JL Audio Car Amplifier HD900 5 User Manual

owner’s manual  
5-Channel Class-D System Amplifier  
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 the JL Audio Technical Support Department  
at (954) 443-1100 during business hours.  
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cooling efficiency considerations:  
Your JL Audio amplifier employs an  
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.  
advanced type of heat management, called  
RealSink™. 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 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.  
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.  
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.  
Filter Slope  
Selection  
(pg. 11)  
Filter Frequency  
Selector  
(pg. 10)  
Input Mode  
Selection  
(pg. 9)  
quency  
ctor  
11)  
Input Sensitivity  
Control  
(pg. 10)  
Filter Slope  
Selection  
(pg. 11)  
Input Voltage  
Selection  
(pg. 9)  
Speaker Outputs  
(pgs. 13-14)  
3
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Product descriPtion  
The JL Audio HD900/5 is a very powerful  
and compact five-channel amplifier utilizing  
patented Single Cycle Control™ Class D  
technology for all channels. This groundbreaking  
technology delivers reference-grade, full-  
range sonic performance while requiring  
far less current from the vehicle’s electrical  
system than a conventional amplifier.  
The HD900/5’s flexible input and crossover  
sections permit operation with a wide variety  
of source units and system configurations.  
It can be operated with a single pair of  
stereo inputs, with two pairs of stereo inputs  
(front and rear) or with separate inputs for  
its front, rear and subwoofer channels.  
JL Audio’s exclusive R.I.P.S. power supply  
design optimizes the output of each channel  
section for any impedance between 1.5 and 4  
ohms per channel (3-8 ohms bridged on front and  
rear sections) allowing you to get full use of the  
HD900/5’s performance capabilities with a wide  
range of speaker systems.  
As we said, it’s very flexible.  
The tightly regulated power supply design also  
means that the HD900/5’s clean power output  
capability remains stable over a wide range of  
vehicle voltages, resulting in enhanced fidelity.  
The HD900/5 flexible, studio-grade signal  
processing allows it to be deployed in several  
different system configurations:  
1) As a five-channel amplifier in a bi-amplified  
system, driving four satellite speakers (100W x  
4), plus a subwoofer system (500W x 1).  
2) As a very powerful three-channel amplifier  
in a bi-amplified system, driving two satellite  
speakers (150W x 2, bridged), plus a subwoofer  
system (500W x 1).  
3) As a five-channel amplifier in a tri-amplified  
system, driving two tweeters (100W x 2), plus  
two woofer/mids (100W x 2), plus a subwoofer  
system (500W x 1). An external 2-way  
crossover is required for this application.  
4 | JL Audio - HD900/5 Owner’s Manual  
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tYPical installation sequence  
The following represents the sequence for  
a typical amplifier installation, using an  
aftermarket source unit or OEM Interface  
processor (like the CleanSweep® CL441dsp).  
Additional steps and different procedures may  
be required in some applications. If you have  
any questions, please contact your authorized  
JL Audio dealer for assistance.  
1) Disconnect the negative battery post  
connection and secure the disconnected cable  
to prevent accidental re-connection during  
installation. This step is not optional!  
2) Run 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. 4 AWG is the  
minimum recommended wire size for  
this amplifier. Use a 2 AWG or 1/0 AWG  
main power wire with a power distribution  
block when additional amplifiers are being  
installed with the HD900/5 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.  
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 (60A for a  
single HD900/5) and reconnect the negative  
battery post terminal.  
13) 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.  
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.  
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 a good, solid, bare metal grounding  
point close to the amplifier and connect the  
negative power wire to it using appropriate  
hardware. Use minimum 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 8 for detailed  
mounting instructions).  
5
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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.  
We do not recommend the use of “copper-clad  
aluminum wire” or “CCA” wire because this  
wire is significantly less conductive than pure  
copper wire. Only use pure copper power wire,  
such as JL Audio’s MetaWire™. 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 a fuse on the main 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 a collision  
or short-circuit. The fuse value at each power  
wire should be just high enough for all of the  
equipment being run from that power wire. Do  
not use a fuse with a value that far exceeds the  
total fuse rating of the electronics connected to  
the wire.  
