JBL 500GTi, 400GTi manual Case of Difficulty, 800-336-4JBL 4525 between 9AM and 5PM eastern time

to tweeter transition. Set the high crossover frequency at or above 5kHz if a 12dB per octave crossover is used and at or above 3.5kHz if you are using an 18 or 24dB per octave crossover. For safety, the maximum recommended amplifier power routed directly to the 400 and 500GTi Midrange is 150 watts for the 400GTi and 200 watts for the 500GTi.

A Note on Power Handling

As a result of their high efficiency, all JBL loudspeakers will produce reasonable volume levels in the automotive environment using very little amplifier power. However, the use of a low-powered amplifier to attain very high volume levels could lead to overdriving the amplifier. This will generate high distortion levels which can easily damage loudspeakers, even if the rated power of the amplifier is below the rated maximum power handling of the loudspeaker!

As a general rule, do not turn up the volume control past the point where you hear distortion in the form of either signal distortion from an overdriven amplifier or mechanical noise from an overstressed speaker. For the

best performance and system reliability, you should select an amplifier with an output rating greater than the maximum power likely to be used to generate the desired volume levels. If you want your system “Loud + Clear,” we suggest that you step up to a JBL power amplifier which has an RMS power rating equal to, but not exceeding, the Maximum Recommended Amplifier Power listed in the specifications of your specific JBL speaker. This margin of reserve power will ensure that the amplifier will not attempt to deliver more power than it’s design allows. Your dealer will be happy to point out which high power JBL amplifiers are optimum for your application and listening habits.

Following these guidelines will provide virtually distortion free sound reproduction and long loudspeaker life.

In Case of Difficulty

The most common difficulties are noise, distortion, and intermittent connections.

System noise is usually not the fault of the 400 and 500GTi. Hiss or “alternator whine” is most often the result of faulty grounding of the system electronics or

improper setting of amplifier level controls. An exception to this is if the passive crossover components are mounted near a source of radiated noise, the network may pick-up this noise with sufficient power to drive the 400 and 500GTi. For this reason, be careful not to mount any passive crossover components near wires carrying high currents such as battery cables or wires leading to ammeters or tachometers.

Distortion is usually the result of overdriving one or more components in the system. The problem is most likely insufficient amplifier power, or improper setting of gain controls. Refer to the instructions which came with the electronics for assistance. The 400 and 500GTi will not play as loudly, or handle the full rated power, when used without a high-pass crossover. When using the 400 or 500GTi full-range, be careful to limit the volume level to that which can be reproduced without audible distortion from the speaker.

If you want to talk to us about any problems, call JBL Customer Service at

1-800-336-4JBL (4525) between 9AM and 5PM eastern time.

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