owner’s manual
Monoblock Subwoofer Amplifiers
Thank you for purchasing a JL Audio amplifier for
your automotive sound system.
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 our Technical Support Department
at (954) 443-1100 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 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:
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.
Chassis Ground
(pg. 5)
+12 V Power
(pg. 5)
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.
Speaker Outputs
(pg. 10)
Remote Turn-On
(pg. 6)
Power Status
Frequency Selector
(pg. 11)
(pg. 8)
Protection Status
Input Sensitivity
(pg. 11)
(pg. 7)
Installation Applications
This amplifier is designed for operation in
vehicles with 12V, 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
the warranty.
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.
Input Jack
(pg. 6,7)
Left & Right
Bass Boost
Preamp Output Jacks
(pg. 8)
(pg. 9)
Left & Right
Preamp Input Jacks
Level Control
(pg. 6)
(pg. 9)
JL Audio
JX250/1 • JX500/1 • JX1000/1D
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 using appropriate
hardware 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.
Product Description
JL Audio JX monoblock subwoofer
amplifiers are specifically designed to drive
subwoofers. Their frequency response is
limited to the range below 150 Hz., making
them unsuitable for driving midrange speakers
or tweeters. For detailed specifications,
please refer to Appendix B (page 13).
Typical Installation Sequence
The following represents the sequence
for a typical amplifier installation, using an
aftermarket source unit or OEM Interface
product. 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) D
isconnect the negative battery post
connection and secure the disconnected cable
to prevent accidental re-connection during
installation. This step is not optional!
2) R
un 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. See
next page for appropriate wire size.
3) C
onnect 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 connected to the amplifier.
4) R
un signal cables (RCA cables) and remote
turn-on wire from the source unit to the
amplifier mounting location.
5) R
un speaker wire from the speaker systems
to the amplifier mounting location.
6) F
ind a good, solid metal grounding point
close to the amplifier and connect the
negative power wire to it using appropriate
hardware. Use the same size power wire
used for the +12V connection, no longer
than 36 inches (90 cm) from the amplifier's
ground (GND) connector 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 using
appropriate hardware.
8) Connect the positive and negative power
wires to the amplifier.
9) Connect the remote turn-on wire
to the amplifier.
10) Connect the input cables
to the amplifier.
11) Connect the speaker wires 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 power wire fuse (see next page for
correct value) 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
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.
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 person during installation.
The amplifier’s “+12 VDC” (positive) and
“Ground” (ground) connections are designed to
accept up to 4 AWG power wire.
Minimum Power / Ground
Wire Size Requirements:
JX250/1: 8 AWG
JX500/1: 4 AWG
JX1000/1D: 4 AWG
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.).
The above wire gauge recommendations
assume no other amplifiers are connected
to the same wire. Use larger wire with
a fused distribution block (or separate
wires) for multiple amplifiers.
If you are installing this amplifier 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 and should connect to the
JX monoblock with 4 AWG power wire (8 AWG is
sufficient for the JX250/1 only).
To connect the power and ground wires
to the amplifier, strip 1/2-inch (12 mm) of
insulation from each wire and insert the
bare wire into the appropriate terminal block
positions on the JX250/1. Use the supplied
JL Audio
JX250/1 • JX500/1 • JX1000/1D
2.5 mm hex wrench to secure the wire via
the screw on the top of each terminal.
The “Ground” connection should be made
using 4 AWG wire (8 AWG is sufficient for
JX250/1 only) 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. The use of a #10 sheet metal screw
and star washer to lock down the connection is
advisable. Alternatively, you can use a specialized
grounding lug, such as the JL Audio XB-MGLU.
Any wires run through metal barriers (such
as firewalls), must be protected with a high
quality insulating 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
JX250/1: 30A (AGU or MAXI®)
JX500/1: 60A (AGU or MAXI®)
JX1000/1D: 80A (AGU, ANL or MAXI®)
An appropriate fuse at the main power wire(s)
to the amplifier(s) is vital for vehicle safety! This
fuse must be installed within 18 inches (45 cm)
of the positive battery post connection. If the JX
monoblock is the only device connected to this
main wire, use the corresponding fuse value listed
above (no other fuse is required in this situation).
