JL Audio Slash v2 300/4V2, 300/4v2 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 and extended warranty

coverage, 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 [phone] during business hours.

OWNER’S MANUAL

four-channel full-range amplifier

2 | JL Audio - 300/4v2 Owner’s Manual

3

Cooling Efficiency Consid erations:

Your JL Audio amplifier employs an
advanced type of heat management, cal led
RealSink™. This feature takes advantage of
convection and radiation effects to remove
heat from the amplifie r circuitry. For opt imum
cooling performance, the vertical heat sinks
located at the back of the amplifier shou ld 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 a nd degraded per formance. If a n
insta llation cal ls for an enclosure around the
amplif ier, we recommend that this enclosure
be ventil ated with the aid of a fan. I n normal
applications, fan-cooling is not necessary, but
you sti ll need to follow s ome basic guidel ines:

• Amplifier mounted vertically with heat sink fins

pointing up: Optimum

• Amplifier mounted horizontally,

right side up: Good

• Amplifier mounted horizontally, but upside

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

• Amplifier mounted vertically with heat sink fins

pointing lateral ly: Fair

• Amplifier mounted vertically with heat sink fins

pointing down: Poor (not recommende d)

If mounting the amplifier under a seat,
make su re there is at lea st 1 inch (2.5 c m) of
space above the amplif ier’s outer shel l to permit
proper coolin g.

Safety Considerations:

Your amplifier needs to be installed in a dry,
well-ventila ted environment a nd 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 ampli fier using appropr iate
hardware so that it does not come loose in t he
event of a co llision or a sudden jolt to the vehicle.

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
harnes s or other vita l vehicle system.

• Do not run system wiring outside or underneath

the vehic le. This is a n extremely da ngerous
practice which can result in severe damage to
your vehic le 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

compart ment, under the ve hicle, on the roof
or in a ny other area th at will exp ose the
amplifier circuitry to the elements.

PROTECT YOUR H EARING!

We value you as a long-term customer. For
that rea son, we urge you to pr actice restra int in
the oper ation of this produc t so as not to d amage
your hearing and that of others in your vehicle.
Studies have shown that cont inuous exposure to
high sound pressure levels can lead to permanent
(irrepara ble) hearing loss . This and a ll other
high-power a mplifiers ar e capable of producing
such hig h sound pressure le vels when connect ed
to a spea ker system. Plea se limit your continuous
exposu re to high volume le vels.

While driving, operate your audio system in
a manner that stil l allows you to he ar necessar y
noises to operate your vehicle safely (horns,
sirens, etc.).

SERIAL NUMBER

In the event that your a mplifier requi res
serv ice or is ever stolen, you will nee d 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 bot tom panel of the
amplif ier and on the amplifier pac kaging.

Serial Number:

INSTALLATION APPLICATIONS

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
th e w arr ant y.

This product is not certified or approved for
use in aircraft.

Do not att empt to “bridge” t he outputs of th is

amplif ier with the outputs of a second amplifier,
includin g an identical one.

PLANNING YOUR INSTALLATION

It is important that you take the time to read
this m anual and t hat you plan out your
insta llation caref ully. The followi ng are some
considerat ions that you must t ake into account
when plan ning your ins tallation.

Front Channel
Input Voltage

Range Selector

(pg. 6)

Front Channel

Filter Slope

Selection

(pg. 8)

Front Channel

Filter Frequency

Range Selector

(pg. 8)

Front Channel
Left and Right

Input Jacks

(pg. 6)

Rear Channel
Left and Right

Input Jacks

(pg. 6)

Front Channel

Input Mode

Selector

(pg. 6)

Remote Turn-On

Connector

(pg. 6)

Chassis Ground

Connector

(pg. 5)

+12 V Power

Connector

(pg. 5)

Front Channel

Speaker Outputs

(pg. 9)

Rear Channel
Input Voltage

Range Selector

(pg. 6)

Rear Channel

Filter Slope

Selection

(pg. 8)

Rear Channel

Filter Frequency

Range Selector

(pg. 8)

Rear Channel

Input Sensitivity

Control
(pg. 6)

Rear Channel

Speaker Outputs

(pg. 9)

Front Channel

Filter Cuto

Frequency Selector

(pg. 8)

Front Channel

Filter Mode

Selector

(pg. 7)

Rear Channel

Filter Mode

Selector

(pg. 7)

Rear Channel

Filter Cuto

Frequency Selector

(pg. 8)

Front Channel

Input Sensitivity

Control

(pg. 7)

Bridged

Left Right

+12VDC Ground Remote Front Filter Controls Front Input Section Front Speaker Outputs

Bridged

Left Right

Rear Speaker Outputs

Left Ch. Right Ch.Filter Freq. (Hz)

Filter Slope

Freq. Range

Input Voltage Input Sens. Input Mode

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10 Low | High

Rear Input Section

Left Ch. Right Ch.

