owner’s manual
600W Marine Monoblock Subwoofer Amplifier
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 (954) 443-1100 during business hours.
ProteCt Your Hearing!
installation aPPliCations
Planning Your installation
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.
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
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.
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.
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.
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.
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.).
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.
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:
• Do not mount the amplifier in the engine
compartment or in any other area that will
expose the amplifier circuitry to the elements.
Infrasonic
Filter
Frequency
Selector
(pg. 8)
LP Filter
Mode/Slope
Selection
(pg. 8)
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.
Filter
Selection
(pg. 9)
Status
LED
(pg. 11)
Input Sensitivity
Control
(pg. 7)
Chassis Ground
Connector
(pg. 5)
Left & Right
Preamp Input Jacks
(pg. 7)
Jack for
+12 V Power
Remote Turn-On
Connector
(pg. 6)
Left & Right
Preamp Output Jacks
(pg. 10)
Remote Level
Control Knob
(pg. 9)
Mono
Subwoofer Outputs
(pg. 10)
Connector
(pg. 5)
2 | JL Audio - M600/1 Owner’s Manual
3
ProduCt desCriPtion
Power ConneCtions
The M600/1 is a monoblock amplifier utilizing
JL Audio NexD™ high speed switching technology
to deliver outstanding fidelity and efficiency.
The M600/1 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).
6) Run speaker cable from the subwoofer
system(s) to the amplifier mounting
location.
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
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 M600/6 is the
only device being run from the fused main
power wire. If the fused main power wire is
shared by the M600/6 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 M600/1) 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 14)
for the recommended input sensitivity
setting method.
insulation of the wire. Failure to do so
may result in a dangerous short circuit.
Many vessels employ small (10 AWG - 6 AWG)
wire to connect the alternator’s positive
connection to the battery. To prevent voltage
drops, this wire should be upgraded to 4 AWG
when installing amplifier systems with main
fuse ratings above 60A.
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.
The M600/1’s “+12 VDC” and “Ground”
connections are designed to accept 4 AWG
power wire. 4 AWG is the required wire size for
this amplifier.
It is common for the alternator to be grounded
through its chassis. If the alternator is not
grounded through its chassis and instead employs
a small (10 AWG - 6 AWG) wire to connect to
ground, this wire should also be upgraded to 4
AWG when installing amplifier systems with main
fuse ratings above 60A.
If you are installing the M600/1 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 M600/1
with 4 AWG power wire. JL Audio ECS
fused distribution blocks are recommended
(XD-FDBU-2 and XD-FDBU-4)
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 vessel operation. Use 4 AWG or larger
power wire and a power distribution block if
additional amplifiers are being installed with
the M600/1.
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 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).
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 M600/1 is being run from that power
wire, we recommend a 50A fuse be used.
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) fuses
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.).
16) Enjoy the fruits of your labor with your
favorite music.
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.
are recommended.
5) Run signal cables and remote turn-on wire
from the source unit to the amplifier
mounting location.
4 | JL Audio - M600/1 Owner’s Manual
5
turn-on lead
inPut seCtion
inPut sensitiVitY Controls
The M600/1 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 M600/1’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.
The M600/1’s input section allows you to send
signal to the amplifier section through the use
of two differential-balanced inputs, one for the
left channel signal and one for the right channel
signal. Connection is via RCA-type jacks.
The control labeled “Input Sens.” can be
used to match the source unit’s output voltage to
the input stage the M600/1 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.)
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.
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.
input Voltage range:
The M600/1’s input section is designed to
accept signal voltages from 100mV – 4V. This
will accommodate all preamp level signals and
many speaker level signals.
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.
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.
6 | JL Audio - M600/1 Owner’s Manual
7
Filter Controls
inFrasoniC Filter
remote leVel Control (oPtional)
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 M600/1
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.
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.
The “Infrasonic Filter” is a 24 dB/octave high-
pass 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 the addition of the optional Remote
Level Control (HD-RLC), you can control the
subwoofer volume from a location of your
choosing.
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 counter-
clockwise 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.
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
M600/1’s upper frequency response limit is 500
Hz, due to its subwoofer-specific design.
With ported enclosures and infinite baffle
subwoofer systems, the use of the “Infrasonic
Filter” is highly recommended to protect the
speaker(s) from excessive excursion at inaudibly
low frequencies.
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.
2) LP Filter Operation: The low-pass filter in the
M600/1 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 Filter Mode/Slope” switch.
