JL Audio 450/4V2 User Manual

2  |  JL Audio - 450/4

v2

 Owner’s Manual  

3

Your JL Audio amplifier employs an 

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 back 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, but 
you still need to follow some basic guidelines:
t"NQMJGJFSNPVOUFEWFSUJDBMMZXJUIIFBUTJOLGJOT

pointing up: Optimum

t"NQMJGJFSNPVOUFEIPSJ[POUBMMZ  

right side up: Good

t"NQMJGJFSNPVOUFEIPSJ[POUBMMZ CVUVQTJEF

down: Fair (not recommended if there is 
less than 1 inch (2.5 cm) clearance above the 
amplifier heat sinks)

t"NQMJGJFSNPVOUFEWFSUJDBMMZXJUIIFBUTJOLGJOT

pointing laterally: Fair

t"NQMJGJFSNPVOUFEWFSUJDBMMZXJUIIFBUTJOLGJOT

pointing down: Poor (not recommended)

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.

Your amplifier needs to be installed in a dry,  

well-ventilated environment and in a manner  
which does not interfere with your vehicle’s safety 
equipment (air bags, seat belt systems, ABS brake 
systems, etc.). You should also take the time to 
securely mount the amplifier using appropriate 
hardware so that it does not come loose in the 
event of a collision or a sudden jolt to the vehicle.

 

Stupid Mistakes to Avoid: 
tCheck 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.

t%POPUSVOTZTUFNXJSJOHPVUTJEFPSVOEFSOFBUI

the vehicle. This is an extremely dangerous 
practice which can result in severe damage to 
your vehicle and person.

t1SPUFDUBMMTZTUFNXJSFTGSPNTIBSQNFUBM 

edges and wear by carefully routing them,  
tying them down and using grommets and  
loom where appropriate.

t%POPUNPVOUUIFBNQMJGJFSJOUIFFOHJOF

compartment, under the vehicle, on the roof  
or in any other area that will expose the 
amplifier circuitry to the elements.

We value you as a long-term customer. For 

that reason, we urge you to practice restraint in 
the operation of this product so as not to damage 
your hearing and that of others in your vehicle. 
Studies have shown that continuous exposure to 
high sound pressure levels can lead to permanent 
(irreparable) hearing loss. This and all other 
high-power amplifiers are capable of producing 
such high sound pressure levels when connected 
to a speaker system. Please limit your continuous 
exposure to high volume levels.

While driving, operate your audio system in 

a manner that still allows you to hear necessary 
noises to operate your vehicle safely (horns,  
sirens, etc.).

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.

 

This amplifier is designed for operation in 

vehicles with 12V, negative-ground electrical 
systems. Use of this product in vehicles with 
positive ground and/or voltages other than 12V 
may result in damage to the product and will void 
the warranty.

This product is not certified or approved for 

use in aircraft.

%POPUBUUFNQUUPiCSJEHFwUIFPVUQVUTPGUIJT

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.

 

Left Output

Right Output

HP Filter Freq. (Hz)

Remote

Bass Port

CH 3

(Left)

CH 4

(Right)

CH 1

(Left)

CH 2

(Right)

Freq. Range

Input Voltage

Input Sens.

Input Sens.

Input Mode

2ch | 4ch

Filter Type

LP | BP | HP

x1 | x10

Low | High

Input Voltage

Low | High

High-Pass Filter

Off | 12dB | 24dB

Freq. Range Filter Mode | Slope

x1 | x10

Off | 12dB | 24dB

Infrasonic Filter

Off | 30Hz

Bass EQ

Off | On

Signal From

1 & 2 | 3 & 4 | All

50

60

75

95

130

200

500

50

60

75

95

130

200

500

Filter Freq. (Hz)

v2

Four-Channel System Amplifier

1 & 2

Inputs

Only

Either

feature

sums the

CH 1&2 input

signals to

mono when

activated.

1 & 2

and

3 & 4

Bridged: 150W x 1 (3-8Ω)

Left

Right

Bridged: 300W x 1 (3-8Ω)

Left

Right

Also sets

low-pass

cutoff for

CH 1 & 2

Bandpass

Filter 

(if selected)

CH 1&2

 Filter Slope

Selection / Defeat

(pg. 9)

Infrasonic Filter

On/Off Switch

(pg. 11)

Preamp Output 

Signal Selector

(pg. 10)

Left and Right

Preamp Output Jacks

(pg. 10)

Jack for

Remote Bass 

Control Knob

(pg. 11)

CH 3&4

Input Voltage

Range Selector

(pg. 7)

Selects

2ch / 4ch 

Input Mode

(pg. 7)

CH 3&4 

HP Filter Slope 

Selection / Defeat

(pg. 9)

CH 3&4

Filter Frequency 

Range Selector

(pg. 9)

Selects CH 3&4

High-Pass Cutoff 

Frequency and Low-Pass 

Cutoff for CH 1&2 Bandpass 

Filter

(pg. 10)

CH 3&4

Input Sensitivity 

Control

(pg. 8)

CH 1&2

Left and Right

Input Jacks

(pg. 7)

CH 3&4

Left and Right

Input Jacks

(pg. 7)

Bass EQ 

On/Off Switch

(pg. 11)

CH 1&2

Filter Frequency 

Range Selector

(pg. 9)

CH 1&2

Input Voltage

Range Selector

(pg. 7)

Remote Turn-On 

Connector

(pg. 7)

Chassis Ground 

Connector

(pg. 6)

+12 V Power 

Connector

(pg. 6)

CH 1&2 

Speaker Outputs

(pg. 11)

Selects CH 1&2

  HP or LP Cutoff 

Frequency or HP Cutoff 

of Bandpass Filter

(pg. 8)

CH 3&4

Speaker Outputs

(pg. 11)

CH 1&2 Input

Sensitivity Control

(pg. 8)