If only the HD900/5 is being run from  
a single power wire, install a 60A fuse to  
protect the wire: 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  
a main power wire and exceed 80 amps in total  
fuse rating, we recommend the use of an ANL  
(large-blade) fuse and holder. Each amplifier can  
then be fused independently at the outputs of  
the power distribution block. Use JL Audio part  
XC-FOA-2PAK and appropriate MaxiFuse™ type  
fuses with JL Audio distribution blocks.  
Please consult with your JL Audio  
+12V battery connection  
You will need to connect a power 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 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.  
Power wire requirements  
The HD900/5’s “+12 VDC” and “Ground”  
connections are designed to accept 4 AWG  
power wire. 4 AWG pure copper wire is  
the minimum recommended wire size for  
this amplifier. Use of smaller gauge wire  
(including cheap wire that is fraudulently sold  
as 4 AWG wire) can create a fire hazard.  
If you are installing the HD900/5 with other  
amplifiers and wish to use a single main power  
wire, use 2 AWG or 1/0 AWG pure copper wire  
as a main power wire. This 2 AWG or 1/0 AWG  
power wire should terminate into a distribution  
block mounted as close to the amplifiers as  
possible and should connect to the HD900/5  
with 4 AWG pure copper power wire, with  
each smaller wire fused appropriately for each  
amplifier or other electronics in the system.  
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.).  
dealer to make sure that the wire, fuse  
holder and fuse ratings are appropriate  
for your system’s needs. The safety of  
your installation depends on appropriate  
power connections and fuse protection.  
ground connection  
The chassis ground connection must be made  
using 4 AWG pure copper wire and should be  
kept as short as possible, while accessing a solid  
piece of sheet metal in the vehicle. The surface of  
the sheet metal should be sanded at the contact  
point to create a clean, metal-to-metal connection  
between the chassis and the termination of the  
ground wire with a brass or copper power ring.  
6 | JL Audio - HD900/5 Owner’s Manual  
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amplifier Power connector Plug  
For optimal grounding, we recommend the  
use of a JL Audio ECS master ground lug  
(XB-MGLU). Alternatively, a sheet metal  
screw or bolt can be used with a star washer.  
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 firmly, taking care not to  
strip the head of the screw.  
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 copper wire when installing amplifier  
systems with main fuse ratings above 60A.  
turn-on wire  
The HD900/5 uses a conventional +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 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 HD900/5’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 (12mm) 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 1 inch of insulation from the wire and fold  
the bare wire in half prior 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 of the  
screw and making sure that the wire is firmly  
gripped by the set screw.  
Never make power connections with a “live”  
wire. Always disconnect the negative battery  
post before making any connections or  
adjustments to a 12V power connection!  
7
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amPliFier mounting oPtions  
The HD900/5 has two mounting options to  
ease in installation.  
control Panel securitY coVer  
The HD900/5 features a Control Panel  
Security Cover. When installed, the cover ensures  
that your amplifier settings are not accidentally  
changed while creating a clean 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.  
standard mounting  
The security cover is secured by a single 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.  
The standard method of mounting requires  
removal of the four corner caps with the 4 mm  
hex wrench included with your amplifier. Using  
appropriate mounting screws (not included),  
secure the amplifier in all four corners and  
replace the corner caps to cover the screws.  
lateral mounting Feet  
Lateral Mounting Feet are also included with  
your HD900/5 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 2.5 mm  
hex wrench. Next, using appropriate mounting  
screws (not included), secure the amplifier by its  
four Lateral Mounting Feet.  
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.  
8 | JL Audio - HD900/5 Owner’s Manual  
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amPliFier inPuts  
“4 ch.” input mode  
The HD900/5 has three separate input sections,  
one for the “Front” left and right channels,  
another for the “Rear” left and right channels  
and one for the Subwoofer Channel. Each section  
consists of a pair of RCA-type input jacks on  
the Connection Panel of the amplifier and input  
controls on the Control Panel of the amplifier: a  
single “Input Voltage” switch, an “Input Mode”  
switch and three individual “Input Sens.” rotary  
controls (one in each channel section).  
