JL Audio Car Amplifier G4500 User Manual

owner’s manual  
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.  
Download from Www.Somanuals.com. All Manuals Search And Download.  
ProteCt Your Hearing!  
installation aPPliCations  
Planning Your installation  
We value you as a long-term customer. For  
that reason, we urge you to practice restraint in  
the operation of this product so as not to damage  
your hearing and that of others in your vehicle.  
Studies have shown that continuous exposure to  
high sound pressure levels can lead to permanent  
(irreparable) hearing loss. This and all other  
high-power amplifiers are capable of producing  
such high sound pressure levels when connected  
to a speaker system. Please limit your continuous  
exposure to high volume levels.  
This amplifier is designed for operation in  
vehicles with 12 volt, negative-ground electrical  
systems. Use of this product in vehicles with  
positive ground and/or voltages other than 12V  
may result in damage to the product and will void  
the warranty.  
This product is not certified or approved for  
use in aircraft.  
Do not attempt to “bridge” the outputs of this  
amplifier with the outputs of a second amplifier,  
including an identical one.  
It is important that you take the time to read  
this manual and that you plan out your  
installation carefully. The following are some  
considerations that you must take into account  
when planning your installation.  
Mounting the amplifier upside down is  
strongly discouraged.  
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.  
Cooling efficiency Considerations:  
The outer shell of your JL Audio amplifier  
is designed to remove heat from the amplifier  
circuitry. For optimum cooling performance,  
this outer shell should be exposed to as large a  
volume of air as possible. Enclosing the amplifier  
in a small, poorly ventilated chamber can  
lead to excessive heat build-up and degraded  
performance. If an installation calls for an  
enclosure around the amplifier, we recommend  
that this enclosure be ventilated with the aid  
of a fan. In normal applications, fan-cooling  
is not necessary.  
safety Considerations:  
Your amplifier needs to be installed in a dry,  
well-ventilated environment and in a manner  
which does not interfere with your vehicle’s safety  
equipment (air bags, seat belt systems, ABS brake  
systems, etc.). You should also take the time to  
securely mount the amplifier so that it does not  
come loose in the event of a collision or a sudden  
jolt to the vehicle.  
While driving, operate your audio system in  
a manner that still allows you to hear necessary  
noises to operate your vehicle safely (horns,  
sirens, etc.).  
serial number  
In the event that your amplifier requires  
service or is ever stolen, you will need to have  
a record of the product’s serial number. Please  
take the time to enter that number in the space  
provided below. The serial number can be found  
on the bottom panel of the amplifier and on the  
amplifier packaging.  
stupid mistakes to avoid  
Chassis Ground  
Connector  
(pg. 5)  
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.  
Channels 1 & 2  
Speaker Outputs  
(pg. 8)  
Channels 3 & 4  
Speaker Outputs  
(pg. 8)  
+12 V Power  
Connector  
(pg. 4)  
Remote Turn-On  
Connector  
(pg. 5)  
• 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.  
Serial Number:  
• Protect all system wires from sharp metal  
edges and wear by carefully routing them,  
tying them down and using grommets and  
loom where appropriate.  
Power  
Ch. 1 & 2 Filter  
Ch. 1 & 2 Input  
Sensitivity  
Control  
Ch. 3 & 4  
Filter Mode  
Selection  
(pg. 7)  
Input Voltage  
Selection  
(pg. 6)  
Status  
Indicator  
(pg. 10)  
Frequency  
Selector  
(pg. 7)  
(pg. 6)  
Ch. 1 & 2  
Ch. 3 & 4  
Ch. 3 & 4  
Filter Frequency  
Selector  
• 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.  
Channels 3 & 4  
Preamp Input Jacks  
(pg. 6)  
Protection Status  
Filter Mode  
Selection  
(pg. 7)  
Input Sensitivity  
Control  
Indicator  
(pg. 10)  
(pg. 6)  
(pg. 7)  
Channels 1 & 2  
Preamp Input Jacks  
(pg. 6)  
Left & Right  
Preamp Output  
Jacks  
Ch. 3 & 4  
Bass Boost  
On/Off Switch  
(pg. 8)  
Pre-Out Signal  
Selection Switch  
(pg. 8)  
Jack for  
Ch. 3 & 4  
Input Selection  
Switch  
(pg. 8)  
Remote Bass  
Control Knob  
(pg. 8)  
(pg. 6)  
2
JL AUDIO G4500  
JL AUDIO G4500  
3
Download from Www.Somanuals.com. All Manuals Search And Download.  
ProduCt desCriPtion  
The JL Audio G4500 is a four-channel,  
full-range audio amplifier utilizing patented  
Absolute Symmetry™ Class A/B technology  
for all channels.  
The G4500 can be operated with a wide variety  
of source units and system configurations.  
(90 cm) from the amplifier to the ground  
connection point. In some vehicles, it may be  
necessary to upgrade the battery ground wire.  
(See page 5 for important notice).  
7) Securely mount the amplifier.  
8) Connect the positive and negative power  
wires to the amplifier. A fuse near the  
amplifier is not necessary.  
The G4500’s +12VDCand Ground”  
connections are designed to accept 4 AWG power  
wire. 4 AWG is a minimum power wire size for  
this amplifier.  
If you are installing the G4500 with other  
amplifiers and wish to use a single main power  
wire, use 4 AWG or larger main power wire  
(depending on the overall current demands of all  
the amplifiers in the system). This 4 AWG or  
larger power wire should terminate into a  
distribution block mounted as close to the  
amplifiers as possible and should connect to the  
G4500 with 4 AWG power wire.  
