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5.

Connect the speaker wire from the
crossover terminals marked “W” to the
woofer/midrange terminals of the
speaker by either soldering (preferred)
or using crimp terminals. Connect the
“+W” terminal of the crossover to the
orange “W” terminal of the speaker.
Repeat for “–W” terminal.

6.

Attach the foam gasket to the back of
the woofer/midrange. Connect the
speaker wire from the crossover
terminals marked “ T ” to the tweeter
terminals of the speaker by either
soldering (preferred) or using crimp
terminals. The “+T” terminal of the
crossover should be connected to the
orange colored T terminal on the
speaker.

7.

Mount the speaker to the hole location
using three #8 x 1

1

/

4

" screws as shown

in Figure D.

8.

Push the grille down onto the speaker,
making sure the tabs on the speaker,
match with the slots in the grille. Twist
the grille about 

1

/

2

" (12mm) clockwise to

lock the grille into place.

Note: The metal grille is designed so

that it can be covered with grille cloth if
desired. Simply, remove the metal grille
from the plastic trim ring as shown in
Figure E. Then use spray adhesive to glue
and wrap the grille cloth to the metal grille.
Push the metal grille with cloth back into
the grille frame. For even better interior
matching it is also possible to use plastic
compatible paint to match the grille frame
to the vehicle’s interior.

Logo Orientation on Grille

The orientation of the logo on the

grille relative to the plastic grille ring can
be adjusted. Simply remove the metal
grille and reassemble the metal grille to
the grille frame utilizing a different tab slot. 

9

Figure E

Figure D

Tab

slot

404/504 MANUAL.QXP  7/17/98 11:39 AM  Page 9

Use 2-conductor stranded type,

insulated wire to connect the 404 and
504GTi Woofer/Midrange and Tweeter to
the included crossover, and the crossover
to the amplifier as shown in Figure F.
A minimum wire gauge of 18AWG is
recommended, with larger size suggested
for wire runs longer than 10 feet.

The polarity (the positive / negative

orientation of the connections) for every
speaker and crossover to amplifier
connection must be consistent from left to
right channel to assure proper imaging and
optimum frequency response. This does
not mean that the Coupled Components

TM

should always be connected in the same
polarity as the woofer/midbass or
subwoofer however. It is possible, due 
to the difference in the distance that 
the sound travels from the Coupled
Components

™

to your ears, compared to 

the distance from the subwoofer or
woofer/midbass, and the wavelengths of
sound at the crossover frequency, that a
connection where the subwoofer or
woofer/midbass are connected in reverse
polarity from the Coupled Component

TM

drivers may actually result in better sound.
Because there is no way to accurately
predict this before installation, we
recommend that you try the connection
both ways, and leave it in the polarity that
gives the smoothest audible transition
between the Coupled Components

™

and

the subwoofer or woofer/midbass. Some 
active crossovers, such as the JBL GTX47,
have a phase switch which enables you 
to easily switch polarity. When the sub-
woofer or woofer/midbass and Coupled
Components

TM

are mounted close to each

other, the in-phase connection will usually
yield the best sound.

There are a variety of system options

available with the 404 and 504GTi. The
simplest configuration is to use the 404
and 504GTi full range. Although this will
yield good sound, the best performance
will be achieved in a high-end system
which includes subwoofers and, optionally,
midbass transducers. Because the 404
and 504GTi are specifically designed
for mid and high frequency operation,
they should have their extremely low
frequencies blocked by electrical means in
order to achieve the best system fidelity
and the widest dynamic range. However,
full range use may be obtained at slightly
lower power handling levels.

10

INPUT

WOOFER

TWEETER

504 GTI Crossover

INPUT

WOOFER

TWEETER

Figure F

404/504 MANUAL.QXP  7/17/98 11:39 AM  Page 10

For the best performance, we

recommend that an active crossover with
a minimum of 12dB per octave slope be
used for the transition point between the
Subwoofer and the 404 or 504GTi. The
optimum crossover frequency for this
transition is dependent on the specific
components used, the vehicle, and other
installation details. As a general rule, the
crossover frequency should be as low as
possible to achieve the best system
imaging. You can fine-tune the crossover
after the installation is complete for the
best sound. A good place to start your
tuning process is between 50Hz and
150Hz when using the 504GTi and
between 80Hz and 150Hz when using the
404GTi. In 4-way systems using a midbass
driver such as the 600GTi, the crossover
point may be raised higher without
detrimentally affecting imaging as long as
the woofer/midbass drivers can be
mounted reasonably close to the Coupled
Components

TM

. This higher crossover

frequency will allow the system to play
louder. Since no crossover is perfect, it is
advisable to keep your crossover points

away from the range where your hearing is
most sensitive. Therefore we recommend
that you try to keep the high-pass
frequency below 250Hz. This lets the 404
or 504GTi reproduce the entire range of
frequencies covering the most important
vocal and lead instrument fundamentals
and their harmonics.

If you prefer to use all passive

crossovers, you will need to construct
or purchase a high-pass filter for the
subwoofer to Coupled Component

TM

transition point and install it in-line ahead
of the 404 or 504GTi Crossover. For
the best system dynamic range, we
recommend that a minimum slope of 12dB
per octave be used.

The most advanced system designs

use active electronic crossovers such as
the JBL GTX2, GTX4 or GTX47 at both the
subwoofer (or woofer/midbass)-to-Coupled
Component

™

transition point and at the

woofer/midrange-to-tweeter transition. This
is possible with the coupled component
system because the tweeter and
woofer/midrange are accessible separately
through the individual sets of terminals.

Set the high crossover frequency at or
above 5kHz if a 12dB per octave
crossover is used and at or above 4.5kHz
if you are using an 18 or 24dB per octave
crossover. In this configuration, the
crossovers supplied with the 404 and
504GTi are not used. For tweeter
protection, a 1.5A fast acting fuse should
be installed in series with the tweeter.
The maximum recommended RMS
amplifier power routed directly to the
woofer/midbass driver is 125 watts for the
404GTi and 150 watts for the 504GTi.
When used with the appropriate crossover
and fused as recommended above, the
tweeter can be connected to amplifier
channels of the same power rating
although there is little point in using an
amplifier in excess of 50 watts when
driving the tweeter alone.

11

404/504 MANUAL.QXP  7/17/98 11:39 AM  Page 11

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.

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.

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