In this mode, you will connect separate  
pairs of input cables to the “Front” and “Rear”  
amplifier inputs and leave the “Sub” inputs  
unused. The subwoofer channels will receive  
signal from the sum of the signals at the “Front”  
and “Rear” inputs so that front-to-rear fading of  
the main channels does not significantly affect  
the subwoofer level.  
“2 ch.” input mode  
To operate all five channels of the HD900/5  
with a single pair of stereo inputs, select the  
“2 Ch.” position on the “Input Mode” switch  
and connect a single pair of input cables to  
the “Front” input jacks only. The “Rear”  
and “Sub” input jacks will remain unused.  
In this mode, the amplifier will route the  
signals connected to the “Front” inputs to  
the Front, Rear and Subwoofer channels.  
Front-to-rear fading will not be available.  
“inPut mode” switcH  
“input Voltage” switch  
The “Input Mode” switch is located under  
the “General Setup” heading at the far right of  
the control panel. This switch allows operation  
of all five amplifier channels with only one pair  
of input signals (2 ch.) or with independent front  
and rear input signal pairs (4 ch.) or with discrete  
front, rear and subwoofer signal pairs (6 ch.).  
A wide range of signal input voltages can be  
accommodated by each of the HD900/5’s differential-  
balanced inputs (200mV – 8V RMS). This wide range  
is split up into two sub-ranges, accessible via the  
“Input Voltage” switch located next to the “Input  
Mode” switch under the “General Setup” heading.  
The “Low” position of the “Input Voltage”  
switch selects an input sensitivity range between  
200mV and 2V for all the amplifier channels. This  
means that the “Input Sens.” rotary controls will  
operate within that voltage window. If you 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 of the “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  
output wires of the source unit or small amplifier  
onto a pair of RCA plugs for each input pair or use  
the JL Audio ECS Speaker Wire to RCA adaptor  
(XB-CLRAIC2-SW). It is not necessary (or  
advisable) to use “Line Output Converters” with  
your HD900/5.  
“6 ch.” input mode  
In this mode, you will connect separate pairs  
of input cables to the “Front”, “Rear” and “Sub”  
amplifier inputs, allowing you full channel  
control from the source unit. If the source unit  
only provides a mono (single) subwoofer output,  
use a y-adaptor cable to feed both the “Left” and  
“Right” subwoofer inputs of the HD900/5 with  
the mono signal. Failure to do so will result in  
reduced gain and possible distortion.  
9
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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.  
for maximum clean output. Rotating the control  
clockwise will result in higher sensitivity (louder  
for a given input voltage). Rotating the control  
counter-clockwise will result in lower sensitivity  
(quieter for a given input voltage). To properly  
set each pair of amplifier channels for maximum  
clean output, please refer to Appendix C (pages  
18, 19) in this manual.  
cHannel control sections  
After using this procedure, you can then adjust  
the relative level of each channel pair by adjusting  
the input sensitivity downward on any of the  
channel sections, if they require attenuation to  
achieve the desired system balance.  
Do not increase the “Input Sens.” setting for  
any amplifier or channel section 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.  
To the left of the “General Setup” section on  
the Control Panel of the amplifer are three sets of  
controls: one for the “Rear Channel Controls”  
one for the “Front Channel Controls” and  
one for the “Subwoofer Channel Controls”.  
In each of these sections you will find a  
rotary control labeled “Input Sens.” (Input  
Sensitivity). These controls are designed to match  
the input sensitivity of each channel section of  
the HD900/5 to the specific signal source that  
is feeding the amplifier. These controls 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  
“High-Filter” or “Low-Pass Filter” 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.  