When running multiple devices from one
main power wire, the main fuse value and rating
of the main power wire must be high enough
for all of the equipment being run from it. Use a
fused distribution block to split the main power
wire feed to each device, with appropriate fusing
and power wire for each device.
REMOTE turn-On
The JX monoblock amplifier is turned on
and off using a conventional +12V remote
turn-on lead, typically controlled by the
source unit’s remote turn-on output.
The JX monoblock amplifier offers
two input connection methods, one for
high-level (speaker level) signals and one
for low-level (preamp level) signals.
2) Hi-Level Inputs: If your system does not offer
a preamp level signal option, you can connect
speaker level signals directly to the “Hi-Level
Inputs” connector using the supplied mating
connector and wire harness. Simply splice the
appropriate left/right and positive/negative
wires to the included harness and plug the
harness into the “Hi-Level Inputs” connector
on the amplifier. The JX monoblock will
attenuate the high-level signal to make it
compatible with its input stage.
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 ignitionswitched circuit.
18 AWG wire is more than adequate for the
remote turn-on connection. To connect the
remote turn-on wire to the amplifier, strip 1/2inch (12 mm) of insulation from the wire and
insert it into the “Remote” receptacle on the
power connector. Tighten the connector down
using the supplied 2.5 mm hex wrench.
Make sure you observe correct polarity in
making the “Hi-Level Input” connections.
Failure to do so will result in a complete loss of
signal (no bass).
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. For this reason, when feeding a mono
input signal into the "Low-Level Inputs", use a
Y-adaptor splitter to split the mono signal and
connect it to both the Left and Right Low-Level
Inputs of the amplifier.
When feeding a mono signal to the "Hi-Level
Inputs", connect it in parallel to both left and
right input wires.
1) L
ow-Level Inputs: A standard left/
right pair of RCA type jacks is used for
preamp level (low-level) signal input on
the JX monoblocks. This is the preferred
connection method whenever available.
Located to the left of the input connectors is a
rotary control labeled “Input Sens.”. This rotary
control can be used to match the source unit’s
output voltage to the input stage of the amplifier
for maximum clean output.
JL Audio
The connections for the “Hi-Level Inputs” plug wires
are as follows from left to right on the plug:
White: Left Positive (+)
White/Black: Left Negative (–)
Black: Common Ground (rarely used)*
Gray: Right Positive (+)
Gray/Black: Right Negative (–)
*The only time you will use the “Common
Ground” connection is with some older (pre1980’s) factory systems or head units that ground
their speakers to chassis ground. To use this
connection, ground the black wire on the plug to
chassis ground and only connect the Left and Right
Positive plug wires to the factory radio outputs.
If you plan to use the preamp outputs to feed a
stereo amplifier, you must connect stereo
signals to the inputs of the amplifier. A mono
signal into the amplifier will result in a mono
signal out of its preamp output.
JX250/1 • JX500/1 • JX1000/1D
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 level of the
amplifier by adjusting the input sensitivity
downward, if the amplifier requires attenuation to
achieve the desired system balance.
Do not increase the “Input Sens.” setting for
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.
Low-pass filter Control
The JX monoblock employs a 12dB/octave
low-pass active filter for its internal channel. This
feature is designed to attenuate frequencies above
its filter frequency, so that the system’s subwoofers
do not reproduce any audible mid-range content.
The low-pass filter is fully variable between
50 Hz and 200 Hz via the “Filter Frequency”
control knob. 80 Hz (as shown in the diagram
below) is a good starting point for system tuning.
The JX monoblock incorporates a passthrough preamp output (Preouts) section,
designed to make multiple amplifier systems
easy to set up. This section consists of a pair
of RCA-type jacks marked “Preouts”.