Input Voltage Input Sens.

Low | High 2ch | 4ch

50

60

7595130

200

500

300 /4v2

Four-Channel Full-Range Amplifier

Rear Filter Controls

Filter Freq. (Hz)

Filter SlopeFreq. Range

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10

50

60

7595130

200

500

4 | JL Audio - 300/4v2 Owner’s Manual

5

POWER CONNECTIONS

Before instal ling the amplifier,
disconnect t he negative (ground) wire
from the veh icle’s battery. Th is will prevent
accidental damage to the system, the vehicle
and your pers on during installation.

Bridged

Left Right

+12VDC Ground Remote Front Filter Controls Front Input Section Front Speaker Outputs

Bridged

Left Right

Rear Speaker Outputs

Left Ch. Right Ch.Filter Freq. (Hz)

Filter Slope

Freq. Range

Input Voltage Input Sens. Input Mode

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10 Low | High

Rear Input Section

Left Ch. Right Ch.

Input Voltage Input Sens.

Low | High 2ch | 4ch

50

60

7595130

200

500

300 /4v2

Four-Channel Full-Range Amplifier

Rear Filter Controls

Filter Freq. (Hz)

Filter SlopeFreq. Range

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10

50

60

7595130

200

500

The 30 0/4v 2’s “+1 2 VD C” a nd “Ground”

connections are designed to accept 8 - 4
AWG power w ire. 8 AWG is the minimum

recommended power wire size for this amplifier.

If you are installing the 300/4v2 with other
amplif iers and wish to use a single main power
wire, use 2 AWG or 1/0 AWG main power wire
(depending on the overall current demands of
all the amplifiers in the system). This 2 AWG
or 1/0 AWG power wire shou ld terminate i nto
a distribution block mounted as close to the
amplifiers as possible and should connect to the
300/4v2 with 8 - 4 AWG power wire.

Note: that 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.).

To connect the power wires to the amplifier,
first back out the set screw on the top of the
amplif ier, using the suppl ied 2.5 mm hex
wrench. Strip 1/2 inch (12 mm) of insulation
from the end of each wire and insert the bare
wire i nto the receptacle on the front panel
of the a mplifier, seatin g 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 he ad of the screw.

The ground connection should be made using
the sa me gauge wire as t he 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 sande d at the contact p oint to create a clea n,
metal-to-me tal connection between the chassis
and the termination of t he ground wire. For
optimal g rounding, we recommend the u se of a
JL Audio ECS ma ster ground lug (XB-MGLU).
Alternat ively, a sheet metal screw or bolt can be
used with a star washer.

Any wires run through metal barriers (such as
firewa lls), must be protec ted with a hi gh quality
insulat ing grommet to prevent damage to t he
insulation of the wire. Failure to do so may result
in a dangerous short circuit.

IMPORTANT

!

Many vehicles employ small (10 AWG -
6 AWG) wire to ground the battery to the
vehicle chassis and to connect the alternator’s
positive con nection to the bat tery. To prevent
voltage drops, these wires should be upgr aded
to 4 AWG when installing amplif ier systems
with ma in fuse rati ngs above 60A.

FUSE REQUIREMENTS

It is absolutely vital that the main power
lead 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 300/4v2 is being run from
that power wire, we recommend a 40A fuse
be used . AGU (big g lass fuse), Max iFuse™
(big plas tic-body fuse) or A FS (mini­blade fu se) ty pes are recommende d.

No fuse is required or rec ommended direct ly
before the amplifier power connection. If one is
desired, we recommend the u se of a 40A AGU,
AFS or Ma xiFuse™ t ype fuse.

PRODUCT DESCRIPTION

The JL Aud io 300/4v2 is a four- channel ful l-

range a mplifier uti lizing patented A bsolute

Symmet ry™ Class A /B technology for all
channel s. All chan nels benefit f rom JL Audio’s
exclusive R.I.P.S. power supply design which

optimi zes the output of each channel pa ir for any

impedance between 1.5 and 4 ohms per channel.
The 300/4v2 can be operated in the
following modes:

1) As a fu ll-system ampl ifier in bi-amp mode with
one pair of channels dr iving subwoofers i n low­pass mode (75W x 2 or 150W x 1) and the other
pair of channels driv ing main sp eakers in hig h­pass mode (75W x 2).

2) As a four-channel satellite amplifier in a
bi-amplif ied system, del ivering high-pa ssed
signals to front and rear speaker systems.

