JBL Loud + Clear LC-A504 User Manual Download Page 2

Choosing a Location and Mounting the Amplifier

Amplifiers need air to stay cool. Suitable locations are under seats

(provided the amplifier doesn’t interfere with the seat-adjustment

mechanism), in the trunk or in any location that provides enough air

for the amp to cool itself. Do not mount the amplifier with the heat-sink

fins facing downward; this makes convection cooling of the amplifier

impossible.

Mount the amplifier so that it is not damaged by the feet of back-seat

passengers or shifting cargo in the trunk. Mount the amplifier so that it

remains dry – never mount an amplifier outside the car or in the engine

compartment. 

Using the amplifier as a template, mark the location of the mounting holes

on the mounting surface, drill pilot holes and attach the amplifier to the

mounting surface with screws. Make sure the amplifier is mounted securely.

Wiring the Power Connections

Refer to Figures 1–4 for connector locations. Use at least 10-gauge wire

for power and ground connections.

For power, remote and ground connections strip off one end of each

jacket to reveal bare wire for insertion into the barrier-strip connectors.

Connect a wire from the GND connector on the amplifier to the nearest

bare-metal chassis component; scrape away the paint to ensure good

conductivity. Next, connect a wire between the BATT terminal on the

amplifier and the POS (

+

) terminal of the vehicle’s battery. Pass the

wire through a factory-installed grommet in the firewall, or install a

grommet if a factory grommet is not available. You must install, within

18" of the battery connection, a fuse holder and fuse with the same    

rating as the fuse in the amplifier’s chassis. This will prevent a short

circuit from causing damage to the amplifier or the car. Connect a wire

between the REM terminal of the amplifier and the “remote out” or

power-antenna lead on the vehicle’s radio. 

Wiring the Speaker-Output Connections

Connect the speakers, observing proper polarity, to the speaker-output

barrier strip. The total impedance of the speaker system connected to the

amplifier when the amplifier is driven in stereo must be at least two ohms.

If you are bridging the amplifier, connect the speaker wires to the termi-

nals marked “bridged,” observing proper polarity. The total impedance

of the speaker system connected to the amplifier must be at least four

ohms in bridged mode.  

If you are running the amp in Tri-Mode (stereo and mono simultaneously),

connect the satellite speakers to the speaker connector as you would a

pair of stereo speakers. Connect the subwoofer to the terminals marked

“bridged.” Refer to the chart below to determine the capacitor and

inductor values you’ll need to route bass signals to the woofer, and the

midrange and high frequencies to the satellite speakers. These passive

crossover components will also ensure that the impedance of the speaker

system doesn’t drop below two ohms.

FREQUENCY

INDUCTOR

CAPACITOR

Crossover 

6dB/oct. LP

6dB/oct. HP

(4 ohm)

(4 ohm)

75Hz

8.0mH

530µF

100Hz

6.4mH

400µF

125Hz

5.0mH

318µF

150Hz

4.2mH

265µF

175Hz

3.6mH

227µF

200Hz

3.2mH

198µF

Thank you

for purchasing a

JBL Loud + Clear amplifier. In

order that we may better serve you

should you require warranty ser-

vice on your new amplifier, please

retain your original purchase

receipt and return the enclosed

warranty registration card.

Important: 

Installation of auto-

motive stereo components can

require extensive experience in

performing a variety of mechani-

cal and electrical procedures.

Although these instructions

explain, in a general sense, how

to install Loud + Clear amplifiers,

they may not show the exact

installation methods for your

particular vehicle. If you feel

you lack the tools or necessary

experience, ask your authorized

JBL car-audio dealer about profes-

sional installation options.

Installation Warnings and Tips

• Always wear protective 

eyewear when using tools.

• Turn off all audio systems and

other electrical devices before

you start. 

• Disconnect the negative (–) lead

from your vehicle’s battery.

• Check clearances on both sides

of a planned mounting surface

before drilling any holes or

installing any screws. Remember

that the screws can extend behind

the surface.

• At the installation sites, locate

and make a note of all fuel lines,

hydraulic brake lines, vacuum

lines and electrical wiring. Use

extreme caution when cutting or

drilling in and around these areas.

• Before drilling or cutting holes,

use a utility knife to remove

unwanted fabric or vinyl to keep

material from snagging in a 

drill bit.

• When routing cables, keep input-

signal cables away from power

cables and speaker wires. 

• When making connections,

ensure that they are secure and

properly insulated.

• If the amplifier’s fuse must be

replaced, use only the same type

and rating as that of the original.

Do not substitute another kind.

Warning:

Playing loud music in

an automobile can permanently

damage your hearing as well as

hinder your ability to hear traffic.

We recommend listening at low

levels while in your car. JBL

accepts no liability for hearing

loss, bodily injury or property

damage resulting from use or

misuse of this product. 

LC-Amplifier OM   3/4/99  10:55 AM  Page 3

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