400/600 MANUAL.QXP 7/17/98 11:10 AM Page 9
to tweeter transition. Set the high crossoverbest performance and system reliabilityimproper setting of amplifier level controls. , youAn
frequency at or above 5kHz if a 12dB pershould select an amplifier with an output ratingexception to this is if the passive crossover
octave crossover is used and at or abovegreater than the maximum power likely to becomponents are mounted near a source of
3.5kHz if you are using an 18 or 24dB perused to generate the desired volume levels. Ifradiated noise, the network may pick-up this
octave crossover. For safety, the maximumyou want your system OLoud + Clear,�noise with suf weficient power to drive the 400
recommended amplifier power routedsuggest that you step up to a JBL powerand 500GTi. For this reason, be careful not to
directly to the 400 and 500GTi Midrange isamplifier which has an RMS power ratingmount any passive crossover components
150 watts for the 400GTi and 200 watts forequal to, but not exceeding, the Maximumnear wires carrying high currents such as
the 500GTi.Recommended Amplifier Powerlisted in thebattery cables or wires leading to ammeters
specifications of your specific JBL speakeror tachometers..
A Note on Power HandlingThis margin of reserve power will ensure thatDistortion is usually the result of
As a result of their high efficiency, allthe amplifier will not attempt to deliver moreoverdriving one or more components in the
power than itOs design allows. Your dealer willsystem. The problem is most likely insufficient
JBL loudspeakers will produce reasonablebe happy to point out which high power JBLamplifier power, or improper setting of gain
volume levels in the automotive environmentamplifiers are optimum for your applicationcontrols. Refer to the instructions which came
using very little amplifier power. However, the
use of a low-powered amplifier to attain veryand listening habits.with the electronics for assistance. The 400
high volume levels could lead to overdrivingFollowing these guidelines will provideand 500GTi will not play as loudly, or handle
virtually distortion free sound reproduction andthe full rated power, when used without a
the amplifier. This will generate highlong loudspeaker life.high-pass crossover. When using the 400 or
distortion levels which can easily damage500GTi full-range, be careful to limit the
loudspeakers, even if the rated power of the
amplifier is below the rated maximum powerIn Case of Difficultyvolume level to that which can be reproduced
handling of the loudspeaker!The most common difficulties are noise,without audible distortion from the speaker.
As a general rule, do not turn up thedistortion, and intermittent connections.If you want to talk to us about any
problems, call JBL Customer Service at
volume control past the point where you hearSystem noise is usually not the fault of1-800-336-4JBL (4525) between 9AM and
distortion in the form of either signal distortionthe 400 and 500GTi. Hiss or Oalternator
from an overdriven amplifier or mechanicalwhine� is most often the result of faulty5PM eastern time.
noise from an overstressed speakerFor the. grounding of the system electronics or
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