Your amplifier has been designed and manufactured to exacting
standards in order to ensure years of musical enjoyment in your vehicle.
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 (954) 443-1100 during business hours.
PROTECT YOUR HEARING!
Status
LED
(pg. 11)
Filter
Frequency
Selector
(pg. 8)
LP Filter
Mode/Slope
Selection
(pg. 8)
Input Sensi tivity
Control
(pg. 7)
Infrasonic
Filter
Selection
(pg. 9)
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 vehicle.
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 vehicle 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
vehicles with 12 volt, negative-ground electrical
systems. Use of this product in vehicles with
positive ground and/or voltages other than 12V
may result in damage to the product and will void
th e w ar ran ty.
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 - XD600/1 Owner’s Manual
PLANNING YOUR INSTALLATION
Remote Turn-On
Connector
(pg. 6)
Chassis Ground
Connector
(pg. 5)
Left & Right
Preamp Input Jacks
(pg. 7)
+12 V Power
Connector
(pg. 5)
Mono
Subwoofer Outputs
(pg. 10)
Jack for
Remote Level
Control Knob
(pg. 9)
Left & Right
Preamp Ou tput Jacks
(pg. 10)
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.
If mounting the amplifier under a seat,
make sure there is at least 1 inch (2.5 cm) of
space above the amplifier’s outer shell to permit
proper cooling.
Safety Considerations:
Your amplifier needs to be installed in a dry,
well-ventilated environment and in a manner
which does not interfere with your vehicle’s safety
equipment (air bags, seat belt systems, ABS brake
systems, etc.). You should also take the time to
securely mount the amplifier so that it does not
come loose in the event of a collision or a sudden
jolt to the vehicle.
Stupid Mistakes to Avoid
• Check before drilling any holes in your vehicle
to make sure that you will not be drilling
through a gas tank, brake line, wiring harness or
other vital vehicle system.
• Do not run system wiring outside or underneath
the vehicle. This is an extremely dangerous
practice which can result in severe damage to
your vehicle and person.
• Protect all system wires from sharp metal
edges and wear by carefully routing them,
tying them down and using grommets and
loom where appropriate.
• Do not mount the amplifier in the engine
compartment, under the vehicle, on the roof
or in any other area that will expose the
amplifier circuitry to the elements.
ENGLISH
3
PRODUCT DESCRIPTION
The XD600/1 is a monoblock
amplifier utilizing JL Audio NexD™ high
speed switching technology to deliver
outstanding fidelity and efficiency.
The XD600/1 can be operated with a wide
variety of source units and system configurations.
Its frequency response is limited to the range
below 500 Hz. It is not designed for driving
midrange speakers or tweeters. Every aspect of its
operation has been optimized for low-frequency
amplification. For detailed specifications, please
refer to Appendix C (page 13).
TYPICAL INSTALLATION SEQUENCE
The following represents the sequence
for a typical amplifier installation, using an
aftermarket source unit or OEM Interface
processor (like the CleanSweep CL441dsp).
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 battery
location to the amplifier mounting location,
taking care to route it in such a way that it
will not be damaged and will not interfere
with vehicle operation. Use 4 AWG or larger
power wire and a power distribution block if
additional amplifiers are being installed with
the X D600/1.
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 vehicle.
Do not install the fuse until the power wire
has been securely connected to the amplifier.
4) Run signal cables and remote turn-on wire
from the source unit to the final amplifier
mounting location.
5) Run speaker cables from the speaker systems
to the amplifier mounting location.
6) Find a good, solid metal grounding point
close to the amplifier and connect the
negative power wire to it using appropriate
hardware (use of the JL Audio ECS master
ground lug, XB-MGLU is recommended).
Use 4 AWG wire, no longer than 36 inches
(90 cm) from the amplifier to the ground
connection point. In some vehicles, it may be
necessary to upgrade the battery ground wire.
(See page 5 for important notice).