Be aware that all three “Input Sens.”  
adjustments will need 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 the  
“Sub” channel (and any other amplifier channels  
in the system).  
crossoVer controls  
Crossovers are groups of electronic filters  
designed to control the frequency ranges  
that each speaker in a system will be tasked  
with reproducing. Proper crossover setup is  
critical to sound quality and reliability.  
“input sens.” controls  
Once the appropriate “Input Voltage” range  
has been selected in the “General Setup” section  
of the amplifier, the “Input Sens.” controls are  
used to match the source unit’s output voltage to  
the input stage of each pair of amplifier channels  
The HD900/5 has three individually adjustable  
filter controls, one for the “Front” channels,  
one for the “Rear” channels and another for the  
“Sub” channel. The “Front” and “Rear” filters are  
high-pass filters (they attenuate low frequencies),  
10 | JL Audio - HD900/5 Owner’s Manual  
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while the “Sub” channel filter is a low-pass filter  
(attenuates high frequencies). For each filter, the  
user can select from a shallow (12dB/octave) filter  
slope or a more aggressive (24dB/octave) slope.  
Experiment to find the slope or combination  
of slopes which best matches the acoustic  
requirements of your system.  
2) “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.  
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 cutoff frequency  
with a higher level of precision, consult the charts  
in Appendix B (page 18) of this manual.  
1) “High-Pass Filter” Controls (Front and Rear  
channels) or “Low-Pass Filter” Control (Sub  
Channel): These switches allow you to select filter  
slopes or defeat the filter(s) completely.  
“80 Hz” is a good starting point for most systems  
where a subwoofer is connected to the Subwoofer  
Channel and component systems or coaxials to  
the four main channels.  
“Off”: Defeats the filter completely. Useful when  
using an external crossover, such as one built into  
a head unit or signal processor.  
inFrasonic Filter (subwoofer ch. only)  
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.  
“ 12dB”: Configures the filter to attenuate  
frequencies above or below the selected  
filter frequency at a rate of 12 dB per octave  
(Butterworth alignment).  
“ 24dB”: Configures the filter to attenuate  
frequencies above or below the selected filter  
frequency at a rate of 24 dB per octave (Linkwitz-  
Riley alignment).  
Depending on the speaker system and the  
vehicle, different filter slopes may be required to  
produce a smooth transition between the sound  
of different speakers in the system.  
In high-pass mode, the sharper “24dB” setting  
will do a better 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 a subwoofer system.  
With ported enclosures, the use of the  
“Infrasonic Filter” is highly recommended to  
protect the speaker(s) from excessive excursion  
below box tuning.  
With sealed enclosures, the use of the filter  
is less necessary, but can still help protect the  
speaker system from excessive excursion.  
The “Infrasonic Filter” can be completely  
defeated by selecting the “Off” position on its  
switch. This bypasses all signal from flowing  
through the circuit.  
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.  
11  
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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.  
bi-amplified system with one Hd900/5  
driving two main speakers plus subwoofer  
(3-channel mode)  
In this configuration, the “Front” channels  
of the HD900/5 will be bridged to drive the  
left front component speaker system (150W x  
1 @ 4Ω) with high-pass filtering. The “Rear”  
channels will be bridged to drive the right front  
component speaker system (150W x 1 @ 4Ω),  
also with high-pass filtering. The “Subwoofer”  
channel will drive the subwoofer system  
(500W x 1 @ 1.5-4Ω) with low-pass filtering.  
For information on proper bridging  
techniques refer to the section titled “Bridging  
Considerations” in this manual (page 14).  
Once the input sections have been configured  
appropriately, go to the “Front Channel  
Controls” Section. Select “12dB” or “24dB”  
on the “High-Pass Filter” and an appropriate  
“Filter Freq.” (80-90 Hz is a good starting point).  
Next, turn your attention to the “Rear  
Channel Controls” section and set it exactly the  
same as you set the “Front Channel Controls”.  
Finally, in the “Subwoofer Channel  
Controls” section, select “12dB” or  
“24dB” on the “Low-Pass Filter” switch  
and a “Filter Freq.” of 80-90 Hz.  
