Crossover Tweeter
Level Adjustment
The GTi system crossover allows you
to adjust the level of the GTi systems
tweeter. This adjustment is located under
the crossover cover. To remove this cover
simply press on the end of the cover
(as shown in Figure G) and lift off. The
adjustment of the tweeter level is done by
setting the switch on the crossover (see
Figure H) to the “0dB”, “–2dB” or “–4dB”
position. Set this switch in the position that
matches you personal preference. Both
crossovers should have this switch set in
the same position.
Speaker Break-In
The 404 and 504GTi woofer/
midranges use many high strength
materials which require benefit from a
break-in period before they will achieve top
performance. After a break-in period of
about 1-hour at moderate volume the
drivers will achieve peak performance.
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 its design allows.
Your dealer will be happy to point out
which high power JBL amplifiers are
12
LIFT
PRESS
OdB
–2dB
–4dB
Figure G
Figure H
404/504 MANUAL.QXP 7/17/98 11:39 AM Page 12
