JL Audio HD600/4 User manual

OWNER'S MANUAL
H:JBOO/4
4-Channel Class-D Full-Range Amplifier
Thank you for purchasing a IL 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 IL 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 IL Audio dealer for assistance. If you need further assistance,
please call the IL Audio Technical Support Department
at [phone] during business hours.

PROTECT YOUR HEARING!
We value you as along-term customer. For
that reason,
we urge you to practice restraint in
the operation ofthis 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 aspeaker 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 arecord
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
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 asecond amplifier,
including an identical one.
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.
Power Status Filter Slope Input Sensitivity Input Mod
Indicator Selection Control Selection
(pg. 16) (pg. 11) (pg. 10) (pg. 9)
~
Filter Mode jFilter Frequency jInputVoltage j
Selection Selector Selection
~ ~ (pg.l1) - - (pg.11) - - (pg.tO) --
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Status t REAR CHANNEL CONTROLS L-
JL AUDIO. HOSe
Chassis Ground Front Left &Right Left &Right Preamp
Connector Channel Input Jacks Output Jacks
(pg.6-7) (pg.9) (pg.13) Jacdo'
+ 12 VPower jRemote Turn-On j Rear Left &Right jRemote' Level
_-r,r----Connector _ _ Connector __ _Channel Input Jacks _ __ Contro, Knob _
r=~===+t::===-=-(pg 6 7) (pg 6-7) (pg 9) pg 13,
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2I JL Audio -HD600/4 Owner's Manual

Cooling Efficiency Considerations:
Your JL Audio amplifier employs an
advanced type
of heat management, called
ReaISink'". This feature takes advantage
of
convection and radiation effects to remove
heat from the amplifier circuitry. For
optimum
cooling performance, the vertical heat sinks
located at the sides
of the amplifier should be
exposed to as large avolume
of air as possible.
Enclosing the amplifier in asmall, 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 afan. In normal
applications, fan-cooling
is not necessary.
If mounting the amplifier under aseat,
make sure there
is at least 1inch (2.5 cm) of
space above the amplifier's outer shell to permit
proper cooling.
SafetyConsiderations:
Your amplifier needs to be installed in adry,
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 acollision or asudden 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 agas 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.
Preouts From Input Sensitivity Filter Slope
Selection Control Selection
emote
Level (pg.13) (pg.10) (pg.11)
Control jInputVoltage jFilter Frequency jFilter Mode
Selection Selection Selector Selection
(pg.13) - - (pg.10) - - Ipg.11) - - Ipg.
11) --~rT-_~
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Rear
Speaker Outputs
Ipgs.14-15)
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Front
Speaker Outputs
Ipgs.
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3

PRODUCT DESCRIPTION
The JL Audio HD600/4 is avery powerful
and compact four-channel, full-range amplifier
utilizing patented Single Cycle Control'"
Class Dtechnology for all channels. This
groundbreaking technology delivers reference-
grade sonic performance while requiring
far less current from the vehicle's electrical
system than aconventional amplifier.
JL Audio's exclusive RJ.P.S. power supply
design optimizes the output
of each channel pair
for any impedance between
1.5 and 4ohms per
channel (3-8 ohms bridged) allowing you to get
full use
of the HD600/4's performance capabilities
with awide range
of speaker systems.
The tightly regulated power supply design also
means that the HD600/4's clean power output
capability remains stable over awide range
of
vehicle voltages, resulting in enhanced fidelity.
The HD600/4 flexible, studio-grade signal
processing allows it to be deployed in awide
range
of system applications:
I) As afour-channel (150W x 4) full-range
amplifier, delivering full-range signals to two
separate stereo speaker systems (front and rear,
for example).
2) As apowerful (150W x 4) four-channel satellite
amplifier in abi-amplified system, delivering
high-passed signals to front and rear speaker
systems. Preamp outputs permit connection
of a
separate amplifier to drive the subwoofer system.
3) As a600W full-system amplifier in
bi-amplified mode with one channel pair
driving subwoofers in low-pass mode (l50W
x 2
or 300W x I) and the other channel pair
driving main speakers in high-pass mode
(150W x
2).
4) As avery powerful (300W x 2) full-range
amplifier, delivering full-range signals to a
stereo speaker system.
4I JL Audio -HD600/4 Owner's Manual
5) As avery powerful (300W x 2) two-channel
satellite amplifier in abi-amplified system,
delivering high-passed signals to astereo
speaker system. Preamp outputs permit
connection
of aseparate amplifier to drive the
subwoofer system.
6) As apowerful (300W x 2) two-channel
subwoofer amplifier in abi-amplified system,
delivering low-passed signals to adual
subwoofer system. Preamp outputs permit
connection
of aseparate amplifier to drive the
satellite speakers.
The HD600/4's flexible input and crossover
sections permit operation with awide variety
of
source units and system configurations. It can be
operated with asingle pair
of stereo inputs or with
separate inputs for its front and rear channels.
The HD600/4's preamp output can send pass-
through signals from the Front Inputs only or
it
can sum all four input channels to feed anon-
fading signal to aseparate subwoofer amplifier.
As
we said, it's very flexible.