Many vehicles employ small (10 AWG -  
6 AWG) wire to ground the battery to the  
vehicle chassis and to connect the alternator’s  
positive connection to the battery. To prevent  
voltage drops, these wires should be upgraded  
to 4 AWG when installing amplifier systems  
with main fuse ratings above 60A.  
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.  
9) Connect the remote turn-on wire  
to the amplifier.  
Fuse requirements  
It is absolutely vital that the main power wire(s)  
to the amplifier(s) in the system be fused within  
18 inches (45 cm) of the positive battery post  
connection. The fuse value at each power wire  
should be high enough for all of the equipment  
being run from that power wire. If only the  
G4500 is being run from that power wire, we  
recommend a 50A fuse be used. AFS (mini blade  
fuse), AGU (big glass fuse) or MaxiFuse™ (big  
plastic-body fuse) types are recommended.  
No fuse is required or recommended directly  
before the amplifier power connection. If one is  
desired, we recommend the use of a 50A fuse.  
10) Connect the input cables to the amplifier.  
11) Connect the speaker cables to the amplifier.  
12) Carefully review the amplifier’s control  
settings to make sure that they are set  
according to the needs of the system.  
13) Install the power wire fuse (50A for a  
single G4500) and reconnect the negative  
battery post terminal.  
14) Turn on the source unit at a low level  
to double-check that the amplifier is  
configured correctly. Resist the temptation  
to crank it up until you have verified the  
control settings.  
15) Make necessary adjustments to the input  
sensitivity controls to obtain the right  
overall output and the desired balance  
in the system. See Appendix A (page 14)  
for the recommended input sensitivity  
setting method.  
Note: Smaller AWG numbers mean bigger wire  
and vice-versa (1/0 AWG is the largest, 2 AWG is  
smaller, then 4 AWG, then 8 AWG, etc.).  
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 (minimum 8 AWG) from the  
battery location to the amplifier mounting  
location, taking care to route it in such a  
way that it will not be damaged and will not  
interfere with vehicle operation. Use 4 AWG  
or larger power wire and a power distribution  
block if additional amplifiers are being  
installed with the G4500.  
3) Connect power wire to the positive battery  
post. Fuse the wire with an appropriate fuse  
block (and connectors) within 18 inches (45  
cm) wire length of the positive battery post.  
This fuse is essential to protect the vehicle.  
Do not install the fuse until the power wire  
has been securely connected to the amplifier.  
4) Run signal cables and remote turn-on wire  
from the source unit to the final amplifier  
mounting location.  
5) Run speaker cables from the speaker systems  
to the amplifier mounting location.  
6) Find a good, solid metal grounding point  
close to the amplifier and connect the  
negative power wire to it using appropriate  
hardware (use of the JL Audio ECS master  
ground lug, XB-MGLU is recommended).  
Use the same size power wire as the wire  
connected to the “+12VDC” connection  
(minimum 8 AWG), no longer than 36 inches  
To connect the power wires to the amplifier,  
first back out the set screw on the top of the  
terminal block, using the supplied 2.5 mm hex  
wrench. Strip 1/2 inch (12 mm) of insulation from  
the end of each wire and insert the bare wire into  
the terminal block, seating it firmly so that no  
bare wire is exposed. While holding the wire in  
place, tighten the set screw firmly, taking care not  
to strip the head of the screw and making sure  
that the wire (not the insulation) is firmly gripped  
by the set screw.  
The ground connection should be made using  
the same gauge wire as the power connection  
and should be kept as short as possible, while  
accessing a solid piece of sheet metal in the  
vehicle. The surface of the sheet metal should  
be sanded at the contact point to create a clean,  
metal-to-metal connection between the chassis  
and the termination of the ground wire. For  
optimal grounding, we recommend the use of a  
JL Audio ECS master ground lug (XB-MGLU).  
Alternatively, a sheet metal screw or bolt can be  
used with a star washer.  
turn-on lead  
The G4500 uses a conventional +12V remote  
turn-on lead, typically controlled by the source  
unit’s remote turn-on output. The amplifier will  
turn on when +12V is present at its Remote”  
input and turn off when +12V is switched off. If  
a source unit does not have a dedicated remote  
turn-on output, the amplifier’s turn-on lead can  
be connected to +12V via a switch that derives  
power from an ignition-switched circuit.  
The G4500’s Remoteturn-on connector is  
designed to accept 18 AWG – 12 AWG wire. To  
connect the remote turn-on wire to the amplifier,  
first back out the set screw on the top of the  
terminal block, using the supplied 2.5mm hex  
wrench. Strip 1/2 inch (12mm) of wire and insert  
the bare wire into the terminal block, seating it  
firmly so that no bare wire is exposed. While  
holding the wire in the terminal, tighten the set  
screw firmly, taking care not to strip the head of  
the screw and making sure that the wire (not the  
insulation) is firmly gripped by the set screw.  
16) Enjoy the fruits of your labor with your  
favorite music.  
Power ConneCtions  
Before installing the amplifier, disconnect the  
negative (ground) wire from the vehicle’s battery.  
This will prevent accidental damage to the system,  
the vehicle and your body during installation.  
Any wires run through metal barriers (such  
as firewalls), must be protected with a high  
quality rubber grommet to prevent damage to the  
insulation of the wire. Failure to do so may result  
in a dangerous short circuit.  
