JL Audio M500/3 Owner's Manual

OWNER’S MANUAL

500W Marine 3-Channel Amplier

Thank you for purchasing a JL Audio amplifier for

your marine sound system.

Your amplifier has been designed and manufactured to exacting

standards in order to ensure years of musical enjoyment in your vessel.

For maximum performance, we highly recommend that you have

your new amplifier installed by an authorized JL Audio dealer. Your

authorized dealer has the training, expertise and installation equipment

to ensure optimum performance from this product. Should you

decide to install the amplifier yourself, please take the time

to read this manual thoroughly so as to familiarize yourself

with its installation requirements and setup procedures.

If you have any questions regarding the instructions in this

manual or any aspect of your amplifier’s operation, please contact your

authorized JL Audio dealer for assistance. If you need further assistance,

please call the JL Audio Technical Support Department

at [phone] during business hours.

PROTECT YOUR HEARING!

We value you as a long-term customer. For
that reason, we urge you to practice restraint in
the operation of this product so as not to damage
your hearing and that of others in your vessel.
Studies have shown that continuous exposure to
high sound pressure levels can lead to permanent
(irreparable) hearing loss. This and all other
high-power amplifiers are capable of producing
such high sound pressure levels when connected
to a speaker system. Please limit your continuous
exposure to high volume levels.

While driving, operate your audio system in
a manner that still allows you to hear necessary
noises to operate your vessel safely (horns,
sirens, etc.).

SERIAL NUMBER

In the event that your amplifier requires
service or is ever stolen, you will need to have
a record of the product’s serial number. Please
take the time to enter that number in the space
provided below. The serial number can be found
on the bottom panel of the amplifier and on the
amplifier packaging.

Serial Number:

INSTALLATION APPLICATIONS

This amplifier is designed for operation in
vessels with 12 volt, negative-ground electrical
systems. Use of this product in vessels with
positive ground and/or voltages other than 12V
may result in damage to the product and will void
th e w arra nty.

This product is not certified or approved for
use in aircraft.

Do not attempt to “ bridge” the outputs of this
amplifier with the outputs of a second amplifier,
including an identical one.

2 | JL Audio - M500/3 Owner’s Manual

Input

Mode
Switch
(pg. 7)

Preout

Selector

(pg. 7)

Remote

Level Mode

Switch
(pg. 9)

(pg. 11)

Status

LED

Ch. 1 & 2

Filter Mode

Selection

(pg. 8)

Ch. 1 & 2 Filter

Frequency

Ch. 1 & 2 Input

Sensitivity Control

(pg. 7)

Selector

(pg. 8)

Sub. Ch.

Filter Mode

Selection

(pg. 8)

Sub. Ch. Input

Sensitivity Control

(pg. 7)

Sub. Ch. Input

Sensitivity Control

(pg. 7)

PLANNING YOUR INSTALLATION

It is important that you take the time to read
this manual and that you plan out your
installation carefully. The following are some
considerations that you must take into account
when planning your installation.

Cooling Efficiency Considerations:

The outer shell of your JL Audio amplifier is
designed to remove heat from the amplifier
circuitry. For optimum cooling performance, this
outer shell should be exposed to as large a volume
of air as possible. Enclosing the amplifier in a
small, poorly ventilated chamber can lead to
excessive heat build-up and degraded
performance. If an installation calls for an
enclosure around the amplifier, we recommend
that this enclosure be ventilated with the aid
of a fan. In normal applications, fan-cooling
is not necessary.

Mounting the amplifier upside down is
strongly discouraged.

Safety Considerations:

Your amplifier needs to be installed in a dry,
well-ventilated environment and in a manner
which does not interfere with your vessel’s factory
installed electronic devices. You should also take
the time to securely mount the amplifier using the
supplied screws so that it does not come loose in
the event of a collision or a sudden jolt to the vessel.

Stupid Mistakes to Avoid:

• Check before drilling any holes in your vessel to

make sure that you will not be drilling through
the hull, a fuel tank, fuel line, wiring harness or
other vital vessel system.

• Do not run system wiring outside or underneath

the vessel. This is an extremely dangerous
practice which can result in severe damage to
your vessel and person.

• Protect all system wires from sharp edges

(metal, fiberglass, etc.) by carefully routing
them, tying them down and using grommets
and loom where appropriate.

• Do not mount the amplifier in the engine

compartment or in any other area that will
expose the amplifier circuitry to the elements.