Depending on the subwoofer system and
the vessel, different slopes may be required to
produce a smooth transition to the mid-bass
speakers in the system. Experiment to find
the slope which best matches the acoustic
requirements of your system.
8 | JL Audio - M600/1 Owner’s Manual
9
Preouts
The M600/1 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 M600/1’s inputs.
subwooFer outPuts
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.
The M600/1 is designed to deliver power into
subwoofer loads equal to or greater than 2 ohms.
The M600/1’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.
5) LED off / Amplifier Shuts Off Unexpectedly
The only condition that will shut down
an undamaged M600/6 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 16, 17).
1 ) F l a s h i n g G r e e n : amplifier is powering up,
audio output is muted.
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.
2) Constant Green: amplifier is on and
functioning normally, audio output is active.
The preamp output signal by any crossover
filter selected (if the input signal is full-range, the
preamp output will be full-range).
3) Constant Red: Indicates 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.
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.
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.
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.
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 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 a power wire. The “Status LED” will
remain amber for a few seconds, even if the over-
current condition is of a very short duration.
Jl audio technical support:
(954) 443-1100
9:00 AM – 5:30 PM (Eastern Time Zone)
Monday - Friday
Subwoofer loads below 2 ohms nominal are not
recommended and may cause the amplifier
to initiate a protection mode which reduces
power output.
10 | JL Audio - M600/1 Owner’s Manual
11
aPPendix a:
aPPendix b:
aPPendix C:
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.
8) Increase the “Input Sens.” control until the
target voltage is observed with the voltmeter.
9) Once you have adjusted the M600/1 to its
maximum low-distortion output level,
reconnect the speaker(s). The “Input Sens.”
controls can now be adjusted downward if the
amplifier requires attenuation to achieve the
desired system balance.
Precise Frequency selection Chart
m600/1 specifications
“Filter Freq” amP Filter
general specifications:
Recommended Fuse Value: 50A
detent
number
Panel
marking
actual
Freq.
Recommended Fuse Type: MAXI® or AGU
Full counter-clockwise: 53
01 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
02 . . . . . . . . . . . “50” . . . . . . . . . . . .53
03 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
04 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
05 . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
06 . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
07 . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
08 . . . . . . . . . . . “60” . . . . . . . . . . . .61
09 . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
10 . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
11 . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
12 . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
13 . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
14 . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
15 . . . . . . . . . . . . . . . . . . . . . . . . . . . .78
16 . . . . . . . . . . . “80” . . . . . . . . . . . .81
17 . . . . . . . . . . . . . . . . . . . . . . . . . . . .85
18 . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
19 . . . . . . . . . . . . . . . . . . . . . . . . . . . .93
20 . . . . . . . “12 o’clock”. . . . . . . .97
21 . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
22 . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
23 . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
24 . . . . . . . . . . “120” . . . . . . . . . . 120
25 . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
26 . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
27 . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
28 . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
29 . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
30 . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
31 . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
32 . . . . . . . . . . “200” . . . . . . . . . . 227
33 . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
34 . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
35 . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
36 . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
37 . . . . . . . . . . . . . . . . . . . . . . . . . . . 426
38 . . . . . . . . . . “500” . . . . . . . . . . 447
39 . . . . . . . . . . . . . . . . . . . . . . . . . . . 467
Full-clockwise: 470
input sections:
No. of Inputs: One Stereo Pair
necessary equipment
• Digital AC Voltmeter
Input Type: Differential-balanced with RCA jack inputs
Input Range: 100mV - 4V RMS
• CD with a sine-wave test tone recorded at
0 dB reference level in the frequency range
to be amplified for that set of channels
(50 Hz for subwoofer channels, 1 kHz for a
midrange application). Do not use attenuated
test tones (-10 dB, -20 dB, etc.).
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.
amplifier section:
Amplifier Topology: NexD™ High Speed Class D
Power Supply: Unregulated MOSFET switching type
rated Power at 14.4V with less than
1% tHd+noise (20Hz - 20 kHz)
400W RMS x 1 @ 4 ohms
the nine-step Procedure
1) Disconnect the subwoofer(s) from the
amplifier’s speaker output connectors.
It will be necessary to re-adjust the
“Input Sens.” 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.