“BASS BOost” Control
The JX monoblock includes a single band,
boost-only bass equalizer controlled by a rotary
knob marked “Bass Boost”. This control has a
boost range of 0dB (full-counterclockwise) to
+12dB (full-clockwise) and is centered at 45 Hz.
With the optional RBC-1 Remote Level
Control (sold separately), you can control the
subwoofer volume from the front of the vehicle.
The RBC-1 connects to the jack
labeled “Remote Level Control” on the
Connection Panel of the JX Monoblock
amplifier, using a standard telephone
cable (supplied with the RBC-1).
When connected to the amplifier, the
Remote Level Control operates as follows.
At full counter-clockwise rotation, the audio
will mute completely. At full clockwise
rotation the level will be the same as if
the RBC-1 was not connected at all. In
other words, it operates strictly as a level
attenuator. This control will not affect the
"Bass Boost" feature of the JX Monoblock.
These preamp outputs deliver the same signal
that is being fed to the Low-Level inputs. (If the
input signals are full-range, the preamp outputs
will be full-range). This signal is not affected by
the bass boost or Filter processing selected for the
The "Preouts" of the JX250/1 and JX500/1 will
not pass signals from the Hi-Level inputs. The
JX1000/1D will pass signals from the Hi-Level
inputs and will attenuate them to Low-Level.
JL Audio
Care should be taken to securely mount this
control in a manner that does not interfere with
vehicle operation.
When setting the amplifier’s input sensitivity,
the Remote Level Control should be unplugged or
at full clockwise rotation (maximum level).
JX250/1 • JX500/1 • JX1000/1D
Subwoofer connection to the JX monoblock
is straightforward and takes place at the
far right of the power/speaker connection
panel. Two positive (“+”) connections and
two negative (“–”) connections are available
via a connector labeled “Speaker Output
(Mono)”. The dual connections allow for two
separate speaker wire runs to be parallelconnected to the amplifier’s mono output.
Status Indicator Lights /
Protection Circuitry
Do NOT attempt to “bridge” two JX
monoblocks together or combine their output
to a single load in any manner. Doing so will
damage the amplifier(s).
Before reconnecting the battery ground and
turning the system on, verify that all control
settings on the amplifier are set according to
the needs of the system.
Servicing your 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.
There are two status indicator lights on the
amplifier’s control panel. These are as follows:
1) “Power” (Green): Located at the far left of the
amplifier’s control panel, this LED lights to
indicate that the amplifier is turned on and
operating normally.
Speaker loads below 2Ω nominal are not
recommended and will cause the amplifier to
enter into a protection mode.
2) “Protect” (Red): Indicates that the amplifier
protection circuitry has been activated
to prevent product failure due to thermal
overload, short-circuit or a dangerously
low impedance connected to the amplifier
outputs. Connecting the speaker output to
an impedance lower than 2 ohms will cause
this protection mode to activate. When this
protection mode is activated, the amplifier will
shut down to protect its circuitry. When the
problem is corrected, the amplifier will return
to normal operation and the “Protect” LED
will shut off.
Do not chassis ground any speakers connected
to this or any other JL Audio amplifier. Doing so
will cause the amplifier to go into protection.
To connect the speaker wires to the amplifier,
strip 1/2-inch (12 mm) of insulation from each
speaker wire and insert them into their
appropriate connector (observing correct
polarity). Then, tighten each connector using the
supplied 2.5 mm hex wrench.
JL Audio Technical Support:
(954) 443-1100
9:00 AM – 5:30 PM (Eastern Time Zone)
Monday - Friday
JL Audio
JX250/1 • JX500/1 • JX1000/1D
Appendix A:
Input Sensitivity Level Setting
Following the directions below will allow the
installer to adjust the input sensitivity of each
amplifier channel pair simply and easily in just a
few minutes using equipment which is commonly
available in installation bays.
Necessary Equipment
• Digital AC Voltmeter
• CD with a sine-wave test tone recorded at
0 dB reference level in the frequency range
to be amplified (50 Hz is a good choice). Do not
use attenuated test tones (-10 dB, -20 dB, etc.).