Chassis Ground

Connector

(pg. 5)

+12 V Power

Connector

(pg. 5)

+12 VDC Ground Remote

Remote Turn-On

Connector

(pg. 6)

Channels 1 & 2

Preamp Input Jacks

(pg. 7)

Subwoofer Ch.

Preamp Input Jacks

(L)

(R)

CH. 1& 2 SUB CH. Preouts

INPUT SECTION

(pg. 7)

Preout

Jacks

(pg. 7)

While this amplifier is specially designed
for marine applications, it is not waterproof
and it should not be mounted where it is
likely to get wet.

Jack for
Remote Level
Control Knob

(pg. 9)

Remote

Level

Control

Channels 1 & 2

Speaker Outputs

(pg. 10)

CH. 1

CH. 2

(L)

(R)

Bridged Mono Subwoofer Output

Subwoofer Outputs

Mono

(pg. 10)

3

PRODUCT DESCRIPTION

The JL Audio M500/3 is a three-channel,
system amplifier utilizing JL Audio NexD™ ultra­high speed switching technology for its two main
channels and NexD™ high-speed switching for
its subwoofer channel. The NexD™ technologies
deliver outstanding fidelity and efficiency.

The M500/3 can be operated with a wide
variety of source units and system configurations.

TYPICAL INSTALLATION SEQUENCE

The following represents the sequence
for a typical amplifier installation, using
an aftermarket source unit. Additional
steps and different procedures may be
required in some applications. If you
have any questions, please contact your
authorized JL Audio dealer for assistance.

1) Disconnect the negative battery post

connection and secure the disconnected cable
to prevent accidental re-connection during
installation. This step is not optional.

2) Run 4 AWG power wire from the batter y

location to the amplifier mounting location.
Take care to route the wire in such a way that
it will not be damaged and will not interfere
with vessel operation. Use 2 AWG or larger
power wire and a power distribution block if
additional amplifiers are being installed with
the M500/3.

3) Connect power wire to the positive battery

post. Fuse the wire with an appropriate fuse
block (and connectors) within 18 inches (45
cm) wire length of the positive battery post.

This fuse is essential to protect the vessel. Do
not install the fuse until the power wire has
been securely connected to the amplifier.

4) Connect negative power wire to the negative

battery post. Use the same size power
wire as the wire connected to the “+12V ”
connection (minimum 4 AWG).

5) Run signal cables and remote turn-on wire

from the source unit to the amplifier
mounting location.

6) Run speaker cables from the speaker systems

to the amplifier mounting location.

7) Securely mount the amplifier.

8) Connect the positive and negative power

wires to the amplifier. A fuse near the
amplifier is not necessary if the M500/3 is the
only device being run from the fused main
power wire. If the fused main power wire is
shared by the M500/3 and other amplifiers
or devices, fuse each amplifier/device
within 12 inches (30 cm) of wire length,
via a fused distribution block or multiple
individual fuse blocks/on-board fuses.

9) Connect the remote turn-on wire

to the amplifier.

10) Connect the input cables to the amplifier.

11) Connect the speaker cables to the amplifier.

12) Carefully review the amplifier’s control

settings to make sure that they are set
according to the needs of the system.

13) Install the power wire fuse(s) (50A for a

single M500/3) and reconnect the negative
battery post terminal.

14) Turn on the source unit at a low level

to double-check that the amplifier is
configured correctly. Resist the temptation
to crank it up until you have verified the
control settings.

15) Make necessary adjustments to the input

sensitivity controls to obtain the right
overall output and the desired balance
in the system. See Appendix A (page 14)
for the recommended input sensitivity
setting method.

16) Enjoy the fruits of your labor with your

favorite music.

4 | JL Audio - M500/3 Owner’s Manual

POWER CONNECTIONS

INPUT SECTION

Remote

Level

Control

CH. 1& 2 SUB CH. Preouts

CH. 1

(L)

CH. 2

(R)

Bridged Mono Subwoofer Output

IMPORTANT

!

Before installing the amplifier, disconnect the
negative (ground) wire from the vessel’s battery.
This will prevent accidental damage to the system,
the vessel and your body during installation.

The ground connection should be made using

the same gauge wire as the power connection.

Any wires run through barriers must
be protected with a high quality rubber
grommet to prevent damage to the
insulation of the wire. Failure to do so
may result in a dangerous short circuit.