4
JL AUDIO G4500  
JL AUDIO G4500  
5
Download from Www.Somanuals.com. All Manuals Search And Download.  
inPut seCtion  
The G4500’s input section allows you to send  
signals to the amplifier section through the use of  
either two or four differential-balanced inputs.  
Input connections are via traditional  
RCA-type jacks.  
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.  
No line output converter is needed in most cases.  
Do not increase any “Input Sens.” setting for  
any channel(s) of any amplifier in the system  
beyond the maximum level established during  
the procedure outlined in Appendix A (page  
14). Doing so will result in audible distortion  
and possible speaker damage.  
1) “Filter Mode” Control: The G4500 employs a  
12dB per octave filter for each pair of channels  
(one filter for channels 1&2 and another filter  
for channels 3&4). Each of these filters can  
be configured independently into one of two  
filter types or defeated completely by way of the  
three-position Filter Modeswitches:  
“Off”: Defeats the filter completely, allowing  
the full range of frequencies present at the  
inputs to feed the amplifier. This is useful  
for systems utilizing outboard crossovers or  
requiring full-range reproduction from one or  
both of the G4500’s channel pairs.  
“LP” (Low-Pass): Configures the filter to  
attenuate frequencies above the selected filter  
frequency at a rate of 12dB per octave. This is  
useful for connection of subwoofer(s) to one  
or both of the G4500’s channel pairs in a  
bi-amplified system.  
The output of the amplifier will decrease for  
a given input voltage when the “Input Range”  
switch is placed in the “High” position.  
Conversely, the output will be higher with the  
switch in the “Low” position. While this may  
sound counter-intuitive, it is consistent with the  
descriptions in this section.  
Filter Controls  
Most speakers are not designed to reproduce  
the full range of frequencies audible by the  
human ear. For this reason, most speaker  
systems are comprised of multiple speakers, each  
dedicated to reproducing a specific frequency  
range. Filters are used to select which frequency  
range is sent to each section of a speaker system.  
The division of frequency ranges to different  
speakers can be done with passive filters (coils  
and/or capacitors between the amplifier outputs  
and the speakers), which are acceptable and  
commonly used for filtering between mid-  
range speakers and tweeters. Filtering between  
subwoofer systems and satellite speaker systems  
is best done with active filters, which cut off  
frequency content at the input to the amplifier.  
Active filters are more stable than passive filters  
and do not introduce extraneous resistance,  
which can degrade subwoofer performance.  
The active filter built into each channel section  
of the G4500 can be used to eliminate potentially  
harmful and/or undesired frequencies from  
making their way through the amplifier sections  
to the speaker(s). This serves to improve tonal  
balance and to avoid distortion and possible  
speaker failure. Correct use of these filters can  
substantially increase the longevity and fidelity  
of your audio system.  
inPut sensitiVitY Controls  
Once the appropriate “Input Voltage” range  
has been selected, the controls labeled “Input  
Sens.” located in each “Channel Controls”  
section 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 a given input  
voltage). Rotating the control counter-clockwise  
will result in lower sensitivity (quieter for a given  
input voltage.)  
If you wish to send four discrete channels into  
the G4500, simply use all four inputs (channels  
1 & 2 and channels 3 & 4) and set the “CH 3&4  
Input From” switch to “Discrete”.  
If you wish to feed all four channels by using  
only two channels of input, set the “CH 3&4  
Input From” switch to “1&2” and use only the  
inputs to channels 1 & 2.  
“HP” (High-Pass): Configures the filter to  
attenuate frequencies below the selected filter  
frequency at a rate of 12dB per octave. This is  
useful for connection of component speakers to  
one or both of the G4500’s channel pairs in a  
bi-amplified system.  
input Voltage range:  
2) “Filter Freq. (Hz)” 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  
chart in Appendix B (page 15).  
A wide range of signal input voltages can be  
accommodated by the G4500’s input sections  
(200mV – 8V). This wide range is split up into  
two sub-ranges, accessible via a switch located to  
the left of the Input Connectors. Be aware that the  
position of this switch will dictate the sensitivity  
range for all four input channels.  
The “Low” position on the “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. If you are using an aftermarket  
source unit or an OEM interface processor with  
conventional preamp-level outputs, this is most  
likely the position that you will use.  
Tuning Hint: If you are using the G4500 to drive  
a subwoofer system (LPmode), a component  
satellite speaker system (HPmode) or both,  
80 Hz is a good baseline Filter Freq. (Hz)”  
setting. After properly adjusting the Input  
Sens., as outlined in Appendix A (page 14), you  
can fine tune the Filter Freq. (Hz)control to  
achieve the desired system frequency response.  
To properly set the amplifier for maximum  
clean output, please refer to Appendix A (page  
14) in this manual. After using this procedure,  
you can then adjust any or all “Input Sens.”  
levels downward if this is required to achieve the  
desired system balance.  
The High” position on the “Input Voltage”  
switch selects an input sensitivity range between  
800mV and 8V. This is useful for certain high-  
output preamp level signals as well as speaker-  
level output from source units and  
small amplifiers.  
6
JL AUDIO G4500  
JL AUDIO G4500  
7
Download from Www.Somanuals.com. All Manuals Search And Download.  
bass boost Controls  
sPeaker outPuts  
2) “Sum”: When the G4500 is being used to drive  
front and rear speaker systems, this preamp  
output mode will deliver a summed front/rear  
stereo signal to a subwoofer amplifier, while  
permitting fading of the front and rear speaker  
systems from the source unit. This method  
prevents a loss of signal to the subwoofer  
amplifier when the system is faded to the front  
or the rear by the head unit.  