The Nine-Step Procedure
1) D
isconnect the subwoofer(s) from the
amplifier’s subwoofer output connector (you
need only disconnect Pos. or Neg., not both).
2) Turn off all processing (bass/treble, loudness,
EQ, etc.) on the source unit, processors (if
used) and amplifier. Set the source unit's fader
control to center position and its subwoofer level
control to 3/4 of maximum. If connected, set the
amplifier’s Remote Level Control at maximum
(full clockwise).
3) Turn the amplifier's “Input Sens.” control all
the way down.
4) Set the source unit volume to 3/4 of full
volume. This will allow for reasonable gain
overlap with moderate clipping at full volume.
5) Using the charts on this page, determine the
target voltage for input sensitivity adjustment
according to the nominal impedance of the
speaker system connected to the amplifier
outputs. Make sure you reference the appropriate
chart for your specific JX monoblock model.
6) Verify that you have disconnected the speakers
before proceeding. Play a track with an
appropriate sine wave (50 Hz is recommended)
at 3/4 source unit volume.
7) Connect the AC voltmeter to the speaker output
connectors of the amplifier. Make sure you test
the voltage at the correct connectors (+ and –).
8) Increase the “Input Sens.” control until the
target voltage is observed with the voltmeter.
9) Once you have adjusted the amplifier to
its maximum low-distortion output level,
reconnect the speaker(s) and listen to the
system. The “Input Sens.” controls can
now be adjusted downward if the amplifier
requires attenuation to achieve the desired
system balance.
Appendix b:
Input Section (all models):
JX500/1 Specifications:
Low-Level Input: Single-ended with RCA jacks
Amplifier Topology: Class A/B
Low-Level Input Range: 200mV - 4V RMS
Power Supply: Unregulated PWM switching type
High-Level Input: Single-ended with molded connector
Frequency Response: 10 - 150 Hz (+0/– 1 dB)
High-Level Input Range: 2.0V - 10.0V RMS
Signal to Noise Ratio:
>90 dBA referred to highest rated power, >63 dBA
Do not increase any “Input Sens.” setting for
any amplifier channel or channel pair in the
system beyond the maximum level established
during this procedure. Doing so will result in
audible distortion and possible speaker damage.
It will be necessary to re-adjust the
“Input Sens.” for the affected channels if any
equalizer boost is activated after setting the
“Input Sens.” with this procedure. This applies
to any EQ boost circuit, including source unit
tone controls or EQ circuits. EQ cuts will not
require re-adjustment.
Signal Processing (all models):
referred to 1W (20 Hz - 20 kHz noise bandwidth)
Filter Type: 12dB/octave Low-Pass with continuously
Damping Factor: >160 @ 4 ohms / >80 @ 2 ohms
variable cutoff frequency selection from 50 - 200 Hz.
THD + Noise @ Rated Power: 1 %
Not defeatable.
Rated Continuous (RMS) Power @ 14.4V:
Preamp Output: 2-Ch., pass-through with RCA-type jacks
340W RMS x 1 @ 4Ω
Bass Boost: Single-band with 45 Hz center frequency,
400W RMS x 1 @ 3Ω
adjustable from 0 to +12dB.