TYPICAL INSTALLATION SEQUENCE
The following represents the sequence for
atypical 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 power wire from the battery location
to the amplifier
mounting location, taking
care to route
it in such away that it will
not be damaged
and will not interfere with
vehicle operation. 4
AWG is recommended
for wire
runs greater than 72 inches (180
cm) in length. Use of8 AWG power wire is
acceptable for shorter runs, such as from a
power distribution block to the amplifier
or
from a trunk-mounted battery. Use a 2 AWG
or 1/0 AWG main power wire with apower
distribution block when additional amplifiers
are being installed with the HD600/4
and
powered from the same main power wire.
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 connected to the amplifier.
4) Run signal cables (RCA cables) and remote
turn-on wire from the source unit or interface
processor to the amplifier
mounting location.
5) Run speaker wire from the speaker systems to
the amplifier mounting location.
6) Find agood, solid, bare metal grounding
point close to the amplifier and connect the
negative power wire to it using appropriate
hardware. Use
minimum 8AWG power wire,
no longer than 36 inches (90 cm) or 4 AWG
wire up to 60 inches
(150 cm) long from the
amplifier to the
ground connection point. In
some vehicles, it may be necessary to upgrade
the battery's
ground wire as well. (See page 7
for
important notice).
7) Securely mount the amplifier using
appropriate hardware. (See page 8for detailed
mounting instructions).
8) Connect the remote turn-on wire and the
positive
and negative power wires to the
amplifier's power connector plug.
Then insert
the power connector plug into the amplifier's
power connector receptacle, pushing firmly.
9) Connect the RCA input cables
to the amplifier.
10) Connect the speaker wires to the speaker
connector plugs
and insert the plugs firmly
into the speaker
connector receptacles.
11) Carefully review the amplifier's control
settings to make sure that they are set
according to the needs
of the system.
12) Install power wire fuse (SOA for a
single HD600/4)
and reconnect the negative
battery post terminal.
13) Turn on the source unit at alow level
to double-check that
the amplifier is
configured correctly. Resist the temptation
to
crank it up until you have verified the
control settings.
14) Make necessary adjustments to the input
sensitivity controls to
obtain the right
overall
output and the desired balance
in the system. See Appendix C(pages
18, 19)
for the recommended input sensitivity
setting method.
15) Enjoy the fruits of your labor with your
favorite music.
5

POWER AND TURN-ON 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.
DIMPORTANTI
We do not recommend the use of "copper-
clad aluminum wire" or "eCA" wire because
this wire is significantly less conductive than
pure copper wire. Only use pure copper power
wire, such as
JL Audio's MetaWire·M
•
Tinned
copper wire (silver color) is acceptable as the
tin-plating is only a very minor component of
the wire.
Fuse Requirements
The installation of afuse on each power wire,
within
18 wire inches (45 cm) of the positive
battery terminal
is vital to protect the wire and
the vehicle from fire in the event
of acollision or
short-circuit. 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
HD600/4
is being run from that power wire, we
recommend a50A fuse be used. AGU (big glass
fuse).
AFS (small blade fuse) or MaxiFuse'" (big
plastic-body fuse) types are recommended.
If
other amplifiers are also being powered from the
wire
and exceed 80 amps in total fuse rating, we
recommend the use of an ANL (large-blade) fuse
and holder. Please consult with your JL Audio
dealer to make sure that the wire, fuse holder
and
fuse rating you have selected are appropriate for
your system's needs.
No fuse
is required or recommended directly
before the amplifier power connection.
If one is
desired, use a 50A AGU, AFS or MaxiFuse'" type
in
an appropriate fuse block.
Ground Connection
The chassis ground connection must be
made using 4
AWG or 8 AWG pure copper
wire and should be kept
as short as possible,
while accessing asolid piece
of sheet metal
in the vehicle. The surface
of the sheet metal
should be sanded at the contact point to create
aclean, metal-to-metal connection between
the chassis and the termination
of the ground
wire with abrass
or copper power ring. For
optimal grounding,
we recommend the
use
of a JL Audio ECS master ground lug
(XB-MGLU). Alternatively, asheet metal
screw
or bolt can be used with a star washer.
Remote +12VDC Ground
~
[ [POWER CONNECTORI I Front
0@[~J@~
Power Wire Requirements
The HD600/4's "+12 VDC" and "Ground"
connections are designed to accept 4 AWG power
wire. 4
AWG pure copper wire is recommended
for any power wire
run longer than 72 inches (180
cm). For runs shorter than 72 inches, 8 AWG pure
copper power wire
is acceptable.
If you are installing the HD600/4 with other
amplifiers
and wish to use asingle main power
wire, use 2
AWG or 1/0 AWG pure copper wire
as amain power wire. This 2 AWG or 1/0 AWG
power wire should terminate into adistribution
block mounted as close
to the amplifiers as
possible and should connect to the HD600/4 with
4
AWG or 8AWG pure copper power wire.
Please note that lower
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.).
+12V Battery Connection
You will need to connect apower wire to
the vehicle's positive battery terminal, using an
appropriate power ring or specialized battery
terminal connector, such
as the JL Audio
XB-BTU. This connection must be tight
and
corrosion-free to ensure proper connectivity. This
wire MUST be fused appropriately for safety. Any
positive power wires run through metal barriers
(such
as firewalls), must be protected with ahigh
quality insulating grommet to prevent damage to
the insulation
of the wire. Failure to do so may
result in adangerous short circuit.
6I JL Audio -HD600/4 Owner's Manual