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
XD600/1 is the only device being run
from the fused main power wire. If
the fused main power wire is shared
by the XD600/1 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 (50A for a
single XD600/1) and reconnect the negative
battery post terminal. Install the fuse (50A)
near the amplifier (if applicable).
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 12)
for the recommended input sensitivity
setting method.
16) Enjoy the fruits of your labor with your
favorite music.
4 | JL Audio - XD600/1 Owner’s Manual
POWER CONNECTIONS
Before installing the amplifier, disconnect the
negative (ground) wire from the vehicle’s battery.
This will prevent accidental damage to the system,
the vehicle and your body during installation.
The XD600/1’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 XD600/1 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 2 AWG or
1/0 AWG 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 XD600/1
with 4 AWG power wire. JL Audio ECS
fused distribution blocks are recommended
(XD-FDBU-2 and XD-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.).
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.
The ground connection should be made
using 4 AWG wire and should be kept as short
as possible, while accessing a solid piece of sheet
metal in the vehicle. The surface of the sheet
metal should be sanded at the contact point
to create a clean, metal-to-metal connection
between the chassis and the termination of
the ground wire. For optimal grounding, we
recommend the use of a JL Audio ECS master
ground lug (XB-MGLU). Alternatively, a sheet
metal screw or bolt can be used with a star
washer.
Any wires run through metal barriers (such
as firewalls), 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.
Many vehicles employ small (10 AWG -
6 AWG) wire to ground the battery to the
vehicle 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 XD600/1 is being run from that power
wire, use a 50A fuse.
If fusing the amplifier near its power
connections (when more than one amp is being
run from the main power wire), use a 50A fuse
(MAXI™ big plastic-body fuse is recommended).
ENGLISH
5
TURNON LEAD
The XD600/1 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 XD600/1’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 2.5 mm 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 is firmly
gripped by the set screw.
6 | JL Audio - XD600/1 Owner’s Manual
INPUT SECTION
The XD600/1’s input section allows
you to send signal to the amplifier section
through the use of two differentialbalanced inputs, one for the left channel
signal and one for the right channel signal.
Connection is via RCA-type jacks.
You may run a stereo or a mono signal into
the inputs of the amplifier. The amplifier’s input
section automatically sums stereo signals to mono
for the internal amplifier section. The amplifier
will operate with only one input connection (left
or right), but will require an increase in input
sensitivity to overcome the loss of signal. If a
mono input signal is to be run, we recommend
that you use a “Y-adaptor” to split the mono
signal into both inputs of the amplifier.
Input Voltage Range:
The XD600/1’s input section is designed to
accept signal voltages from 100mV – 4V. This
will accommodate all preamp level signals and
many speaker level signals.
To use speaker-level sources, simply splice the
speaker output wires of the source unit onto a
pair of RCA plugs for each input pair. (or use
JL Audio part XD-CLRAIC2-SW) No “line
output converter” is needed in most cases.
If you find that the output cannot be reduced
sufficiently with a direct speaker level signal
applied to the amplifier, you may use a “line
output converter” or voltage divider to reduce the
signal level.
INPUT SENSITIVITY CONTROLS
The control labeled “Input Sens.” can be used
to match the source unit’s output voltage to the
input stage the XD600/1 for maximum clean
output. Rotating the control clockwise will result
in higher sensitivity (louder for a given input
voltage). Rotating the control counter-clockwise
will result in lower sensitivity (quieter for a given
input voltage.)
To properly set the amplifier for maximum
clean output, please refer to Appendix A (page
12) in this manual. After using this procedure,
you can then adjust the “Input Sens.” levels
downward if this is required to achieve the
desired system balance.
Do not increase any “Input Sens.” setting for
any channel(s) of any amplifier in the system
beyond the maximum level established during
the procedure outlined in Appendix A (page 12).
Doing so will result in audible distortion and
possible speaker damage.