500W RMS x 1 @ 2Ω
Remote Level Control: Via optional, wired RBC-1 remote
Rated Continuous (RMS) Power @ 12.5V:
control knob. Full mute to 0 dB range. (RBC-1 is sold
270W RMS x 1 @ 4Ω
340W RMS x 1 @ 3Ω
410W RMS x 1 @ 2Ω
JX250/1 Specifications:
Recommended Fuse Value (Type): 60A (MAXI or AGU)
Amplifier Topology: Class A/B
Minimum Copper Power/Ground Wire Gauge: 4 AWG
Power Supply: Unregulated PWM switching type
Dimensions (LxWxH):
Frequency Response: 10 - 150 Hz (+0/– 1 dB)
13.70" x 7.68" x 2.15" (348 mm x 195 mm x 53 mm)
Signal to Noise Ratio:
Net Weight: 7.9 lbs. (3.58 kg)
>87 dBA referred to highest rated power, >63 dBA
Nom. Impedance
Target AC Voltage
26.5 V
25 V
22.5 V
Nom. Impedance
Target AC Voltage
36.9 V
34.6 V
31.6 V
referred to 1W (20 Hz - 20 kHz noise bandwidth)
JX1000/1D Specifications:
Damping Factor: >160 @ 4 ohms / >80 @ 2 ohms
Amplifier Topology: Class D
THD + Noise @ Rated Power: 1 %
Power Supply: Unregulated PWM switching type
Rated Continuous (RMS) Power @ 14.4V:
Frequency Response: 20 - 150 Hz (+/– 1 dB)
175W RMS x 1 @ 4Ω
Signal to Noise Ratio:
210W RMS x 1 @ 3Ω
>75 dBA referred to highest rated power, >45 dBA referred
250W RMS x 1 @ 2Ω
to 1W (20 Hz - 20 kHz noise bandwidth)
Rated Continuous (RMS) Power @ 12.5V:
Damping Factor: >1000 @ 4 ohms
130W RMS x 1 @ 4Ω
THD + Noise @ Rated Power: 1 %
170W RMS x 1 @ 3Ω
Rated Continuous (RMS) Power @ 14.4V:
210W RMS x 1 @ 2Ω
500W RMS x 1 @ 4Ω
Recommended Fuse Value (Type): 30A (MAXI or AGU)
750W RMS x 1 @ 3Ω
Minimum Copper Power/Ground Wire Gauge: 8 AWG
1000W RMS x 1 @ 2Ω
Dimensions (LxWxH):
Rated Continuous (RMS) Power @ 12.5V:
10.94" x 7.68" x 2.09" (278 mm x 195 mm x 53 mm)
500W RMS x 1 @ 4Ω
Net Weight: 6.0 lbs. (2.72 kg)
700W RMS x 1 @ 3Ω
900W RMS x 1 @ 2Ω
Nom. Impedance
Target AC Voltage
44.7 V
44.7 V
44.7 V
Recommended Fuse Value (Type): 80A (MAXI or ANL)
Minimum Copper Power/Ground Wire Gauge: 4 AWG
Dimensions (LxWxH):
10.94" x 7.68" x 2.09" (278 mm x 195 mm x 53 mm)
Net Weight: 7.0 lbs. (3.18 kg)
Due to ongoing product development, all specifications are subject to
change without notice.
JL Audio
JX250/1 • JX500/1 • JX1000/1D
“How do I properly set the input sensitivity on my amplifier”
Please r efer to Appendix A (page 12) to set the input sensitivity for
maximum, low-distortion output.
“My amplifier doesn’t turn on”
Check t he fuse, not just visually, but with a continuity meter. It is
possible for a fuse to have poor internal connections that
cannot be found by visual inspection. It is best to take the
fuse out of the holder for testing. If no problem is found with
the fuse, inspect the fuse-holder.
Check t he integrity of the connections made to each of the
“+12VDC”, “Ground”, and “Remote” terminals. Ensure
that no wire insulation is pinched by the terminal set screw
and that each connection is tight.
Check t o make sure there is +12V at the “Remote” connection of the
amplifier. In some cases, the turn-on lead from the source unit
is insufficient to turn on multiple devices and the use of a relay
is required. To test for this problem, jump the “+12VDC” wire
to the “Remote” terminal to see if the amplifier turns on. If this
does not work, proceed to the next step.
“My amplifier’s output fluctuates when I tap on it or hit a bump”
Check t he connections to the amplifier. Make sure that the
insulation for all wires has been stripped back far enough to
allow a good contact area inside the terminal block.
Check t he input connectors to ensure that they all are making good
contact with the input jacks on the amplifier.