DIMPORTANTI
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
pure copperwire when installing amplifier
systems with
main fuse ratings above 60A.
Turn-On Wire
The HD600/4 uses aconventional + 12V remote
turn-on wire, 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 offwhen + 12V is switched off. If
asource unit does not have adedicated remote
turn-on output, the amplifier's turn-on lead can
be connected to
+12V via aswitch that derives
power from an ignition-switched circuit.
The HD600/4's
"Remote" turn-on connector
is designed to accept 18 AWG - 12 AWG wire. 18
AWG is more than adequate for this purpose.
To connect the remote
turn-on wire to the
amplifier, first back out the set screw on the
bottom
of the Power Connector Plug, using the
supplied hex wrench. Strip
1/2 inch (l2mm) of
wire and insert the bare wire into the receptacle,
seating
it firmly so that no bare wire is exposed.
When using smaller wire, it may be necessary to
strip 1inch
of insulation from the wire and fold
the bare wire in halfprior to insertion. While
holding the wire in the terminal, tighten the
set screw firmly using the supplied 2.5
mm hex
wrench, taking care not to strip the head ofthe
screw and making sure that the wire
is firmly
gripped by the set screw.
Amplifier Power Connector Plug
To connect the power wires and the remote
turn-on wire to the amplifier, unplug the power
connector plug from the amplifier chassis (pull
back firmly) and back
out the set screws on
the connector plug, using the supplied 4
mm
hex wrench for the +12 VDC" and "Ground"
connections and the supplied 2.5 mm hex wrench
for the
"Remote" connection. Strip 3/8 inch (10
mm) of insulation from the end of each wire and
insert the bare wire into the receptacle on power
connector plug, seating
it firmly so that no bare
wire
is exposed. While holding each wire in place,
tighten each set screw
fi rmly, taking care not to
strip the head
of the screw.
DIMPORTANTI
Never make power connections with a"live"
wire. Always
disconnect the negative battery
post before making any connections or
adjustments to a12V power connection!
7

AMPLIFIER MOUNTING OPTIONS
The HD600/4 has two mounting options to
ease in installation.
Standard Mounting
,!.~ (9) /
'r!! /0////
T
I
The standard method of mounting requires
removal
of the four corner caps with the 3/16-inch
hex wrench included with your amplifier. Using
appropriate mounting screws (not included),
secure the amplifier in all four corners and
replace the corner caps.
Lateral Mounting Feet
CONTROL PANEL SECURITY COVER
The HD600/4 features aControl Panel Security
Cover.
When installed, the cover ensures that
your amplifier settings are not accidentally
changed while creating aclean aesthetic for the
amplifier and your installation. The control panel
security cover
is pre-installed at the factory and
must be temporarily removed for access to the
controls described throughout this manual.
The security cover
is secured by asingle 2.5
mm hex-head screw at the far right of the panel.
Loosen the hex-head screw to release the security
cover (it
is not necessary to completely remove the
screw).
To re-install the security cover once all
adjustments have been made, insert the tongue
on
the cover's left edge into the groove where the left-
side heatsink meets the control panel, hinge the
panel closed and secure the screw using the
supplied 2.5
mm hex wrench. Do not overtighten
the screw.
Lateral Mounting Feet are also included with
your HD600/4 to provide
an alternative mounting
option. Each mounting foot should be attached
to the bottom
of the amplifier by screwing the
provided bolt into the bottom
of the amplifier and
up into the corner cap with the supplied lI8-inch
hex wrench. Next, using appropriate mounting
screws (not included), secure the amplifier
by its
four Lateral Mounting Feet.
DIMPORTANT I
Checkbefore drilling any holes in your vehicle
to
make sure that you will not be drilling
through agas tank, brake line, wiring harness
or other vital vehicle system.
8I JL Audio -HD600/4 Owner's Manual

,ote
AMPLIFIER INPUTS
The HD600/4 has two separate input sections,
one for the "Front" left
and right channels and
another for the "Rear" left and right channels.
Each section consists
of apair of RCA-type input
jacks
on the Con nection Panel of the amplifier
and apair
of input controls on the Control Panel
of the amplifier: an "Input Voltage" switch and an
"Input Sens." rotary control.
F@,~@
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~ ~l@" @J @
"INPUT MODE" SWITCH
The Control Panel houses an "Input
Mode" switch located under the "General Setup"
heading. This switch allows operation of all four
amplifier channels with only one pair
of input
signals
or with independent front and rear input
signal pairs.
]
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To use separate inputs for the "Front" and
"Rear" amplifier sections, (in order to permit
front-to-rear fading, for example), select "4
Ch."
on the "Input Mode" switch. In this mode, you
must connect separate pairs
of input cables to the
"Front" and "Rear" amplifier inputs.
To operate all four channels of the HD600/4
with asingle
pair of stereo inputs, select the
"2 Ch." position on the "Input Mode"
switch and connect asingle pair of input
cables to the
"Front" input jacks only. In
this mode, the amplifier will route the
signals connected to the
"Front" inputs to
the Front and Rear amplifier channels.
CHANNEL CONTROL SECTIONS
Flanking the "General Setup" section
on the Control Panel
of the amplifer are
two sets
of identical controls: one for the
"Rear Channel Controls" (on the left side)
and one for the "Front Channel Controls"
of the amplifier (on the right side).
In each
of these sections you will find an
"Input Voltage" range switch and arotary
control labeled
"Input Sens." (Input Sensitivity).
These controls are designed to match the input
sensitivity
of the HD600/4 to the specific signal
source that
is feeding it and must be adjusted,
with care, following the procedures outlined in
this manual. Failure to make correct adjustments
can result in weak output, excessive distortion
and/or undesirable noise in the audio output of
the amplifier!
Note: The Channel Control sections also house
"Filter Mode", "Filter Slope" and "Filter Freq."
controls. These are crossover filter controls
and will be discussed in the next section of this
manual. This section will explain the Input
Controls only.
9