The G4500’s speaker outputs are designed to  
accept 16 AWG - 8 AWG wire.  
Each pair of the G4500’s channels are  
designed to deliver power into speaker loads equal  
to or greater than 2 ohms per channel when using  
a “stereo” configuration and speaker loads equal  
to or greater than 4 ohms per bridged pair of  
channels when using a “bridged” configuration.  
When a pair of channels are bridged, they  
will deliver 250W x 1 into a 4 ohm load or  
160W x 1 into an 8 ohm load. Operating a  
pair of bridged channels into a load lower  
than 4 ohms is not recommended.  
Because a bridged pair of channels requires that  
both channels receive input, you need to  
connect both left and right inputs to the source  
unit. Connection of only one input will result in  
reduced power output, increased distortion and  
can cause the amplifier to overheat.  
Note: Any signal delay between the front and rear  
channels can result in a cancellation of signals  
within certain frequency ranges when using the  
Sumposition. If you experience a loss of bass  
output in the Sumposition, compared to the  
1&2” position, you are likely dealing with a  
delayed signal in either the front or rear outputs  
of the source unit. If the front to rear delay is  
desirable for other reasons or if it cannot be  
defeated at the source unit, we recommend that  
you use the “1&2position.  
1) “CH 3&4 Bass Boost”: Found in the Channel  
3 & 4 Controlssection, this switch allows the  
user to activate a 6 dB boost centered at 48 Hz  
for channels 3 & 4. When the CH 3&4 Bass  
Boostis activated, the inputs to CH 3 (Left)”  
and CH 4 (Right)are summed to create a  
mono signal. The Filter Modeswitch in the  
Channel 3 & 4section must be in the LP”  
position for the bass boost to be functional.  
Do not do this!  
When a pair of the G4500’s channels are  
operating in bridged mode, the output will be in  
mono (only one channel). This mono channel  
can contain right channel only information,  
left channel only information or the sum of  
the information from both the right and left  
channels. In order to achieve one of these options,  
configure the inputs to that pair of channels in  
one of these two ways:  
2) Remote Bass Port”: This port allows you to  
connect an optional remote boost knob (sold  
separately as JL Audio Model RBC-1) that can  
be mounted in the front of the vehicle. With  
the RBC-1 connected, the boost is no longer  
limited to 0 or +6 dB, allowing a variable  
range of 0 to +12 dB of boost to be selected.  
Note: In either mode, the preamp output signal  
is not affected by the “CH 3&4 Bass Boost”  
processing selected for the amplifier or by any  
crossover filter selected (if the input signal is full-  
range, the preamp output will be full-range).  
Speaker loads below 2 ohms nominal per  
channel are not recommended and may cause  
the amplifier to initiate a protection mode  
which reduces power output.  
1) Left Channel Only or Right Channel Only  
Information: If you wish to send a left-only  
or right-only signal to a pair of the G4500’s  
channels, use a “Y-Adaptor” to split the single  
channel signal into both left and right RCA  
inputs. This option is useful when using a pair  
of the G4500’s channels to drive left channel  
speakers only and the other pair of the G4500’s  
channels to drive right channel speakers only.  
bridging Considerations  
Note: The signal level of the “Preamp Outputis  
line-level (low voltage), regardless of the position  
selected in the G4500’s “Input Voltage” switch.  
An additional amplifier connected to these  
preamp outputs should have its input voltage  
switch set to the Lowposition.  
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 G4500 has been designed for  
bridging of its channel pairs without the need for  
input inversion adaptors.  
Pre-outs  
The G4500 incorporates a pass-through  
preamp output section, so that additional  
amplifiers can be easily added to the system. This  
pass-through pre-amp output can be configured  
two different ways using the switch labeled  
Pre-Outs Input From.  
2) Left + Right Channel Information:  
When bridged and fed by a stereo input, a pair  
of the G4500’s channels will automatically  
combine the left and right channels into a  
summed mono (left + right) channel. This  
option is useful when using a pair of the  
G4500’s channels to drive a subwoofer system  
or a summed mono center channel.  
To bridge a pair of channels, use the  
1) “1&2”: The preamp output delivers the same  
signal that is connected to the CH 1&2 Inputs.  
This mode is useful for feeding a subwoofer  
amplifier when the G4500 is being used to  
drive front and rear speaker systems. In this  
mode, the preamp output signal will depend  
only on the input signal level of CH 1&2,  
allowing Channels 3&4 to be faded without  
affecting the subwoofer level. If CH 1&2 is  
faded in this mode, the signal level of the  
preamp output will change accordingly.  
Left +” and “Right –speaker connectors only  
(the “Left –and Right +remain unused).  
When bridged, each channel will deliver  
optimum power into a 4 ohm load.  
8
JL AUDIO G4500  
JL AUDIO G4500  
9
Download from Www.Somanuals.com. All Manuals Search And Download.  
amPliFier status indiCator ligHts &  
ProteCtion CirCuitrY  
There are two status indicator lights on the  
input / control end of the amplifier.  
sYstem ConFigurations  
low-Voltage protection:  
The G4500 is a flexible amplifier, well-suited  
for a multitude of system configurations. In  
this section, the most likely configurations are  
explained in detail.  
Once you have selected your desired  
configuration, you can use the amplifier panel  
drawing on pages 18 & 19 to mark the required  
switch positions for easy reference.  
