2
| JL Audio - RD400/4 Owner’s Manual
PROTECT YOUR HEARING!
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.).
SERIAL NUMBER
In the event that your amplifier requires
service or is ever stolen, you will need to have
a record of the product’s serial number. Please
take the time to enter that number in the space
provided below. The serial number can be found
on the bottom panel of the amplifier and on the
amplifier packaging.
Serial Number:
INSTALLATION APPLICATIONS
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.
WHAT’S INCLUDED
(1) RD400/4 amplifier
(1) Control panel cover (removable)
(1) Round logo badge
(1) 2.5 mm hex wrench
(1) User manual
Left
or
Mono
Right
Only
+12 VDC
Ground
Remote
Input Mode
2 Ch. | 4 Ch.
Input Voltage
Low | High
Rem. | Offset | Signal
CH. 1
CH. 2
CH. 3
CH. 4
(L)
(R)
INPUT SEC
TION
Turn On Mode
PRE-
OUT
S
CH. 3
(L)
CH. 4
(R)
CH. 1
(L)
CHANNELS 1 & 2
CH. 2
(R)
Filter Mode
Filter Freq. (Hz)
Filter Freq. (Hz)
Off | HP | LP
Filter Mode
Off | HP | LP
Input Type
Input Sensitivity
Input Sensitivity
Stereo | Mono
Input Type
Stereo | Mono
4 Channel Amplifier
CHANNELS 3 & 4
Clipping
Clipping
Status
LED
(pg. 10-11)
Ch. 1 & 2
Clipping
Indicator
(pg. 7-8)
Ch. 3 & 4
Clipping
Indicator
(pg. 8)
Ch. 1 & 2
Filter Mode
Selector
(pg. 8)
Ch. 3 & 4 Filter
Frequency
Selector
(pg. 8)
Ch. 3 & 4
Filter Mode
Selector
(pg. 8)
Ch. 1 & 2
Input Type
(pg. 7)
Ch. 3 & 4
Input Type
(pg. 7)
Input
Mode
(pg. 7)
Input
Voltage
(pg. 7)
Turn-On
Mode
(pg. 6)
Ch. 1 & 2 Input
Sensitivity Control
(pg. 7-8)
Ch. 1 & 2 Filter
Frequency
Selector
(pg. 8)
Ch. 3 & 4 Input
Sensitivity Control
(pg. 7-8)