JL Audio
“My amplifier turns on, but there is no output”
Check t he input signal using an AC voltmeter to measure the
voltage from the source unit while an appropriate test tone is
played through the source unit (disconnect the input cables
from the amplifier prior to this test). The frequency used
should be in the range that is to be amplified by the amplifier
(example: 50 Hz for a sub bass application or 1 kHz for a full
range / high-pass application). A steady, sufficient voltage
(between 0.2 and 8.0-volts) should be present at the output of
the signal cables.
Check t he output of the amplifier. Using the procedure explained in
the previous check item (after plugging the input cables back
into the amplifier) test for output at the speaker outputs of
the amplifier. Unless you enjoy test tones at high levels, it is
a good idea to remove the speaker wires from the amplifier
while doing this. Turn the volume up approximately half
way. 5V or more should be measured at the speaker outputs.
This output level can vary greatly between amplifiers but it
should not be in the millivolt range with the source unit at
half volume. If you are reading sufficient voltage, check your
speaker connections as explained below.
Check to ensure that the speaker wires are making a good
connection with the metal inside the terminal block. The
speaker wire connectors are designed to accept up to 8 AWG
wire. Make sure to strip the wire to allow for a sufficient
connection with the metal inside the terminal block.
JX250/1 • JX500/1 • JX1000/1D
Use this diagram to document your amplifier’s switch and control positions.
JL Audio
JX250/1 • JX500/1 • JX1000/1D
JL Audio
JX250/1 • JX500/1 • JX1000/1D
Limited Warranty - Amplifiers (USA)
JL AUDIO warrants this product to be free of defects in materials and workmanship for a
period of two (2) years. The warranty is extended to three (3) years total if installation is performed by an
authorized JL Audio dealer using a JL Audio Premium Power Connection System for power wiring.
This warranty is not transferrable and applies only to the original purchaser from an authorized
JL AUDIO dealer. Should service be necessary under this warranty for any reason due to manufacturing
defect or malfunction, JL AUDIO will (at its discretion), repair or replace the defective product with new
or remanufactured product at no charge. Damage caused by the following is not covered under warranty:
accident, misuse, abuse, product modification or neglect, failure to follow installation instructions,
unauthorized repair attempts, misrepresentations by the seller. This warranty does not cover incidental
or consequential damages and does not cover the cost of removing or reinstalling the unit(s). Cosmetic
damage due to accident or normal wear and tear is not covered under warranty.
Warranty is void if the product’s serial number has been removed or defaced.
Any applicable implied warranties are limited in duration to the period of the express warranty as
provided herein beginning with the date of the original purchase at retail, and no warranties, whether
express or implied, shall apply to this product thereafter. Some states do not allow limitations on implied
warranties, therefore these exclusions may not apply to you. This warranty gives you specific legal rights,
and you may also have other rights which vary from state to state.
If you need service on your JL AUDIO product:
All warranty returns should be sent to JL Audio ’s Amplifier Service Facility freight-prepaid through
an authorized JL Audio dealer and must be accompanied by proof of purchase (a copy of the original
sales receipt). Direct returns from consumers or non-authorized dealers will be refused unless specifically
authorized by JL Audio with a valid return authorization number.
Warranty expiration on products returned without proof of purchase will be determined from the
manufacturing date code. Coverage may be invalidated as this date is previous to purchase date. Nondefective items received will be returned freight-collect. Customer is responsible for shipping charges and
insurance in sending the product to JL Audio. Freight damage on returns is not covered under warranty.
For Service Information in the U.S.A. please call
JL Audio Customer Service: (954) 443-1100
9:00 AM – 5:30 PM (Eastern Time Zone)
JL Audio, Inc
10369 North Commerce Pkwy.
Miramar, FL 33025
(do not send product for repair to this address)
International Warranties:
Products purchased outside the United States of America are covered only
by that country’s distributor and not by JL Audio, Inc.
JX250/1 • JX500/1 • JX1000/1D-CH-11-2010
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