B ) Fade Subwoofer Level vs. HF Level  
R e q u i r e d : a source unit or processor with two  
pairs of stereo outputs.  
Input Connections: the first stereo pair source  
unit outputs is connected to the “CH 1 (Left)”  
and “CH 2 (Right)” inputs of the G4500. The  
second stereo pair of source unit outputs is  
connected to the “CH 3 (Left)” and “CH 4  
(Right)” inputs (select “Discrete” on the “CH  
3&4 Input From” switch).  
R e s u l t : in this mode, the user has the ability to  
fade or control the level of the LF channels  
relative to the HF channels via the source  
unit’s fader control without exceeding the  
maximum clean output level set by each  
amplifier section’s “Input Sens.” controls.  
If the car’s supply voltage drops below 10  
volts, the entire amplifier will shut itself off to  
protect its internal circuitry. The green “Power”  
indicator will turn off when this occurs. The  
amplifier will turn back on when voltage climbs  
back above 10 volts. This may happen in a rapid  
cycle when bass-heavy program material causes  
a weak charging system to dip below 10 volts  
momentarily. If this is happening in your system,  
turn your audio system off and have your power  
wiring, ground connections and charging  
system inspected.  
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.  
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.  
1) Power(Green): lights to indicate that the  
amplifier is turned on and operating normally.  
C) Subwoofer Level Control Only:  
2) Protect(Red): Indicates that the amplifier  
protection circuitry has been activated to  
prevent product failure due to a short-circuit  
or a dangerously low impedance connected  
to the amplifier output(s). Connecting the  
speaker outputs to an impedance lower than  
2 ohms stereo (4 ohms bridged) will cause  
this protection mode to activate. When this  
protection mode is activated, the amplifier will  
reduce it maximum power output to protect its  
circuitry, which will manifest itself as increased  
distortion. When the problem is corrected, the  
amplifier will return to normal operation.  
R e q u i r e d : a source unit or processor with  
one pair of stereo outputs and dedicated  
subwoofer outputs.  
Input Connections: the main stereo pair of  
source unit outputs is connected to the “CH  
1 (Left)” and “CH 2 (Right)” inputs of the  
G4500. The source unit’s dedicated subwoofer  
output is connected to the “CH 3 (Left)” and  
CH 4 (Right)” inputs (select “Discrete” on  
the “CH 3&4 Input From” switch).  
The G4500 can be configured to drive a  
bi-amplified system by itself or with a separate  
subwoofer amplifier.  
bi-amplified system with one g4500  
In this configuration, channels 3&4 of the  
G4500 will drive subwoofers (stereo or bridged)  
with low-pass filtering. Channels 1&2 will  
drive component speakers in stereo with  
high-pass filtering.  
R e s u l t : in this mode, the user has the ability to  
control the absolute level of the LF channels  
relative to the HF channels.  
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.  
Input connection options for a bi-amplified system  
with one G4500 are as follows:  
advanced rollback thermal protection  
Unlike conventional thermal protection  
systems, which shut down an amplifier when it  
overheats, this system protects the amplifier by  
gradually reducing power output if the amplifier’s  
safe operating temperature is exceeded. The  
amplifier will continue to operate and return  
to normal power output once its temperature  
returns to a normal range.  
Set the “Input Sens.” in the “Channel 3 & 4  
Controls” section with the source unit’s  
subwoofer level control set at 3/4 of full output.  
See Appendix A (page 14) for details.  
Jl audio technical support:  
(954) 443-1100  
9:00 AM – 5:30 PM (Eastern Time Zone)  
Monday - Friday  
A) No User Adjustability:  
R e q u i r e d : a basic source unit or processor  
with one pair of stereo outputs.  
Input Connections: a single pair of stereo source  
unit outputs connected to the “CH 1 (Left)”  
and“CH 2 (Right)” inputs of the G4500 (select  
1&2” on the “CH 3&4 Input Fromswitch.  
R e s u l t : the relative level of the LF and HF  
channels will be determined by the G4500’s  
Input Sens.” settings and will not be user  
adjustable from the front of the vehicle.  
Crossover Setup for Bi-Amplified System  
with one G4500:  
Once the input sections have been configured  
appropriately, go to the “Channel 3 & 4  
Controls”. Select “LP” (low-pass) on the “Filter  
Mode” switch and an appropriate “Filter Freq.”  
(80 Hz is a good starting point).  
10  
JL AUDIO G4500  
JL AUDIO G4500  
11  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Next, turn your attention to the Channel 1 &  
2 Controlsand select HP(high-pass) on the  
Filter Modeswitch and an appropriate Filter  
Freq.(again, 80 Hz is a good starting point).  
After proper adjustment of the “Input Sens.”  
controls for both channel pairs using the method  
shown in Appendix A (page 14), you can fine  
tune filter frequencies and attenuate either pair  
of channels to achieve proper balance. For precise  
filter frequency information refer to Appendix B  
(page 15).  
B) Fade Subwoofer Level vs. HF Level:  
R e q u i r e d : a source unit or processor with front  
and rear pairs of stereo outputs.  
Input Connections: one stereo pair of source unit  
outputs is connected to the “CH 1 (Left)” and  
CH 2 (Right)” inputs of the G4500 (select  
1&2” on the “CH 3&4 Input From” switch).  
The second stereo pair of source unit outputs  
is connected to the subwoofer amplifier  
inputs.  