"Input Voltage" Switch
Awide range of signal input voltages can
be accommodated by each
of the HD600/4's
differential-balanced inputs (200mV -8V
RMS).
This wide range is split up into two sub-ranges,
accessible via the
"Input Voltage" switches located
in each input section
of the amplifier. Be aware
that each input section's
"Input Voltage" switch
will have to
be configured, regardless of how many
input cables are actually feeding the amplifier.
The "Low" position on each
"Input
Voltage" switch selects an input sensitivity
range between 200mV and 2V This means that
the
"Input Sens." rotary control will operate
within that voltage window. Ifyou are using
an aftermarket source unit, with preamp-level
outputs, this
is most likely the position that
you will use (regardless
of what voltage output
capability
is claimed by the source unit).
The
"High" position on each "Input Voltage"
switch selects
an input sensitivity range between
800mV and 8V This
is for use with speaker-level
outputs from source units
and small amplifiers
found in many OEM (factory-installed) systems.
To use speaker-level sources, splice the speaker
~)Utput wires of the source unit or small amplifier
onto apair
of RCA plugs for each input pair
or use the
JL Audio ECS Speaker Wire to RCA
adaptor (XB-CLRAIC2-SW).
DIMPORTANTI
The output of the amplifier decreases for a
given
input voltage when the "Input Range"
switch is placed
in the "High" position. The
output increases with the switch in the "Low"
position.
While this may sound counter-
intuitive, it is correct as described.
10 I JL Audio -HD600/4 Owner's Manual
"Input Sens." Control
Located next to the "Input Voltage" switch
in each input section
is arotary control labeled
"Input Sens.". Once the appropriate "Input
Voltage" range has been selected, this control
can
be used to match the source unit's output
voltage to the input stage
of each pair of amplifier
channels for maximum clean output. Rotating the
control clockwise will result in higher sensitivity
(louder for agiven input voltage). Rotating the
control counter-clockwise will result in lower
sensitivity (quieter for agiven input voltage).
To
properly set each pair of amplifier channels for
maximum clean output, please refer to Appendix
C(pages
18, 19) in this manual.
After using this procedure, you can then adjust
the relative level
of each channel pair by adjusting
the input sensitivity downward on either
or both
channel pairs, ifthey require 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 C(pages
18, 19). Doing so will result in
audible distortion and possible speaker damage.
Be aware that both "Input Sens." adjustments
will have to
be made, regardless of how many
input cables are feeding the amplifier. These
controls will allow you to set the appropriate
relative levels for the
"Front" channels relative
to the
"Rear" channels and any other amplifier
channels in the system.

:ONTROLS ---.J
-200 ILJ 1=-_
1) "Filter Mode" Control: this switch allows you
to configure the filter for that
Channel Pair
into one
of two fi Iter types.
"Off": Defeats the filter completely, allowing
the full range
of frequencies present at the
inputs to feed
that pair of channels. This
is useful for systems utilizing outboard
crossovers
or requiring full-range reproduction
from
that pair of channels.
Depending on the speaker system
and the
vehicle, different filter slopes may be required to
produce asmooth transition between the
sound
of different speakers in the system.
In high-pass mode, the
sharper "24dB" setting
will do abetter job
of protecting small speakers
with limited power handling. In low-pass
mode, the
"24dB" setting can also help by more
aggressively removing lower midrange
output
from asubwoofer system.
The shallower "12dB" octave setting
allows for more
output overlap between
the speakers being crossed over. In
many
cases, this will result in a smoother "blend"
or transition between speaker systems.
Experiment to find the slope
or combination
of slopes which best matches the acoustic
requirements
of your system.
"24dB": Configures the filter to attenuate
frequencies above
or below the selected
filter frequency at arate
of 24 dB per octave
(Linkwitz-Rileyalignment).
2) "Filter Slope" Control: This switch allows you
to select from two filter slopes.
"12dB": Configures the filter to attenuate
frequencies above
or below the selected
filter frequency at arate
of 12 dB per octave
(Butterworth alignment).
3)
"Filter Freq. (Hz)" Control:
This control selects the frequency at which the
filter begins to attenuate the signal
and refers
specifically to the frequency at which
output
has been attenuated by -3dB.
Off I HP I LP
Filter
Mode
12dB I24dB
Filter
Slope
;00
Iz)
CROSSOVER CONTROLS
Crossovers are groups of electronic filters
designed to control the frequency ranges
that each speaker in asystem will be tasked
with reproducing. Proper crossover setup
is
critical to sound quality and reliability.
The HD600/4 has two individual filters,
one for the
"Front" channels and the
other for the
"Rear" channels. Each can be
configured as ahigh-pass filter (attenuates low
frequencies)
or as alow-pass filter (attenuates
high frequencies). Additionally, the user can
select from ashallow (l2dB/octave) filter slope
or amore aggressive (24dB/octave) slope.
Each
Channel Control section contains
identical crossover filter controls.
"HP" (High-Pass): Configures the
CH 1&2 filter to attenuate frequencies
below the selected filter frequency.
Useful for connection
of component
speakers in abi-amplified system.
"LP" (Low-Pass): Attenuates frequencies
above the selected filter frequency.
Useful for connection
of subwoofer(s)
in abi-amplified system.
The filter frequency markings
surrounding this
rotary control are for reference purposes
and are
generally accurate to within 1/3 octave
or better. If
you would like to select the filter cutofffrequency
with ahigher level
of precision, consult the charts
in Appendix B(page
18) of this manual.
11