After proper adjustment of the HD900/5’s  
“Input Range” and “Input Sens.” controls,  
you can fine tune filter frequencies and  
slopes and attenuate each channel section to  
achieve proper balance. Keep in mind that  
the left and right front speakers will have  
independent “Input Sens.” controls in this  
configuration, and these need to be carefully  
matched for proper stereo performance.  
The HD900/5 can be easily configured to drive  
a complete bi-amplified system consisting of a  
subwoofer and four main speakers or a subwoofer  
and two main speakers.  
bi-amplified system with one Hd900/5  
driving four main speakers plus subwoofer  
(5-channel mode)  
In this configuration, the “Front” channels  
of the HD900/5 will drive front component  
speakers (stereo 100W x 2 @ 4Ω) with high-  
pass filtering. The “Rear” channels will drive  
rear component speakers in stereo (100W x 2  
@ 4Ω) with high-pass filtering. The subwoofer  
channel will drive the subwoofer system  
(500W x 1 @ 1.5-4Ω) with low-pass filtering.  
Once the input sections have been configured  
appropriately, go to the “Front Channel  
Controls” Section. Select “12dB” or “24dB” on  
the “High-Pass Filter” 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 “12dB”  
or “24dB” “High-Pass Filter” switch and an  
appropriate “Filter Freq.” (again, 80-90 Hz is a  
good starting point).  
Finally, in the “Subwoofer Channel  
Controls” Section, select “12dB” or  
“24dB” on the “Low-Pass Filter” Switch  
and a “Filter Freq.” of 80-90 Hz.  
After proper adjustment of the HD900/5’s  
“Input Range” and “Input Sens.” controls,  
you can fine tune filter frequencies  
and slopes and attenuate each channel  
section to achieve proper balance.  
12 | JL Audio - HD900/5 Owner’s Manual  
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remote leVel control (oPtional)  
With the addition of the optional Remote Level  
Control (HD-RLC), you can control the level of  
the Subwoofer Channel of the HD900/5 from  
the front of the vehicle. The HD-RLC connects  
to the jack labeled “Remote Level Control” on  
the Connection Panel of the amplifier using  
a standard telephone cable (supplied with the  
HD-RLC).  
sPeaker outPuts  
The HD900/5 employs JL 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 channel section. This  
sophisticated power supply allows the amplifier to  
produce its optimum power into higher  
impedances as well as low impedances.  
If desired, multiple HD amplifiers can be  
controlled from a single HD-RLC controller  
using a simple phone line “splitter”  
and multiple phone cables.  
The R.I.P.S.-equipped HD900/5 gives  
you the freedom to use a variety of speaker  
configurations that achieve final nominal  
impedances between 1.5 – 4Ω per channel  
in stereo while maintaining 75 - 100W x 4  
of clean power output. When bridged, each  
main channel pair will optimize output at  
150-200 watts between 3 – 8Ω. The mono  
subwoofer channel will deliver its full 500W  
output into any impedance between 1.5-4Ω.  
The operation of the R.I.P.S. circuitry is  
entirely automatic and adjusts itself every 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.  
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.  
When no HD-RLC is connected, the Level  
Control circuit is defeated.  
The RBC-1 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-1 to an HD amplifer, the control will  
not work. You must use the HD-RLC controller.  
If you connect a load higher than 4Ω nominal  
per channel in stereo mode (or 8Ω in bridged  
mode), power will drop by half with every  
doubling of impedance above 4Ω stereo / 8Ω  
mono. If you connect a load lower than 1.5Ω  
nominal per channel in stereo mode (or 3Ω 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 15 for details.  
13  
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bridging considerations  
speaker connector Plugs  
Bridging is the practice of combining the  
output of two amplifier channels to drive a single  
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 HD900/5 has been designed  
for bridging of its two main channel pairs without  
the need for input inversion adaptors.  
There are three speaker connector plugs on the  
HD900/5: one for the front channels, one for the  
rear channels and one for the subwoofer channel.  
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 2.5 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.  