R e s u l t : with this option, the user has the ability  
to fade the level of the subwoofer amplifier’s  
input relative to the HF channels, but  
cannot control front-to-rear fading of the  
HF channels. The relative level of the front and  
rear HF channels will be fixed by the G4500’s  
Input Sens.” settings and will not be user  
adjustable from the front of the vehicle.  
D) Front to Rear HF Fading and Subwoofer  
Level Control:  
R e q u i r e d : a source unit or processor with  
front and rear pairs of stereo outputs plus a  
dedicated subwoofer output.  
Set the subwoofer amplifier’s “Input Sens.”  
with the source unit’s subwoofer level control  
set at 3/4 of full output.  
Crossover Setup for Bi-Amplified System with  
one G4500 and a separate subwoofer amplifier:  
Input Connections: one stereo pair of source unit  
outputs is connected to the CH 1 (Left)and  
CH 2 (Right)inputs of the G4500.  
The second stereo pair of source unit  
outputs is connected to the CH 3 (Left)”  
and CH 4 (Right)inputs of the G4500  
(select Discreteon the CH 3&4 Input  
Fromswitch). The source unit’s dedicated  
subwoofer output is connected to the  
subwoofer amplifier inputs.  
R e s u l t : with this option, the user has the ability to  
fade the front and rear HF channels relative to  
each other and also has the ability to control  
the absolute level of the subwoofer channel  
relative to the HF channels.  
Once the input and preamp output sections  
have been configured appropriately, go to the  
Channel 1 & 2 Controlsand Channel 3 &  
4 ControlsYou will set both control sections  
identically to start:  
Select HP(high-pass) on the Filter Mode”  
switch and an appropriate Filter Freq.(80 Hz is  
a good starting point). Make these adjustments to  
both control sections.  
After proper adjustment of the G4500’s  
Input Sens.controls, and the subwoofer  
amplifier’s input sensitivity controls, you can fine  
tune filter frequencies and attenuate either pair  
of channels to achieve proper balance. For proper  
adjustment of the Input Sens.controls of the  
G4500 use the method shown in Appendix A  
(page 14). For precise filter frequency information  
for the G4500 refer to Appendix B (page 15).  
Refer to the subwoofer owner’s manual for  
proper adjustments.  
bi-amplified system with one g4500 in  
four-channel mode and a separate  
subwoofer amplifier  
This configuration requires that the separate  
subwoofer amplifier has a built-in low-pass filter.  
All JL Audio amplifiers have this feature.  
In this configuration, channels 1&2 of the G4500  
will drive front component speakerswith high-  
pass filtering. Channels 3&4 will drive  
rear component speakers in stereo, also with  
high-pass filtering. The separate amplifier  
will drive the subwoofer system with low-pass  
filtering (80 Hz is a good starting point).  
C) Subwoofer Level Control Only:  
Required: a source unit or processor with left,  
right and dedicated subwoofer outputs.  
Input Connections: The main stereo pair  
of source unit outputs is connected to the  
CH 1 (Left)and CH 2 (Right)inputs  
of the G4500 (select 1&2on the CH 3&4  
Input Fromswitch). The source unit’s  
dedicated subwoofer output is connected to  
the subwoofer amplifier inputs.  
Input connection options for a bi-amplified  
system with one G4500 and a separate subwoofer  
amplifier are as follows:  
R e s u l t : with this option, the user has the ability  
to control the absolute level of the subwoofer  
channel relative to the HF channels, but  
cannot fade the front and rear HF channels  
relative to each other.  
A) No User Adjustability:  
R e q u i r e d : a basic source unit or processor with  
one pair of stereo outputs.  
Input Connections: a single pair of stereo source  
unit outputs is connected to the “CH 1 (Left)”  
and “CH 2 (Right)” inputs of the G4500 (select  
1&2” on the “CH 3&4 Input From” switch).  
Connect the subwoofer amplifier inputs to  
the preamp outputs of the G4500 (Select  
1&2” on the “Pre-Outs Input From” switch.  
Alternatively, the G4500 can receive its input  
from the subwoofer amplifier’s preamp output  
set to “full-range” mode (if applicable).  
R e s u l t : the relative level of the LF and front  
and rear HF channels will be fixed by the  
G4500’s “Input Sens.” settings (as well as the  
subwoofer amplifier’s settings) and will not be  
user adjustable from the front of the vehicle.  
Set the subwoofer amplifier’s “Input Sens.”  
with the source unit’s subwoofer level control  
set at 3/4 of full output.  
12  
JL AUDIO G4500  
JL AUDIO G4500  
13  
Download from Www.Somanuals.com. All Manuals Search And Download.  
aPPendix a:  
aPPendix b:  
aPPendix C:  
input sensitivity level setting  
8) Increase the Input Sens.control until the  
target voltage is observed with the voltmeter.  
9) Once you have adjusted the G4500 to its  
maximum low-distortion output level,  
reconnect the speaker(s). The Input Sens.”  
controls can now be adjusted downward if the  
amplifier requires attenuation to achieve the  
desired system balance.  
Precise Frequency selection Chart  
g4500 specifications  
Following the directions below will allow the  
installer to adjust the input sensitivity of each  
amplifier channel pair simply and easily in just a  
few minutes using equipment which is commonly  
available in installation bays.  
“Filter Freq” amP Filter  
general specifications:  
Recommended Fuse Value: 50A  
detent  
number  
Panel  
marking  
actual  
Freq.  