600W RMS x 1 @ 2 ohms
rated Power @ 12.5V with less than
1% tHd + noise (20Hz - 20 kHz)
300W RMS x 1 @ 4 ohms
2) Turn off all processing (bass/treble, loudness,
EQ, etc.) on the source unit, processors (if
used) and amplifier. Set fader control to center
position and subwoofer level control to 3/4 of
maximum (if used to feed the M600/1).
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 chart on this page, determine the target
voltage for input sensitivity adjustment according
to the nominal impedance of the subwoofer
system connected to the amplifier outputs.
6) Verify that you have disconnected the
subwoofer(s) before proceeding. Play a track
with an appropriate sine wave (within the
frequency range to be amplified by the M600/1)
at 3/4 source unit volume.
500W RMS x 1 @ 2 ohms
Signal to Noise Ratio:
>87 dB referred to rated power
(A-weighted, 20 Hz-20 kHz noise bandwidth)
>67 dB referred to 1W
nom. impedance
target aC Voltage
40.0 V
4Ω
3Ω
2Ω
1Ω
(A-weighted, 20 Hz-20 kHz noise bandwidth)
Frequency Response: 7 Hz - 500 Hz (+0, -1dB)
Damping Factor:
37.3 V
34.6 V
>1000 @ 4 ohms / 50 Hz
Not Recommended
>500 @ 2 ohms / 50 Hz
amplifier Filters:
Amplifier Low-Pass Filter:
State-variable, 12 dB/octave Butterworth or 24 dB/octave
Linkwitz-Riley with continuously variable cutoff frequency
selection from 50 - 500 Hz (defeatable).
Infrasonic Filter:
7) Connect the AC voltmeter to the speaker output
connectors of the amplifier. Make sure you test
the voltage at the correct connectors (+ and –).
24 dB/octave Butterworth @ 30 Hz (defeatable).
Preamp output:
Buffered pass-through type.
dimensions(lxwxH):
8.52” x 7.09” x 2.05” (217mm x 180mm x 52mm)
Due to ongoing product development, all specifications are subject to
change without notice.
12 | JL Audio - M600/1 Owner’s Manual
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aPPendix d: troublesHooting
“How do i properly set the input sensitivity on my amplifier?”
“my amplifier shuts off once in a while, usually at higher volumes.”
Check your voltage source and grounding point. The power supply
Please refer to Appendix A (page 12) to set the input sensitivity for
maximum, low-distortion output.
of the M600/1 will operate with charging system voltages
down to 10V. Shutdown problems at higher volume levels
can occur when the charging system voltage (or remote
turn-on voltage) drops below 10V. These dips can be of
very short duration making them extremely difficult to
detect with a common DC voltmeter. To ensure proper
voltage, inspect all wiring and termination points. It may
also be necessary to upgrade the ground wire connecting
the battery to the vessel’s electrical ground and the power
wire connecting the alternator to the battery. Many
vessels employ small (10 AWG - 6 AWG) wire to ground
the battery and to connect the alternator 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. Grounding problems are the
leading cause of misdiagnosed amplifier “failures.”
“my amplifier doesn’t turn on.”
Check the 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 the 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 to 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.
“i hear a repetitive ticking or popping sound coming out of the speaker(s).”
Check the speaker wires for a possible short, either between
the positive and negative leads or between either
“my amplifier turns on, but there is no output.”
Check the input signal using an AC voltmeter to measure the
voltage from the source unit while an appropriate low-
frequency test tone is played through the source unit
(disconnect the input cables from the amplifier prior to this
test). 50 Hz is a good choice. A steady, sufficient voltage
(between 0.1 and 4.0-volts) should be present at the output of
the signal cables.
Check the 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. Remove the speaker wires from the amplifier
while doing this to prevent unpleasant noise and possible
speaker damage. Turn the volume up approximately half
way. 5V AC 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.
speaker lead and the vessel’s electrical ground. If a
short is present, you will experience distorted and/
or attenuated output. The “Status LED” will turn
Amber (yellow) in this situation. It may be helpful to
disconnect the speaker wires from the amplifier and use
a different set of wires connected to a test speaker.
Check the nominal load impedance to verify that each channel
of the amplifier is driving a load equal to or greater than
2 ohms in stereo mode (4 ohms bridged).
“my amplifier’s output fluctuates when i tap on it or hit a bump.”
Check the 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 the input connectors to ensure that they all are making good
contact with the input jacks on the amplifier.
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installation notes:
Use this diagram to document your amplifier’s switch and control positions.
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installation notes:
installation notes:
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