(L)

+12 VDC Ground Remote

(R)

The M500/3’s “+12 V DC” and “Ground”

connections are designed to accept 4 AWG
power wire. 4 AWG is the required wire size for

this amplifier.

If you are installing the M500/3 with other
amplifiers and wish to use a single main power
wire, use 2 AWG or 1/0 AWG main power wire
(depending on the overall current demands of all
the amplifiers in the system). This large power
wire should terminate into a fused distribution
block mounted as close to the amplifiers as
possible (within 12 inches / 30cm of wire length).
The fused output of the distribution block will
connect to the M500/3 with 4 AWG power wire.

JL Audio ECS fused distribution blocks are

recommended (XD-FDBU-2 and X D-FDBU-4)

Note: Smaller AWG numbers mean bigger
wire and vice-versa (1/0 AWG is the largest, 2
AWG is smaller, then 4 AWG, then 8 AWG, etc.).

Many vessels employ small (10 AWG -
6 AWG) wire to ground the battery to the vessel
chassis and to connect the alternator's positive
connection to the battery. To prevent voltage
drops, these wires should be upgraded to 4
AWG when installing amplifier systems with
main fuse ratings above 60A.

FUSE REQUIREMENTS

It is absolutely vital that the main power
wire(s) to the amplifier(s) in the system be
fused within 18 inches (45 cm) of the positive
battery post connection. The fuse value at each
power wire should be high enough for all of the
equipment being run from that power wire. If
only the M500/3 is being run from that power
wire, we recommend a 50A fuse be used.

If fusing the amplif ier near its power
connections (when more than one amp is being
run from the main power wire), use a 50A fuse.
MAXI™ plastic-body fuses are recommended.

To connect the power wires to the amplifier,
first back out the set screw on the top of the
terminal block, using the supplied 2.5 mm hex
wrench. Strip 1/2 inch (12 mm) of insulation from
the end of each wire and insert the bare wire into
the terminal block, seating it firmly so that no
bare wire is exposed. While holding the wire in
place, tighten the set screw firmly, taking care not
to strip the head of the screw and making sure
that the wire (not the insulation) is firmly gripped
by the wire clamp in the terminal.

5

TURNON LEAD

INPUT SECTION

Remote

Level

Control

CH. 1& 2 SUB CH. Preouts

CH. 1

(L)

CH. 2

(R)

Bridged Mono Subwoofer Output

Remote

Level

Control

CH. 1

(L)

CH. 2

(R)

Bridged Mono Subwoofer Output

The M500/3 uses a conventional +12V remote
turn-on lead, typically controlled by the source
unit's remote turn-on output. The amplifier will
turn on when +12V is present at its “Remote”
input and turn off when +12V is switched off. If
a source unit does not have a dedicated remote
turn-on output, the amplifier’s turn-on lead can
be connected to +12V via a switch that derives
power from an ignition-switched circuit.

The M500/3’s “Remote” turn-on connector is
designed to accept 18 AWG – 12 AWG wire. To
connect the remote turn-on wire to the amplifier,
first back out the set screw on the top of the
terminal block, using the supplied 2.5mm hex
wrench. Strip 1/2 inch (12mm) of wire and insert
the bare wire into the terminal block, seating it
firmly so that no bare wire is exposed. While
holding the wire in the terminal, tighten the set
screw firmly, taking care not to strip the head of
the screw and making sure that the wire (not the
insulation) is firmly gripped by the wire clamp in
the terminal.

(L)

+12 VDC Ground Remote

(R)

INPUT SECTION

The M500/3’s input section allows you to send
signals to the amplif ier section through the use
of two or four differential-balanced inputs.

Input connections are via one or two pairs of

traditional RCA-type jacks.

(L)

(R)

Remote

CH. 1& 2 SUB CH. Preouts

INPUT SECTION

If you wish to send four discrete channels into
the M500/3, simply use all four inputs and set the
“Input Mode” switch in the “4 Ch.” position. The

amplifier will automatically combine the Sub Ch.

input signals to mono.

You may also choose to apply only two
channels of input to deliver signal to all three
amplifier channels. To do this, set the “Input
Mode” switch to “2 Ch.” and use only the
inputs to channels 1 & 2. The amplifier will

automatically combine the Ch. 1 & 2 input
signals to mono for the Subwoofer Channel.

6 | JL Audio - M500/3 Owner’s Manual