BI-AMPLIFIED SYSTEMS
Bi-amplified systems are defined as systems
in which separate amplifier channels drive low-
frequency
(LF) and high-frequency (HF) speakers
and are separately filtered to send appropriate
frequency ranges
to each speaker system.
The most common application
of
bi-amplification in mobile audio is to drive a
subwoofer system from one or more amplifiers or
channels and component speakers from separate
amplifiers or channels.
The HD600/4 can be configured to drive a
bi-amplified system by itselfor with aseparate
subwoofer amplifier.
Bi-Amplified System with one HD600/4
In this configuration, the "Rear" channels
of the HD600/4 will drive subwoofers
(stereo IS0W x 2
or bridged 300W x 1) with
low-pass filtering. The
"Front" channels
will drive component speakers in stereo
(IS0W x
2) with high-pass filtering.
Crossover Setup for Bi-Amplified System
with one HD600/4:
Once the input sections have been configured
appropriately,
go to the "Rear Channel Controls"
Section. Select "LP" (low-pass) on the "Filter
Mode" switch and "12dB" or "24dB" on the
"Filter Slope" switch and an appropriate "Filter
Freq." (80-90 Hz
is agood starting point).
Next,
turn your attention to the "Front
Channel Controls" Section. and select "HP"
(high-pass) on the "Filter Mode" switch and
"12dB"
or "24dB" on the "Filter Slope"
switch
and an appropriate "Filter Freq."
(again, 80-90 Hz
is agood starting point).
After proper adjustment
of the Front and
Rear channel
"Input Range" and "Input
Sens." controls using the method shown
in Appendix C(pages
18, 19), you can
fine
tune filter frequencies and slopes and
attenuate either pair
of channels to achieve
proper balance. For precise filter frequency
information refer to Appendix B(page
18).
12 I JL Audio -HD600/4 Owner's Manual
Bi-Amplified System with one
HD600/4 in four-channel mode and
aseparate subwoofer amplifier
This configuration requires that the
separate subwoofer amplifier has abuilt-in
low-pass filter. In this configuration, the
"Front" channels of the HD600/4 will drive
front component speakers (stereo IS0W x
2)
with high-pass filtering. The "Rear" channels
will drive rear component speakers in stereo
(IS0W x
2) with high-pass filtering.
The separate subwoofer amplifier will drive the
subwoofer system with low-pass filtering (select a
filter frequency
of 80-90 Hz to start). The inputs
of the subwoofer amplifier can be fed from the
HD600/4's preamp output
or from adedicated
subwoofer output on the source unit.
Crossover Setup for Bi-Amplified System with one
HD600/4 and aseparate subwoofer amplifier:
Once the input and preamp output sections
have been configured appropriately,
go to the
"Front Channel Controls" Section. Select "HP"
(high-pass) on the "Filter Mode" switch and
"12dB" or
"24dB" on the "Filter Slope" switch
and an appropriate "Filter Freq." (80-90
Hz is a
good starting point).
Next,
turn your attention to the "Rear
Channel Controls" Section and select "HP"
(high-pass) on the "Filter Mode" switch and
"12dB" or
"24dB" on the "Filter Slope" switch
and an appropriate
"Filter Freq." (again, 80-90 Hz
is agood starting point).
After proper adjustment
of the HD600/4's and
the subwoofer amplifier's
"Input Range" and
"Input Sens.", you can fine tune filter frequencies
and slopes and attenuate either
pair of channels
to achieve proper balance. For proper adjustment
of the "Input Sens." controls of the HD600/4 use
the method shown in Appendix C(pages
18, 19).
For precise filter frequency information for the
HD600/4 refer to Appendix B(pages
18). Refer to
the subwoofer amplifier owner's manual for its
proper adjustment levels.

PREAMP OUTPUTS
The HD600/4 incorporates apass-through
preamp output section, so that additional
amplifiers can easily be connected to the same
signal(s) feeding the HD600/4. These preamp
output signals are accessible via astereo pair
of RCA-type ja'Cks, labeled "Preouts", on the
Connection Panel.
@,I
Preouts RemOl
fA\ level
~ R Cont"
The term "pass-through" refers to the fact that
the Preamp Output signals are not affected by any
crossover filter or input sensitivity setting selected
on the HD600/4 (ifthe input signal is full-range,
the Preamp Output will be full-range). These
preamp output signals are buffered to prevent
noise and are always preamp level, regardless of
the level of signals feeding the HD600/4's inputs.
The pass-through Preamp Outputs can be
configured two different ways using the switch
labeled "Preouts From" in the "General Setup"
section of the Control Panel.
I [
3) "F+R" (Front +Rear): This mode delivers a
sum of the signals being fed to the "Front
Inputs" and the "Rear Inputs" of the
amplifier. When the HD600/4 is being used
to drive front and rear speaker systems, this
preamp output mode will deliver a summed
front/rear signal to the subwoofer amplifier,
while permitting fading of the front and rear
speaker systems from the source unit.
REMOTE LEVEL CONTROL (OPTIONAL)
With the addition of the optional Remote Level
Control (HD-RLC), you can control the volume
of one or both channel pairs of the HD600/4
from the front of the vehicle. This is useful for
subwoofer level control or even as amaster
volume control for the system.
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 HD amplifiers can be
controlled from asingle HD-RLC controller
using asimple phone line "splitter" and multiple
phone cables.
~,~"".~
Remote
~ Level 1
~ R Control ~
2 ch.14 Ch.
Input
Mode
All ch.1 Rear Ch.
Remote
level Control
Front 1F+R
Preouts
From
L- GENERAL SETUP -.l
10 HC600/4 Four-Channel Ar
1) "Front": The preamp output delivers the same
signal that is connected to the HD600/4's
"Front Inputs". This mode is useful for
feeding asubwoofer amplifier when the
HD600/4 is being used to drive front and rear
speaker systems. In this mode, the preamp
output level will track with the signal level
of the front input signals, allowing the user
to fade the rear channels in and out, without
affecting the subwoofer level.
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 alevel attenuator.
Depending on the application, you may want
the HD-RLC to only affect one channel pair or
both channel pairs. Aswitch labeled "Remote
Level Control" in the "General Setup" Section
of the Control Panel allows you to determine
whether the HD-RLC affects the level of all
channels "All Ch." or only the rear channels
"Rear Ch."
13