Recommended Fuse Type: AFS, AGU or MaxiFuse™  
Full counter-clockwise: 53  
01 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53  
02 . . . . . . . . . . . “50” . . . . . . . . . . . .53  
03 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53  
04 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54  
05 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54  
06 . . . . . . . . . . . . . . . . . . . . . . . . . . . .55  
07 . . . . . . . . . . . . . . . . . . . . . . . . . . . .55  
08 . . . . . . . . . . . “55” . . . . . . . . . . . .56  
09 . . . . . . . . . . . . . . . . . . . . . . . . . . . .56  
10 . . . . . . . . . . . . . . . . . . . . . . . . . . . .57  
11 . . . . . . . . . . . . . . . . . . . . . . . . . . . .58  
12 . . . . . . . . . . . . . . . . . . . . . . . . . . . .59  
13 . . . . . . . . . . . . . . . . . . . . . . . . . . . .62  
14 . . . . . . . . . . . “60” . . . . . . . . . . . .65  
15 . . . . . . . . . . . . . . . . . . . . . . . . . . . .65  
16 . . . . . . . . . . . . . . . . . . . . . . . . . . . .66  
17 . . . . . . . . . . . . . . . . . . . . . . . . . . . .70  
18 . . . . . . . . . . . . . . . . . . . . . . . . . . . .73  
19 . . . . . . . . . . . . . . . . . . . . . . . . . . . .77  
20 . . . . . . . . . . . “80” . . . . . . . . . . . .81  
21 . . . . . . . . . . . . . . . . . . . . . . . . . . . .84  
22 . . . . . . . . . . . . . . . . . . . . . . . . . . . .88  
23 . . . . . . . . . . . . . . . . . . . . . . . . . . . .94  
24 . . . . . . . . . . . . . . . . . . . . . . . . . . . 101  
25 . . . . . . . . . . . . . . . . . . . . . . . . . . . 104  
26 . . . . . . . . . . “120” . . . . . . . . . . 115  
27 . . . . . . . . . . . . . . . . . . . . . . . . . . . 118  
28 . . . . . . . . . . . . . . . . . . . . . . . . . . . 128  
29 . . . . . . . . . . . . . . . . . . . . . . . . . . . 137  
30 . . . . . . . . . . . . . . . . . . . . . . . . . . . 146  
31 . . . . . . . . . . . . . . . . . . . . . . . . . . . 164  
32 . . . . . . . . . . “150” . . . . . . . . . . 177  
33 . . . . . . . . . . . . . . . . . . . . . . . . . . . 193  
34 . . . . . . . . . . . . . . . . . . . . . . . . . . . 197  
35 . . . . . . . . . . . . . . . . . . . . . . . . . . . 209  
36 . . . . . . . . . . . . . . . . . . . . . . . . . . . 213  
37 . . . . . . . . . . . . . . . . . . . . . . . . . . . 216  
38 . . . . . . . . . . “200” . . . . . . . . . . 218  
39 . . . . . . . . . . . . . . . . . . . . . . . . . . . 225  
Full-clockwise: 225  
input sections:  
No. of Inputs: Two Stereo Pairs  
necessary equipment  
• Digital AC Voltmeter  
Input Type: Differential-balanced with RCA jack inputs  
Input Range: Switchable from 200mV - 2V RMS to  
800mV - 8V RMS  
• CD with a sine-wave test tone recorded at  
0 dB reference level in the frequency range  
to be amplified for that set of channels  
(50 Hz for subwoofer channels, 1 kHz for a  
midrange application). Do not use attenuated  
test tones (-10 dB, -20 dB, etc.).  
Do not increase any Input Sens.setting for  
any amplifier channel or channel pair in the  
system beyond the maximum level established  
during this procedure. Doing so will result in  
audible distortion and possible speaker damage.  
amplifier section:  
Amplifier Topology: Class A/B with patented Absolute  
Symmetry™ dual N-Channel MOSFET output design  
Power Supply: Unregulated MOSFET switching type  
Rated Power at 14.4V with less than  
1% THD+Noise (20Hz - 20 kHz)  
the nine-step Procedure  
1) Disconnect the speaker(s) from the  
amplifier’s speaker output connectors.  
2) Turn off all processing (bass/treble, loudness,  
EQ, etc.) on the source unit, processors (if  
used) and amplifier. Set fader control to center  
position and subwoofer level control to 3/4 of  
maximum (if used to feed the G4500).  
3) Switch the Input Voltageswitch to Low”  
and turn the Input Sens.control all the  
way down.  
4) Set the source unit volume to 3/4 of full  
volume. This will allow for reasonable gain  
overlap with moderate clipping at full volume.  
5) Using the chart on this page, determine the target  
voltage for input sensitivity adjustment according  
to the nominal impedance of the speaker system  
connected to the amplifier outputs.  
6) Verify that you have disconnected the speakers  
before proceeding. Play a track with an  
appropriate sine wave (within the frequency  
range to be amplified by the G4500) at 3/4  
source unit volume.  
7) Connect the AC voltmeter to the speaker output  
connectors of the amplifier. If the channel  
pair is operating in stereo, it is only necessary  
to measure one channel. If bridged, make sure  
you test the voltage at the correct connectors  
(L+ and R–).  
It will be necessary to re-adjust the  
Input Sens.for the affected channels if any  
equalizer boost is activated after setting the  
Input Sens.with this procedure. This applies  
to any EQ boost circuit, including source unit  
tone controls or EQ circuits. EQ cuts will not  
require re-adjustment.  
