mode, input and crossover) are in their correct positions for your sys- tem conﬁguration.

•Incorrectly connected or shorted speaker wires; check for shorts in wiring.

•Defective or disconnected audio cables; check for continuity and replace if necessary.

•Incorrect gain adjustment; verify that the ampliﬁer gain controls are not turned completely down. If they are, sound out- put level may be very low and may give the impression that the system (or part of the system) is dead.

Power light is on, but no sound is heard from some or all of the speakers

•Defective head unit or signal processor; check each component for proper wiring and operation.

•Defective GTQ ampliﬁer; if there is audio signal present at the inputs of the ampliﬁ- er and there is no output, the GTQ ampliﬁ- er may be defective.

Alternator whine through the audio sys- tem with the engine running

•Ground loops; follow the wiring sugges- tions in the section called “Solving Noise Problems.” Also, verify that the chassis grounding point you have chosen is true ground by checking for continuity between the chassis ground point and battery ground.

Bass output from speakers too low

•Speaker wired out of phase; check for proper polarity on all speaker wiring (+ amp terminal to + speaker terminal and – amp terminal to – speaker terminal).

Power light is blinking and no sound is heard

•Incorrectly connected or shorted speaker wires; check for shorts in wiring.

•Defective GTQ ampliﬁer; if there is no short on the speaker outputs, the GTQ ampliﬁer may be broken. Consult your JBL dealer.

GTQ240, GTQ360 specifications

The JBL GTQ360 and GTQ240 are part of JBL's esteemed lineup of car audio systems, designed to deliver unparalleled sound quality while ensuring robust performance tailored for automotive environments. Both models stand out for their blend of advanced technology, durable construction, and user-friendly features.

The JBL GTQ360 boasts a peak power handling of 360 watts, making it a powerhouse in sound output. This model is equipped with a 12-inch subwoofer that utilizes a high-strength polypropylene cone, allowing for deep bass response and clarity across a range of frequencies. The GTQ360 also features an oversize voice coil that enhances thermal dissipation, promoting longevity and consistent performance even during extended listening sessions.

On the other hand, the GTQ240 is slightly more compact, with a peak power handling of 240 watts. This model features a 10-inch subwoofer, designed for those who prefer a smaller footprint without sacrificing sound quality. Like its larger counterpart, the GTQ240 utilizes a durable polypropylene cone, providing durability alongside exceptional sound reproduction. Its efficient voice coil design also ensures that users enjoy a rich audio experience without unwanted distortion.

Both models employ JBL's signature technologies, including a low-pass crossover that allows users to fine-tune the subwoofer's output according to their preferences and the acoustic characteristics of their vehicle. This capability means that whether you’re a fan of thumping bass or more subtle low-end frequencies, these subwoofers can accommodate your taste.

Installation is straightforward, thanks to the user-centric design of both the GTQ360 and GTQ240. They come with adjustable mounting options and provisions that enable easy integration into various vehicle types. The construction of both subwoofers is robust, featuring a reinforced basket designed to mitigate vibration and resonance, thereby maintaining the purity of the sound produced.

In summary, the JBL GTQ360 and GTQ240 are compelling choices for car audio enthusiasts seeking superior sound quality. With their impressive power handling, innovative technologies, and durable construction, these subwoofers are set to enhance any vehicle's audio system, allowing users to enjoy their favorite music with a depth and clarity that only JBL can offer. Whether you want a powerful bass experience or a balanced sound profile, these models deliver a remarkable listening experience.