I-
,-
,-
2Ch.14Ch
All Ch.1 Rear Ch.
Front I F+R
Input
Remote Preouts
Mode Level Control
From
L- GENERAL SETUP --.J
liD. HDBOO/4 Four-Channel AI
For example, if you are using the HD600/4 in a
stand-alone bi-amplified mode, you may want the
HD-RLC to only affect the level
of the subwoofer
channels. Setting the
"Remote Level Control"
switch to the "Rear Ch." position accomplishes
this (provided the subwoofer system
is connected
to the rear channels).
In other cases, you may want control
of all
four channels
at the same time, so you would
set the "RemoteLevel
Control" switch to the
"All Ch." position.
14 I JL Audio -HD600/4 Owner's Manual
DIMPORTANTI
The RBC-I Remote Bass Control used with
JL Audio Slash, Slash v2, e-Series, A-Series and
G-Series amplifiers is NOT compatible with the
HD Series amplifiers. If you attempt to connect
an RBC-I to an HD amplifer, the control will
not work. You must use the HD-RLC controller.
SPEAKER OUTPUTS
The HD600/4 employs ]L Audio's exclusive
Regulated, Intelligent Power Supply (R.I.P.S.)
design.
The operation of the R.I.P.S. system is
independent for each pair of channels. This
sophisticated power supply allows the amplifier to
produce its
optimum power (ISO watts x 4) over a
wide range
of speaker impedances.
®
0(LJO 0l
R
JO 0l
L
lO 01RJO
[ fRONT SIPEAOCIEIR O!JT !REAR SI?EAKER OUT]
[tIIDJe~CID]
Unlike conventional amplifiers that require
aspecific impedance to produce
optimum
power, the R.I.P.S.-equipped HD600/4 gives
you the freedom to use avariety
of speaker
configurations
that achieve final nominal
impedances between 1.5 - 40 per channel in
stereo (without sacrificing power
output or sound
quality). When bridged, each channel pair will
optimize
output at 300 watts between 3 - SO.
The operation of the R.I.P.S. circuitry is
entirely automatic and adjusts itselfevery time the
amplifier
is turned on. There are no user controls
to configure. The system operates
through
multiple stages of impedance optimization,
choosing the stage
most appropriate to the actual
impedance
of the speakers you connect to it.

DIMPORTANTI
If you connect a load higher than 40 nominal
per channel in stereo mode (or 80 in bridged
mode), power will drop by half with every
doubling of impedance above 40 stereo 1 80
mono. If you connect a load lower than 1.50
nominal per channel in stereo mode (or 30 in
bridged mode, the amplifier protection
circuitry activates a"safe" mode which reduces
amplifier power to protect the circuitry from
failure (the LED status indicator on the control
panel will light up amber to indicate that this
has happened). See page 16 for details.
DIMPORTANTI
Speaker loads below 1.50 nominal per channel
in stereo or 30 nominal in bridged mode are
not recommended and may cause the amplifier
output to distort excessively.
BRIDGING CONSIDERATIONS
Bridging is the practice of combining the
output of two amplifier channels to drive asingle
load.
When bridged, each channel produces
signals
of equal magnitude, but opposite polarity.
The combined output of the two channels
provides twice the
output voltage available from a
single channel.
The HD600/4 has been designed
for bridging
of its channel pairs without the need
for input inversion adaptors.
ell). elRl. ell). e(R).
[fRONT SIP'IEAi<IER OUT REAIR SIP'IEAI<IEIR OllJf J
[aID]@[aID]
To bridge apair of channels, use the "Left +"
and "Right -" speaker connectors only
(the
"Left -" and "Right +" remain unused).
Then connect a
mono signal to both left and
right RCA inputs for that channel pair. This
requires
an RCA "Y-Adaptor" (sold separately),
because abridged
pair of channels requires that
both amplifier channels of the bridged pair
receive input. Connection of only one RCA input
will result in reduced power output, increased
distortion
and can cause the amplifier to overheat.
When bridged, each channel pair will
deliver
optimum power into a 3-80 load.
Operating bridged channel pairs into aload
lower
than 30 is not recommended.
Speaker Connector Plugs
To connect the speaker wires to the amplifier,
unplug the speaker connector plugs from the
amplifier chassis (pull back firmly)
and back out
the set screws on each connector plug, using the
supplied 2.0
mm hex wrench. Strip 3/8 inch (10
mm) of insulation from the end of each wire and
insert the bare wire into the receptacle on the
speaker connector plug, seating it firmly so that
no bare wire
is exposed. While holding each wire
in place, tighten each set screw firmly, taking care
not to strip the head
of the screw.
15