ENGLISH
7
FILTER CONTROLS
Most speakers are not designed to reproduce
the full range of frequencies audible by the human
ear. For this reason, most speaker systems are
comprised of multiple speakers, each dedicated
to reproducing a specific frequency range. Filters
are used to select which frequency range is sent
to each section of a speaker system. The division
of frequency ranges to different speakers can be
done with passive filters (coils and/or capacitors
between the amplifier outputs and the speakers),
which are acceptable and commonly used
for filtering between mid-range speakers and
tweeters. Filtering between subwoofer systems
and satellite speaker systems is best done with
active filters, which cut off frequency content at
the input to the amplifier. Active filters are more
stable than passive filters and do not introduce
extraneous resistance, which can degrade
subwoofer performance.
The active low-pass filter built into
the XD600/1 is designed to attenuate
frequencies above its filter frequency,
so that the system’s subwoofers do not
reproduce any audible midrange content.
This serves to improve tonal balance
and to avoid distortion. Correct use
of the filter can substantially improve
the fidelity of your audio system.
2) LP Filter Operation: The low-pass filter in the
XD600/1 is fully variable between 50 Hz and
500 Hz via the “Filter Freq.” control knob and
features the ability to select between a moderate
“12dB” per octave or a steep “24dB” per octave
slope via the “LP Fi lter Mode/Slope” switch.
Depending on the subwoofer system and
the vehicle, different slopes may be required
to produce a smooth transition to the midbass speakers in the system. Experiment to
find the slope which best matches the acoustic
requirements of your system.
Tuning Hint: A trunk mounted sub whose
output has to “fight” through a rear deck or a
back seat often benefits from the 12 dB/octave
slope which lets more upper bass content pass
through. A sub that fires directly into the
listening environment is more likely to benefit
from a 24 dB/octave slope.
Note: The above hint is not “set-in-stone”…
You should always listen to the system carefully to
determine the best choice as vehicle acoustics and
other factors play a big role in choosing the most
appropriate filter slope.
3) Precise Frequency Selection: The filter
frequency markings on the front panel of
the amplifier are for reference purposes and
are generally accurate to within 1/3 octave
or better. If you would like to select the filter
frequency with a higher level of precision,
consult Appendix B (page 13) of this manual.
This chart gives you a more accurate frequency
for each of the forty detented positions of the
frequency selection control. This method can
be very useful if the amplifier is mounted in
a location where you can’t see the front panel
markings easily.
4) Defeating the LP Filter: The Low-Pass filter
can also be defeated completely, by switching
the “LP Filter Mode/Slope” switch to the
“Off” position. This is useful if you are using
an external active crossover in the system.
With the internal crossover turned off, the
XD600/1’s upper frequency response limit is
500 Hz, due to its subwoofer-specific design.
8 | JL Audio - XD600/1 Owner’s Manual
INFRASONIC FILTER
The “Infrasonic Filter” is a 24 dB/octave highpass filter, with a fixed cutoff frequency of 30 Hz.
This filter is designed to conserve amplifier power
and protect subwoofer systems, without audibly
degrading the sub-bass output.
With ported enclosures, the use of the
“Infrasonic Filter” is highly recommended to
protect the speaker(s) from excessive excursion
below box tuning.
With sealed enclosures, the use of the filter
is less necessary, but can still help protect the
speaker system from excessive excursion.
The “Infrasonic Filter” can be completely
defeated by selecting the “Off ” position on its
switch. This bypasses all signal from flowing
through the circuit.
REMOTE LEVEL CONTROL OPTIONAL
ENGLISH
With the addition of the optional Remote
Level Control (HD-RLC), you can control the
subwoofer volume from the front of the vehicle.
The HD-RLC connects to the jack labeled
“Remote Level Control” on the Connection Panel
of the amplifier using a standard telephone cable
(supplied with the HD-RLC). If desired, multiple
XD (and HD) amplifiers can be controlled from
a single HD-RLC controller using a simple phone
line “splitter” and multiple phone cables.