The 300/4v2’s flexible input and crossover
sections permit operation with a wide variety
of source u nits and sys tem configur ations. The
300/4v2 can operate with a single pair of stereo
inputs or w ith separate inputs for front and rear
channels, if the source unit is equipped with front
and rea r outputs.

TYPICAL INSTALLATION SEQUENCE

The following represents the sequence
for a ty pical amplif ier instal lation, using a n
after market source u nit or OEM Interfa ce
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 dea ler for assista nce.

1) D isconnect the ne gative battery post

connection and secure the disconnected cable
to prevent accidental re-connection during
insta llation. 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
damage d and will not interfere with
vehicle oper ation. Use 2 AWG or 1/0
AWG power w ire if additiona l amplifiers
are being installed with the 300/4v2.

3) Connect power wire to the positive battery

post. Fuse the wire with an appropriate fuse
block (and con nectors) within 18 inches (45
cm) wire length of the positive battery post.

This f use is essenti al to protect t he vehicle. Do

not install the fuse until the power wire has
been conne cted to the a mplifier.

4) Run signal cables (RCA cables) and remote

turn-on wire from the source unit to the
amplifier mounting location.

5) Run speaker wire from the speaker systems to

the ampl ifier mounti ng location.

6) Find a good, sol id metal grou nding point clos e

to the amplifier and connect the negative power
wire to it using appropriate hardware. Use
minimum 8 AWG power wire, no longer than
36 inches (90 cm) from the amplifier to the
ground connection point. In some vehicles, it
may be nece ssary to upg rade the bat tery ground
wire. (See page 5 for important notice).

7) Securely mount the amplifier using

appropriate hardware.

8) Connect the positive and negative power

wires to the amplifier. A fuse near the
amplif ier is not necess ary.

9) Connect the remote turn-on wire

to the a mplifier.

10) Connect the RCA input cables

to the a mplifier.

11) Conne ct the speak er wires to t he amplifier.
1 2 ) C arefully rev iew the ampli fier’s control

settings to make sure that they are set
according to the needs of the system.

1 3 ) Install power wire fuse (40A for a

single 300/4v2) and reconnect the negative
battery post terminal.

14) Turn on the source un it at a low level

to double-check that the amplifier is
config ured correct ly. Resist t he temptation
to crank it up until you have verified the
control set tings.

15) Make necessary adjustments to the input

sensitivity controls to obtain the right
overall output and the de sired balance
in the system. See Appendix A (page 14)
for the recommended input sensitivity
setting method.

1 6 ) Enjoy the fruits of your labor wit h your

favorite music .

6 | JL Audio - 300/4v2 Owner’s Manual

7

IMPORTANT

!

The output of the amplifier will decrea se
for a given input voltage when the “Input
Range” switch is placed in the “Hig h”
position. Conversely, the output will be
higher with the switch in the “Low” position.
While this may sound counter-intuitive, it is
correct as described.

3) Input Se nsitivity Adjust ment: Located next

to the “I nput Voltage” switch in each input
section is a rotary c ontrol labeled “Input
Sens.”. Once the appropriate “Input Voltage”

range has been selected, this control can be
used to m atch the source u nit’s output voltage
to the input stage of each pair of amplifier
channel s for maximum clean output. Rota ting
the contr ol clockwise w ill result in higher
sensitivity (louder for a given input voltage).
Rotating the control counter- clockwise w ill
result in lower sensitivity (quieter for a given
input voltage). To properly se t each pair
of amplifier channels for maximum clean
output, please refer to Appendix A (page 14)
in th is manual. A fter using t his procedure,
you can then adjust the re lative level of each
channel pair by adjusting the input sensitivity
downward on either or both channel pairs, if
they require attenuation to achieve the desired

system ba lance. Do not i ncrease the “Input
Sens.” setting for any amplifier in the system

beyond the maximum le vel established du ring
the procedure outlined in Appendix A (page

14). Doing so will result in audible distortion

and possible speaker damage. Be aware that

both “Input Sens.” adjustments will have to

be made, regardless of how many input cables
are feed ing the ampli fier. These control s will
allow you to set the appropriate relative levels
for front and rear channels and any other
amplif ier channels i n the system.

CROSSOVER CONTROLS

Crossovers a re groups of indi vidual elect ronic
filters which allow only certain frequency
ranges to pass through them by attenuating
frequencies outside the selected range. These
filters allow the user to specify what frequency
range w ill be sent out of each channel s ection
of the amplifier. This, in turn, allows each
speaker system to only re produce a range of
frequencies it is well-suited for, resulting in
reduced di stortion and i mproved fidelity.