The mono subwoofer channel cannot be  
bridged to another mono channel.  
To bridge either pair of main 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 a bridged 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.  
Speaker loads below 1.5Ω nominal per channel  
in stereo or 3Ω nominal in bridged mode are  
not recommended and may cause the amplifier  
output to distort excessively.  
When bridged, each channel pair will  
deliver optimum power into a 3-8Ω load.  
Operating bridged channel pairs into a load  
lower than 3Ω is not recommended.  
14 | JL Audio - HD900/5 Owner’s Manual  
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“status” led / Protection circuitrY  
There is a single multi-color LED on the  
control panel of the amplifier to indicate the  
amplifier’s operating status. This LED’s behavior  
is as follows:  
4) Alternating Red and Green: lights to indicate  
that the amplifier is experiencing a fault  
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 a low 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  
Remote Turn-On voltage drops below 6 volts,  
the “Status” LED will also turn off.  
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 temporarily 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 a safe level.  
The amplifier will turn back on automatically  
when voltage climbs back above 9 volts. This  
shut-down and turn-on behavior may happen  
in a rapid cycle when bass-heavy program  
material causes a weak charging system to  
momentarily dip too low. If this is happening  
in your system, have your charging system  
inspected to make sure it is working properly.  
3) Constant Amber (yellow): lights to indicate  
that at least one channel is in overcurrent  
protection mode. This could mean 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, a protection circuit engages and  
reduces the power output of the channel(s)  
experiencing the problem. This can manifest  
itself as audible distortion.  
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, check that there are no short-circuits to  
chassis ground in any of the speaker wiring  
in the vehicle. Disconnect speaker connectors  
from the amplifier one-by-one to check.  
If no problem is found with the supply or  
remote voltage, disconnect everything except  
power/ground/remote. If the amplifier is then  
turned on and displays an alternating red-  
green, the amplifier needs service.  
The amber indicator will also light when  
a short-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 a  
short-circuit by only connecting one of the  
amplifier sections at a time (“Front” or  
“Rear” or “Sub” channels). The amber LED  
will light when you connect the section that  
is experiencing the problem and turn the  
volume up. Note that a short in the speaker  
wiring may show an alternating red/green  
status light with no signal (volume down).  
For more information on troubleshooting this  
amplifier, refer to Appendix D (pages 20, 21).  
15  
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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:  
(954) 443-1100  
9:00 AM – 5:30 PM (Eastern Time Zone)  
Monday - Friday  
16 | JL Audio - HD900/5 Owner’s Manual  
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aPPendix a:  
Hd900/5 specifications  
Amplifier Topology: Class D, switching type with  
patented Single-Cycle Control™ technology.  
Power Supply: Pulse width modulation-regulated  
switching power supply  
Recommended Fuse Value / Type: 60A (AFS, AGU or  
MaxiFuse™)  
Rated Power (Main Channels / Stereo):  
100W RMS x 4 @ 4Ω (11V - 14.5V)  
75W RMS x 4 @ 1.5-3Ω (11V - 14.5V)  
Rated Power (Main Channels / Bridged):  
200W RMS x 2 @ 8Ω (11V - 14.5V)  
150W RMS x 2 @ 3-6Ω (11V - 14.5V)  
Rated Power (Subwoofer Channel):  
500W RMS x 1 @ 1.5-4Ω (11V - 14.5V)  
THD at Rated Power:  
Main Channels: <0.03% @ 4Ω per channel  
Subwoofer Channel: <0.05% @ 4Ω  
(Average at 1 kHz)  
Signal to Noise Ratio (20 kHz Bandwidth):  
Referred to Rated Power: 108 dBA  
Referred to 1 Watt: 88 dBA  
Frequency Response (Main Channels):  
12 Hz - 28 kHz (+0, -1dB)  
Frequency Response (Subwoofer Channel):  
12 Hz - 10 kHz (+0, -1dB)  
Damping Factor (Main Channels):  
>400 @ 4Ω per ch. / 50 Hz  
>200 @ 2Ω per ch. / 50 Hz  
Damping Factor (Subwoofer Channel):  
>800 @ 4Ω / 50 Hz  
>400 @ 2Ω / 50 Hz  
crossover Filters:  
High-Pass Filters: Front Channels and Rear Channels  
Low-Pass Filter: Subwoofer Channel  
Filter Type (all channels): 12 dB/octave Butterworth or  
24 dB/octave Linkwitz-Riley  
Cutoff Freq. Range: Continuously variable, 50 - 500 Hz  
input sections:  
No. of Inputs: Three Stereo Pairs (Front, Rear and Sub)  
Input Type: Differential-balanced with RCA jack inputs  
Input Range: Switchable from 200mV - 2V RMS (Low)  
to 800mV - 8V RMS (High)  
chassis dimensions (lxwxH):  
10.74 in. x 7.85 in. x 1.93 in. (273 mm x 199.5 mm x 49 mm)  
Due to ongoing product development, all specifications are subject to  
change without notice.  
