10
| JL Audio - 300/4
v3
Owner’s Manual
11
sYstem ConFigurations
The 300/4v3 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
drawings on Page 22 to mark the required switch
positions for easy reference.
bi-amPliFied sYstems
Bi-amplified systems are defined as systems
in which separate amplifier channels drive low-
frequency (LF) and high-frequency (HF) speakers
and are separately filtered to send appropriate
frequency ranges to each speaker system.
The most common application of
bi-amplification in mobile audio is to drive a
subwoofer system from one or more amplifiers or
channels and component speakers from separate
amplifiers or channels.
The 300/4v3 can be configured to drive a
bi-amplified system by itself or with a separate
subwoofer amplifier.
bi-amplified system with one 300/4v3
In this configuration, the rear channels of the
300/4v3 will drive subwoofers (stereo 75W x 2 or
bridged 150W x 1) with low-pass filtering. The
front channels will drive component speakers in
stereo (75W x 2) with high-pass filtering.
Input connection options for a bi-amplified system
with one 300/4 v2 are as follows:
A) No User Adjustability:
Req uired: a basic source unit or processor with
one pair of stereo outputs.
Inp ut Connections: a single pair of stereo
source unit outputs connected to the
front channel inputs of the 300/4v3
(select “2ch” on the “Input Mode”
switch in the “Front Input Section”).
Res ult: the relative level of the LF and HF
channels will be fixed by the 300/4v3’s “Input
Sens.” settings and will not be user adjustable
from the front of the vehicle.
B) Fade Subwoofer Level vs. HF Level
Req uired: a source unit or processor with front
and rear pairs of outputs.
Inp ut Connections: the first stereo pair of source
unit outputs is connected to the front inputs
of the 300/4v3. The second stereo pair of
source unit outputs is connected to the rear
inputs (select “4ch” on the “Input Mode”
switch in the “Front Input Section”).
Res ult: 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.
C) Subwoofer Level Control Only
Req uired: a source unit or processor with left,
right and subwoofer outputs.
Inp ut Connections: the main stereo pair of
source unit outputs is connected to the front
inputs of the 300/4v3. The source unit’s
dedicated subwoofer output is connected to
the rear inputs (select “4ch” on the “Input
Mode” switch in the “Front Input Section”).
Res ult: in this mode, the user has the ability to
control the absolute level of the LF channels
relative to the HF channels.
I M P O R TA N T
!
Set the rear channel “Input Sens.” with the
source unit’s subwoofer level control set at
3/4 of full output. See Appendix A (page 14)
for details.
status indiCator ligHts /
ProteCtion CirCuitrY
There are three status indicator lights on the
top of the amplifier. These are as follows:
1) “Power” (Green): lights to indicate that the
amplifier is turned on and operating normally.
2) “Thermal” (Red): lights to indicate that
the amplifier has exceeded its safe operating
temperature, putting the amplifier into a self-
protection mode, which reduces the power
output of the amplifier. The red light will shut
off and the amplifier will return to normal,
full-power operating mode if the heat sink
temperature drops back to a safe level.
3) “Low Ω” (Amber): lights to indicate that the
impedance of the speaker load connected to
the amplifier is lower than the optimum load
impedance range for the amplifier. When this
light is on, a protection circuit engages and
reduces the power output of the amplifier.
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).
There is only one condition that will shut down
an undamaged 300/4v3 completely… If battery
voltage drops below 10 volts, the entire amplifier
will shut itself off. The green “Power” indicator
on the top of the amplifier 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, have your charging system
inspected to make sure it is working properly.
For information on troubleshooting this
amplifier, refer to Appendix E (page 20).
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