Front And Rear Filter Section:

Bridged

Left Right

Left Ch. Right Ch.Filter Freq. (Hz)

Filter Slope

Freq. Range

Input Voltage Input Sens. Input Mode

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10 Low | High

|

4ch

50

60

7595130

200

500

Bridged

Left Right

Bridged

Left Right

Rear Speaker Outputs

Left Ch. Right Ch.Filter Freq. (Hz)

Filter Slope

Freq. Range

Input Voltage Input Sens. Input Mode

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10 Low | High

Rear Input Section

Left Ch. Right Ch.

Input Voltage Input Sens.

Low | High 2ch | 4ch

50

60

7595130

200

500

Rear Filter Controls

Filter Freq. (Hz)

Filter SlopeFreq. Range

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10

50

60

7595130

200

500

The 300/4v2 employs two separate, but
identical filter sections for its front and rear
channel pairs. These sections consist of the
followin g controls

1) “ Filter M ode” Control: Th is switch al lows you

to conf igure the f ilter into one of t wo filter
type s or to defeat it complet ely:

“Off”: Defeats the filter for that channel

section completely, a llowing the full range of
frequencie s present at the input s to feed that
pair of channels. This is useful for systems

utili zing outboard cro ssovers or requir ing full-

range repro duction from th at pair of chan nels.

“LP” (Low-Pass): Configures the filter to

attenuate frequencies above the selected
filter frequency. Useful for connection of
subwoofer(s) to that c hannel section .

“HP” (High-Pass): Configures the filter to

attenuate frequencies below t he selected
filter frequency. Useful for connection
of component speakers to that channel
section in a bi-amplif ied system.

TURNON LEAD

The 30 0/4v 2 uses a conventiona l +12V remote
turn-on lead, typically controlled by the source
unit’s remote turn-on output. The amplifier will

turn on when +12V is prese nt at its “ Remote”

input and turn off when +12V is switched off. If
a source u nit does not have a dedicated remote
turn-on output, the amplifier’s turn-on lead can
be connec ted to +12V via a switch that derives
power from an ignition-switched circuit.

The 30 0/4v 2’s “Remote” turn-on connector is

designed to accept 18 AWG – 8 AWG wire.
12 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 top
of the amplifier, using the supplied hex wrench.
Strip 1/2 inch (12mm) of wire and insert the
bare wire into the receptacle on the front panel
of the amplifier, 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, taking care not to
strip the head of the screw and making sure that
the wi re is firm ly gripped by t he set screw.

FRONT AN D REAR IN PUT SECTIONS

The 300/4v2 has two separate input sections,
one for its front channels and another for its rear
channel s. Each sect ion contains a pa ir of RCA-

type input jacks, a n “Input Voltage” switch and
an “Input S ens.” rotary cont rol.

Bridged

Left Right

Left Ch. Right Ch.Filter Freq. (Hz)

Input Voltage Input Sens. Input Mode

|

High

|

4ch

Bridged

Left Right

Bridged

Left Right

Rear Speaker Outputs

Left Ch. Right Ch.Filter Freq. (Hz)

Filter Slope

Freq. Range

Input Voltage Input Sens. Input Mode

12dB | 24dB

Filter Mode

Off | LP | HP

x1 | x10 Low | High

Rear Input Section

Left Ch. Right Ch.

Input Voltage Input Sens.

Low | High 2ch | 4ch

50

60

7595130

200

500

The “Front Input Section” also contains an
“Input Mode” switch to allow operation of all

four amplifier channels with one or two pairs of
input sign als.

1) Input Mode Switch: If you wish to operate

all fou r channels of t he 300/4v2 with a single

pair of stereo inputs, select the “2ch” position
on the “I nput Mode” switch and connect a

single p air of input cable s to the input jack s

in the “Front Input Section”. In this mode,

the ampl ifier wil l route the signa ls connected
to the f ront inputs to the re ar inputs as wel l.
If you wish to use separate inputs for the front
and rea r channel sect ions (to allow front-to­rear fading, for example) and the source unit
is equipped with front and rear outputs, select

“4ch” on the “Input Mode” switch. In this

mode, you mu st connect sepa rate pairs of i nput
cables to each input sect ion.

2) Input Voltage R ange: A wide range of signal

input voltages can be accommodated by each of
the 300/4v2’s input sections (200mV – 8V).
This wide range is split up into two sub-ranges,
accessible via switches located in each input
section of the amplifier. Be aware that each

input sec tion’s “Input Voltage” switch will

have to be configured, regardless of how many
input cables are actually feeding the amplifier.

The “Low ” position on eac h “Input Voltage”

switch s elects an input sensitivity r ange
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, with conventional
preamp-level outputs, this is most likely the

position t hat you will use. The “High” position
on each “I nput Vo ltage” 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 sourc e units and sm all amplif iers. 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 i nput pair or use
the JL Audio ECS Speaker Wire to RCA
adaptor (XB-CLRAIC2-SW).