Dimensions do not include connectors.  
17  
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aPPendix b:  
aPPendix c:  
Precise Frequency selection chart  
input sensitivity level setting  
JL Audio amplifiers utilizing the Regulated  
Intelligent Power Supply (R.I.P.S.) allow  
delivery of their rated power when connected  
to any load impedance from 1.5 - 4Ω per  
channel and when connected to a charging  
system with any voltage from 11 - 14.5V.  
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 supply voltages, the  
maximum, unclipped 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 a few minutes using equipment  
which is commonly available in installation bays.  
“Filter Freq”  
Panel  
marking  
detent  
number  
actual  
Freq. (Hz)  
Full counter-clockwise: 53  
01 . . . . . . . . . . . “50” . . . . . . . . . . . .53  
02 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53  
03 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53  
04 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53  
05 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54  
06 . . . . . . . . . . . . . . . . . . . . . . . . . . . .55  
07 . . . . . . . . . . . . . . . . . . . . . . . . . . . .57  
08 . . . . . . . . . . . . . . . . . . . . . . . . . . . .58  
09 . . . . . . . . . . . “60” . . . . . . . . . . . .60  
10 . . . . . . . . . . . . . . . . . . . . . . . . . . . .62  
11 . . . . . . . . . . . . . . . . . . . . . . . . . . . .64  
12 . . . . . . . . . . . . . . . . . . . . . . . . . . . .66  
13 . . . . . . . . . . . . . . . . . . . . . . . . . . . .69  
14 . . . . . . . . . . . . . . . . . . . . . . . . . . . .71  
15 . . . . . . . . . . . . . . . . . . . . . . . . . . . .74  
16 . . . . . . . . . . . . . . . . . . . . . . . . . . . .77  
17 . . . . . . . . . . . “80” . . . . . . . . . . . .80  
18 . . . . . . . . . . . . . . . . . . . . . . . . . . . .85  
19 . . . . . . . . . . . . . . . . . . . . . . . . . . . .86  
20 . . . . . . . . . . . . . . . . . . . . . . . . . . . .90  
21 . . . . . . . . . . . . . . . . . . . . . . . . . . . .95  
22 . . . . . . . . . . . . . . . . . . . . . . . . . . . 100  
23 . . . . . . . . . . . . . . . . . . . . . . . . . . . 104  
24 . . . . . . . . . . . . . . . . . . . . . . . . . . . 110  
25 . . . . . . . “12 o’clock. . . . . . . 116  
26 . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
27 . . . . . . . . . . . . . . . . . . . . . . . . . . . 131  
28 . . . . . . . . . . . . . . . . . . . . . . . . . . . 141  
29 . . . . . . . . . . . . . . . . . . . . . . . . . . . 151  
30 . . . . . . . . . . . . . . . . . . . . . . . . . . . 165  
31 . . . . . . . . . . . . . . . . . . . . . . . . . . . 180  
32 . . . . . . . . . . . . . . . . . . . . . . . . . . . 200  
33 . . . . . . . . . . . . . . . . . . . . . . . . . . . 224  
34 . . . . . . . . . . “250” . . . . . . . . . . 248  
35 . . . . . . . . . . . . . . . . . . . . . . . . . . . 293  
36 . . . . . . . . . . . . . . . . . . . . . . . . . . . 347  
37 . . . . . . . . . . . . . . . . . . . . . . . . . . . 422  
38 . . . . . . . . . . . . . . . . . . . . . . . . . . . 459  
39 . . . . . . . . . . “500” . . . . . . . . . . 504  
40 . . . . . . . . . . . . . . . . . . . . . . . . . . . 508  
41 . . . . . . . . . . . . . . . . . . . . . . . . . . . 508  
Full-clockwise: 508  
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 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  
test tones (-10 dB, -20 dB, etc.).  