When connected to the amplifier, the
HD-RLC operates as follows. At full counterclockwise rotation, the audio will mute
completely. At full clockwise rotation the level
will be the same as if the HD-RLC was not
connected at all. In other words, it operates
strictly as a level attenuator.
9
PREOUTS
The XD600/1 incorporates a pass-through
preamp output section, so that additional
amplifiers can be easily added to the system.
The preamp output delivers the same signal that
is connected to the XD600/1’s inputs.
The preamp output signal by any crossover
filter selected (if the input signal is full-range, the
preamp output will be full-range).
If you plan to use the “Preouts” to feed
a stereo amplifier, you must connect a
stereo signal to the input of the amplifier.
A mono signal into the amplifier will result
in a mono signal out of the preamp output.
SUBWOOFER OUTPUTS
The XD600/1 is designed to deliver power into
subwoofer loads equal to or greater than 2 ohms.
The XD600/1’s subwoofer outputs are
designed to accept 16 AWG - 8 AWG wire. To
connect the subwoofer wires to the amplifier,
first back out the set screws 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.
You will notice that there are two “+” positive
connections and two “–” negative connections.
This is to facilitate multiple subwoofer wiring.
The two positive and two negative connections
are connected in parallel inside the amplifier
They are not stereo outputs. Connecting two
subwoofers, each to one set of positive and
negative terminals, will result in a parallel
subwoofer connection. If only connecting one
pair of subwoofer wires, it is not necessary to use
both sets of connections.
10 | JL Audio - XD600/1 Owner’s Manual
Subwoofer loads below 2 ohms nominal are not
recommended and may cause the amplifier
to initiate a protection mode which reduces
power output.
STATUS LED / PROTECTION CIRCUITRY
There is a single multi-color LED on the top
surface of the amplifier to indicate the amplifier’s
operating status.
1 ) F l a s h i n g G r e e n : amplifier is powering up,
audio output is muted.
2) Constant Green: amplifier is on and
functioning normally, audio output is active.
3) Constant Red: lights to indicate that the
amplifier has exceeded its safe operating
temperature, putting the amplifier into a
self-protection mode, which reduces the
peak power output of the amplifier. When its
temperature returns to a safe level, the red
light will return to green and the amplifier will
return to full-power operating mode.
4) Constant Amber (yellow): Indicates
that an over-current condition has occurred and
is accompanied by a muting of the amplifier’s
output. Because the muting behavior may be
very short in duration, it may manifest itself as
an audible, repetitive ticking or thumping noise
in the output. Over-current conditions can be
caused by a speaker impedance lower than the
optimum load impedance range for the amplifier
or a short-circuit in the speaker wiring. The
latter can result from a short circuit between the
positive and negative speaker wires or between
either speaker wire and the vehicle chassis.
The “Status LED” will remain amber for a few
seconds, even if the over-current condition is of a
very short duration.
5) LED off / Amplifier Shuts Off Unexpectedly
The only condition that will shut down
an undamaged XD600/1 completely is if battery
voltage or remote turn-on voltage drops below
10 volts. The “Status LED” will turn off when
this occurs. The amplifier will turn back on
when voltage climbs back above 11 volts. If this
is happening in your system, have your charging
system and power wiring inspected.
For more information on troubleshooting this
amplifier, refer to Appendix D (pages 14, 15).
SERVICING YOUR JL AUDIO AMPLIFIER
If your amplifier fails or malfunctions, please
return it to your authorized JL Audio dealer so
that it may be sent in to JL Audio for service.
There are no user serviceable parts or fuses inside
the amplifier. The unique nature of the circuitry
in the JL Audio amplifiers requires specifically
trained service personnel. Do not attempt
to service the amplifier yourself or through
unauthorized repair facilities. This will not only
void the warranty, but may result in the creation
of more problems within the amplifier.
If you have any questions about the installation or
setup of the amplifier not covered in this manual,
please contact your dealer or technical support.