"STATUS" LED! PROTECTION CIRCUITRY
There is asingle multi-color LED on the
control panel of the amplifier to indicate the
amplifier's operating status. This LED's behavior
is as follows:
1) Flashing Green: 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. The red
light will turn green and the amplifier will
return to full-power operating mode when its
temperature returns to asafe level.
3) Constant Amber (yellow): lights to indicate
that the impedance of the speaker load
connected to the amplifier is lower than
the optimum load impedance range for the
amplifier. When this light is on, aprotection
circuit engages and reduces the power output
of the "Front" or the "Rear" channels,
depending on which channel is experiencing
the problem. The amber indicator will also
light when ashort-circuit is detected in the
speaker wiring (this can be a short between the
positive and negative speaker wires or between
either speaker wire and the vehicle chassis).
This can be used to diagnose ashort-circuit by
only connecting one of the amplifier sections
at a time ("Front" or "Rear" channels). The
amber LED will light when you connect the
section that is experiencing the problem and
turn the volume up.
16 I JL Audio -HD600/4 Owner's Manual
4) Alternating Red and Green: lights to indicate
that the amplifier is experiencing afault
that may require service of the amplifier, its
wiring or the vehicle's charging system. Audio
is muted when this fault occurs. The most
likely cause of this fault is alow supply voltage
condition. If battery voltage drops below 8.5
volts at any point, the amplifier (except for the
"Status" LED) will shut itself off to protect itself
and the vehicle's charging system. If the voltage
drops below 6volts, the "Status" LED will also
turn off.
The amplifier will turn back on automatically
when voltage climbs back above 9volts. This
shut-down and turn-on behavior may happen
in arapid cycle when bass-heavy program
material causes aweak charging system to
momentarily dip too low. Ifthis is happening
in your system, have your charging system
inspected to make sure it is working properly.
If no problem is found with the supply
voltage to the amplifier and you are
still seeing alternating Red and Green
on the "Status" LED, it is likely that the
amplifier is suffering from an internal
fault that requires factory service.
For more information on troubleshooting this
amplifier, refer to Appendix D(pages 20, 21).
There is only one condition that will shut down
an undamaged HD600!4 completely ...
If battery voltage drops below 10 volts, the
entire amplifier will shut itself off to protect
itself and the vehicle's charging system. The
"Status" LED will turn off when this occurs. The
amplifier will turn back on when voltage climbs
back above 11 volts. This may happen in arapid
cycle when bass-heavy program material causes
aweak charging system to dip below 10 volts
momentarily. If this is happening in your system,
have your charging system inspected to make
sure it is working properly. For information on
troubleshooting this amplifier, refer to Appendix
D(pages 20, 21).

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.
Jl Audio Technical Support:
[phone]
9:00 AM -5:30
PM (Eastern Time Zone)
Monday -Friday
APPENDIX A:
HD600/4 Specifications
Amplifier Topology: Class D, switching type with
patented Single-Cycle Control'M technology.
Power Supply: Pulse width modulation-regulated
switching
power supply
Recommended Fuse Value /Type: SOA (AFS, AGU or
MaxiFuse'M)
Rated Power (Stereo):
1S0W RMS x4@ 15-40 (llV -145V)
Rated
Power (Bridged):
300W
RMS x 2 @ 3-80 (11V - 14.SV)
THD at Rated Power: <003% @ 40 per channel
(Average at 1
kHz)
Signal to Noise Ratio (20 kHz Bandwidth):
Referred to Rated Power: 110 dBA
Referred
to 1Watt: 88.2 dBA
Frequency Response: 6 Hz - 30 kHz (+0, -1 dB)
Damping Factor:
300 @
40 per ch. /50 Hz
150 @ 20 per ch. /50 Hz
Crossover Filters:
Filter Sets: Two (Front Channel and Rear Channel)
Filter Type: State-variable, 12 dB/octave Butterworth or
24 dB/octave Linkwitz-Riley
Filter
Modes: Low-Pass or High-Pass, Defeatable.
Cutoff Freq. Range: Continuously variable, 50 -500 Hz
Input Sections:
No. of Inputs: Two Stereo Pairs (Front and Rear)
Input Type: Differential-balanced with RCA Jack inputs
Input Range: Switchable from 200mV - 2V RMS (Low)
to 800mV - 8V RMS (High)
Preamp Output:
2-Channel. buffered pass-through type, switch-selectable
to pass signal from "Front" inputs only, or from all four
inputs (summed).
Chassis Dimensions (LxWxH):
10.74 in. x785 in. x 1.03 ill. ,::'73 mm x1905 mm x49 mm)
Dimellslons do not include connectors.
[}lIe 10 <'ll(li,J!!lq orodu( r devt'IO~\lllt:nl .~il :'L~t'(;ri( j~I\'~' ".~ ,~re :"ul::,:e_ t !o
It'(~I\lt' '\'It~ ~ULJt "oll(':t:
17