Stereo, all channels driven:  
80W RMS x 4 @ 4 ohms, 125W RMS x 4 @ 2 ohms  
Bridged, all channels driven:  
160W RMS x 2 @ 8 ohms, 250W RMS x 2 @ 4 ohms  
Rated Power @ 12.5V with less than  
1% THD + Noise (20Hz - 20 kHz)  
Stereo, all channels driven:  
60W RMS x 4 @ 4 ohms, 90W RMS x 4 @ 2 ohms  
Rated Power Bridged, all channels driven:  
120W RMS x 2 @ 8 ohms, 180W RMS x 2 @ 4 ohms  
Signal to Noise Ratio: >104 dB referred to rated power  
(A-weighted, 20 Hz-20 kHz noise bandwidth)  
Frequency Response: 10 Hz - 25 kHz (+0, -1dB)  
Damping Factor: >200 @ 4 ohms per ch./50 Hz,  
>100 @ 2 ohms per ch. /50 Hz  
nom.  
target aC Voltage  
impedance  
stereo  
bridged  
26.8 V  
17.8 V  
17.8 V  
17.8 V  
17.3 V  
15.8 V  
8Ω  
6Ω  
4Ω  
3Ω  
2Ω  
25.6 V  
24.6 V  
not recommended  
not recommended  
Slew Rate: 22V/µs  
amplifier Filter:  
Filter Type: State-variable, 12dB/octave Butterworth  
with continuously variable cutoff frequency selection  
from 50-200 Hz.  
Configurable as Low-Pass or High-Pass. Defeatable.  
Preamp output:  
Pass-through type, buffered.  
Switch-selectable to pass signal from CH 1&2 inputs  
only or from all four inputs (summed).  
dimensions(lxwxH):  
13.8" x 9.25" x 2.50" (350mm x 235mm x 63.5mm)  
Due to ongoing product development, all specifications are subject to  
change without notice.  
14  
JL AUDIO G4500  
JL AUDIO G4500  
15  
Download from Www.Somanuals.com. All Manuals Search And Download.  
aPPendix d: troublesHooting  
“How do i properly set the input sensitivity on my amplifier”  
“my amplifier shuts off once in a while, usually at higher volumes”  
Check your voltage source and grounding point. The power supply  
Please refer to Appendix A (page 14) to set the input sensitivity for  
maximum, low-distortion output.  
of the G4500 will operate with charging system voltages  
down to 10V. Shutdown problems at higher volume levels  
can occur when the charging system voltage drops below  
10V. These dips can be of very short duration making them  
extremely difficult to detect with a common DC voltmeter.  
To ensure proper voltage, inspect all wiring and termination  
points. It may also be necessary to upgrade the ground  
wire connecting the battery to the 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 doesnt turn on”  
Check the fuse, not just visually, but with a continuity meter. It is  
possible for a fuse to have poor internal connections that  
cannot be found by visual inspection. It is best to take the  
fuse out of the holder for testing. If no problem is found with  
the fuse, inspect the fuse-holder.  
Check the integrity of the connections made to each of the  
+12VDC”, “Ground”, and Remote” terminals. Ensure  
that no wire insulation is pinched by the terminal set screw  
and that each connection is tight.  
Check to make sure there is +12V at the “Remote” connection of the  
amplifier. In some cases, the turn-on lead from the source unit  
is insufficient to turn on multiple devices and the use of a relay  
is required. To test for this problem, jump the +12VDCwire  
to the Remoteterminal to see if the amplifier turns on. If this  
does not work, proceed to the next step.  
“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 0.2 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 wires from the amplifier  
while doing this. Turn the volume up approximately half  
way. 5V or more should be measured at the speaker outputs.  
This output level can vary greatly between amplifiers but it  
should not be in the millivolt range with the source unit at  
half volume. If you are reading sufficient voltage, check your  
speaker connections as explained below.  
“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  
Protectlight will illuminate in this situation. It may be  
helpful to disconnect the speaker wires from the amplifier  
and use a different set of wires connected to a test speaker.  
Check the nominal load impedance to verify that each channel  
of the amplifier is driving a load equal to or greater than  
2 ohms in stereo mode (4 ohms bridged).  
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.  
“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 terminal block.  
Check the input connectors to ensure that they all are making good  
contact with the input jacks on the amplifier.  
Check to ensure that the speaker wires are making a good  
connection with the metal inside the terminal block. The  
speaker wire connectors are designed to accept up to 8 AWG  
wire. Make sure to strip the wire to allow for a sufficient  
connection with the metal inside the terminal block.  
16  
JL AUDIO G4500  
JL AUDIO G4500  
17  
Download from Www.Somanuals.com. All Manuals Search And Download.  
installation notes:  
Use this diagram to document your amplifier’s switch and control positions.  
18  
JL AUDIO G4500  
JL AUDIO G4500  
19  
Download from Www.Somanuals.com. All Manuals Search And Download.  

Invacare Mobility Aid 00 309 User Manual
Jacuzzi Hot Tub j315 User Manual
John Deere Impact Driver AT 3201 J User Manual
JVC Headphones HA NCX78 J C User Manual
JVC Stereo System 0207WMKMDCJEM User Manual
Kaidan Camcorder Accessories KiWi+ User Manual
KitchenAid Cooktop 3188086 User Manual
Kompernass Laminator ULG 350 A1 User Manual
Kompernass Power Hammer PFBS 6 V User Manual
Kramer Electronics Electronic Accessory PIP 200 User Manual