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.  
18 | JL Audio - HD900/5 Owner’s Manual  
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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  
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. If bridged,  
make sure you test the voltage at the correct  
connectors (L+ and R–).  
used to drive the HD900/5). Disconnect  
the HD-RLC Remote Level Control  
temporarily (if one is being used).  
8) Increase the “Input Sens.” control until  
the target voltage is delivered for that  
set of channels. If excessive voltage is  
read with the control at minimum (full  
counterclockwise), switch the “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 any set of channels  
requires attenuation to achieve the desired  
system balance.  
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 the subwoofer channel is being  
driven by a source 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.  
5) 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. Play a  
track with an appropriate sine wave (within the  
frequency range to be amplified by each set of  
Front or rear  
cHannels  
subwooFer  
cHannel  
nom.  
impedance  
stereo  
20.0 V  
20.0 V  
20.0 V  
16.0 V  
12.3 V  
10.6 V  
bridged  
40.0 V  
mono  
44.7 V  
44.7 V  
44.7 V  
38.7 V  
31.6 V  
27.4 V  
8Ω  
6Ω  
32.0 V  
4Ω  
24.6 V  
3Ω  
21.2 V  
not recommended  
not recommended  
2Ω  
1.5Ω  
19  
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aPPendix d: troublesHooting  
“How do i properly set the input sensitivity on my amplifier”  
Please refer to Appendix C (pages 18, 19) to set the input sensitivity  
for maximum, low-distortion output.  
“my amplifier doesnt turn on”  
Check the fuse(s), 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 get a distorted / attenuated 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 speaker lead and  
the vehicle’s chassis 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  
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 a different set of  
cables and/or a different signal source to be sure.  
Reset the amplifier by removing the power plug, then wait ten  
seconds and reconnect the power plug.  
“my amplifiers 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 connector plugs.  
Check the input connectors to ensure that they all are making good  
contact with the input jacks on the amplifier.  
20 | JL Audio - HD900/5 Owner’s Manual  
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“my amplifier shuts off once in a while, usually at higher volumes”  
Check your voltage source and grounding point. The power supply  
of the HD900/5 will operate with charging system voltages  
down to 9V. Shutdown problems at higher volume levels  
can occur when the charging system voltage drops below  
9V. 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 vehicle’s chassis and the  
power wire connecting the alternator to the battery. Many  
vehicles employ small (10 AWG - 6 AWG) wire to ground the  
battery to the vehicle’s chassis 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 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 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 200mV and 8.0-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. Unless you enjoy test tones at high levels,  
it is a good idea to remove the Speaker Connector Plugs  
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 Speaker Connector  
Plugs. The speaker wire connectors are designed to accept up  
to 12 AWG wire. Make sure to strip the wire to allow for a  
sufficient connection with the metal inside each terminal.  
21  
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installation notes:  
use this diagram to document your amplifiers switch and control positions.  
22 | JL Audio - HD900/5 Owner’s Manual  
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23  
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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 from the original date of purchase.  
This warranty is not transferable 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 products 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. Non-  
defective 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.  
Single-Cycle Control™ (U.S. Patent #6,084,450) is used under exclusive license for mobile audio from Power Physics, Inc. - Newport Beach, CA  
HD900/5MAN-CH-050509  
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