APPENDIXB:
Precise FrequencySelection Chart
"FILTER FREQ"
Detent Panel Actual
Number Marking Freq.
Full counter-clockwise: 58
01 53
02 "50". ..53
03 .53
04 .53
05.. ..54
06............... .56
07. ..58
08 "60" 60
09. .62
10 64
11 ..66
12 68
13 .71
14.. .74
15.. .76
16 "80".. ..80
17.......... 83
18.. . .87
19 91
20... .. 94
21 99
22 .. 104
23 .. 109
24 "120" .. 115
25............... .121
26 128
27 .137
28......... .147
29...... 160
30............ ..174
31 ... 191
32 ... "200" .. 211
33.. ... 236
34 .. .. .. 269
35 .
.. 309
36 .
.. 369
37
..... 443
38 "500"
.. 484
39.. .525
Full-clockwise: 528
18 I JL Audio -HD600/4 Owner's Manual
APPENDIXC:
Input Sensitivity Level Setting
JL Audio amplifiers utilizing the Regulated
Intelligent
Power Supply (R.LP.S.) allow
delivery of their rated power when connected
to any load impedance from 1.5 - 40 per
channel and when connected to a charging
system with any voltage from 11 -14.SV
This design is beneficial for many reasons.
One of these reasons is ease of setup.
Because each JL Audio amplifier will
always deliver
the same amount of power
within its operational range of impedances
and supply voltages, the maximum,
undipped output is very predictable.
This makes setting the gain structure via the
input sensitivity controls very simple. Following
the directions below will allow the user to adjust
the input sensitivity of the amplifier(s) simply
and easily in just afew minutes using equipment
which is commonly available in installation bays.
Necessary Equipment
•Digital AC Voltmeter
• CD with asine-wave test tone recorded at
odB 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). The CleanSweep@
Calibration Disc contains the appropriate
test tones and is available for sale at
http://store.jlaudio.com Do not use attenuated
test tones (-10 dB, -20 dB, etc.).
DIMPORTANTI
Do not increase any "Input Sens." setting 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, source unit tone controls or EQ
circuits. EQ cuts will not require re-adjustment.

The Nine-Step Procedure
(follow this procedure for each pair of channels)
1) Disconnect the Speaker Connector Plugs.
2) Turn off all processing on the source unit
(bass/treble, loudness, EQ, etc.). Set fader
control to center position
and subwoofer
level control to 3/4
of maximum (if
used to drive the HD600/4). Disconnect
the HD-RLC Remote Level Control
temporarily (ifone
is being used).
3) Switch the "Input Voltage" to "Low" and
turn the "Input Sens." control on both sets of
channels all the way down.
4) Set the source unit volume to 3/4
of full
volume.
If either set of channels is being
driven by asource unit's dedicated subwoofer
output, also adjust the source unit's subwoofer
level control to 3/4
of maximum output. This
will allow for reasonable gain overlap with
moderate clipping at full volume.
S) Using the chart below, determine the
target voltage for input sensitivity
adjustment according to the nominal
impedance
of the speaker system
connected to each set
of outputs.
6) Verify
that you have disconnected the Speaker
Connector Plugs before proceeding. Playa
track with an appropriate sine wave (within the
frequency range to be amplified by each set
of
channels) at 3/4 source unit volume.
7)
Connect the AC voltmeter to the "Front
Speaker Outputs" or "Rear Speaker Outputs"
connectors of the amplifier. If the channel pair
is operating in stereo, it is only necessary to
measure one channel in the pair. Ifbridged,
make sure you test the voltage at the correct
connectors
(L+ and R-).
8) Increase the
"Input Sens." control until
the target voltage
is delivered for that set
of channels. If excessive voltage is read
on either set
of channels with the control
at
minimum (full counterclockwise),
switch the appropriate
"Input Voltage"
switch to
"High" and re-adjust.
9) Once you have adjusted each set
of channels to
its
maximum unclipped output level, reconnect
the speaker(s). The "Input Sens." controls can
now be adjusted downward if either or both
sets
of channels requires attenuation to achieve
the desired system balance.
Nom.
Impedance
SO 24.5 V 49.QV 24.5 V 49.QV
60 24.5 V 42.4 V 24.5 V 42.4 V
40 24.5 V 34.6 V 24.5 V34.6V
30
21.2V 3Q.QV 21.2V 3Q.QV
20
17.3 Vnot recommended
17.3 Vnotrecommended
1.S0 15.QV
not recommended
15.QV
not recommended
19

APPENDIX D: TROUBLESHOOTING
"How do Iproperly set the input sensitivity on myamplifier"
Please refer to Appendix C(pages 18, 19) to set the input sensitivity
for
maximum, low-distortion output.
"My amplifier doesn't turn on"
Check the fuse(s), not just visually, but with acontinuity meter. It
is possible for afuse 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.
Checkto 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 arelay
is required. To test for this problem, jump the "+12VDC" wire
to the "Remote" terminal to see ifthe amplifier turns on.
"I get adistorted /attenuated sound coming out of the speaker(s)"
Check the speaker wires for apossible short, either between the
positive
and negative leads or between either speaker lead
and the vehicle's chassis ground. If ashort 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 adifferent set of wires connected to atest
speaker.
Check the nominal load impedance to verify that each channel
of the amplifier is driving aload equal to or greater than
1.5 ohms in stereo mode (3 ohms bridged).
Check the input signal and input signal cables to make sure signal
is present at the "Amplifier Inputs" and the cables are not
pinched
or loose. It may be helpful to try adifferent set of
cables and/or adifferent signal source to be sure.
"My amplifier's outputfluctuates when I tap on it or hit abump"
Check the connections to the amplifier. Make sure that the
insulation for all wires has been stripped back far enough to
allow agood contact area inside the connector plugs.
Check the input connectors to ensure that they all are making good
contact with the input jacks on the amplifier.
20 IJLAudio -HD600/4 Owner's Manual