C ONNEC TION GUIDE
400W F ull-Range 4-Channel Class D Amplier
with Integrat ed DSP
with
Than k you for p urchasin g a JL Audi o amplif i er for yo ur soun d sys tem.
Y our ampli f ier has b een d esigne d and ma nufa ctu red to e xac ting
sta ndards i n orde r to ensure yea rs of musi cal enj oyment . For ma ximum
per f orman ce, we highl y recom mend th at you have your n ew ampli fi er
inst alle d by an autho rize d JL Audi o deale r . Y our autho rize d deale r has
the training, ex per tise and installation e quipment to ensure optimum
per f orman ce from t his pro duc t. Sho uld you de cide to i nsta ll the amp lif ier
your self, pl ease ta ke the tim e to read this m anual th oroug hly to fa miliari ze
yourself with it s installation requirements and se tup procedures.
If you have any qu esti ons reg arding t he inst ruc tions i n this manu al or any
aspe ct o f your amp lif ier ’s oper ation, p leas e contac t your a uthor ized J L
Audio d ealer f or assis tance. I f you ne ed fu rt her assis tan ce, pleas e contac t
the JL Audio T echnical Suppo rt Dep artme nt at t echnical@jlaudio.com or
call (954) 443 – 1 1 0 0 durin g busine ss hour s.
Installation Applications
This amplifier is designed for opera tion with 12 volt, negative-
ground electrical systems. Using this pr oduc t in systems with positive
ground and/or voltages other than 12V ma y result in damage to the
product and will void the warranty . This pr oduc t is not certified or
approved f or use in aircraft.
Product Description
This is a four-channel, full-range Class D amplifier equipped with the
second generation of JL Audio ’ s NexD2™ high-speed switching technology .
It is engineered to deliver ref erence -grade audio amplification with
outstanding efficiency and unprecedented, built-in pr ocessing power .
Instead of traditional analog processing contr olled by k nobs and switches,
VXi amplifiers feature an int egrated DSP (Digital Signal Proc essor). The
amplifier and its integrated DSP ar e configured using an external device
(PC, T ablet or Phone), with the appropriate JL Audio TüN™ application
installed. (See What is TüN? section for mor e info.)
Planning Y our Installation
It is impor tant that you take the time to r ead this manual thoroughly
and that you plan your installation car efully. It is very easy to damage
expensive vehicle syst ems in modern automobiles. Never assume that y ou
have found appr opriate wires without consulting a reliable wiring diagram
or without analyzing with proper test equipment. If you ar e uncomfortable
or unfamiliar with reading diagrams or testing methods , please enlist the
services of your authorized JL Audio dealer to perform the installation.
Y ou r autho rize d deale r has the tr ainin g, exp er tise a nd inst allati on
equi pment to e nsure opt imum pe r form ance fro m this pro duc t.
The
following are some c onsiderations that you must take into account when
planning your installation.
Safety Considera tions
• Install your amplifier in a dry, well-v entilated location that
does not interfere with your vehicle ’ s safety equipment
(air bags, seat belt systems , ABS brake systems, etc.).
• Do not mount the amplifier in the engine
compartment or in any areas of extreme heat.
• Securely mount the amplifier so that it does not come
loose in the event of a collision/sudden jolt or as a result
of repeated vibrations during normal operation.
• Check before drilling to make sur e that you will not be drilling into
a fuel tank, gas/brake line, wiring harness, or other vital system.
• Do not run system wiring outside or underneath the
vehicle/vessel. This is an extremely dangerous practice,
which can result in severe damage/injury .
• T ake the necessar y precautions when making
connections to the vehicle ’ s battery .
• Prot ect all system wires from sharp edges by car efully routing them,
tying them down and using grommets and loom where appr opriate.
• Secure all wiring as needed, using cable ties or wire clamps
to protect them from moving parts and sharp edges.
Cooling Efficiency Consider ations
The outer shell of your JL A udio amplifier is designed to remo ve heat
from the amplifier circuitry . F or 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 t o excessive
heat build-up and degraded performance. If an installation calls for an
enclosure around the amplifier , we rec ommend that this enclosure be
ventilated with the aid of a fan. In normal applications, fan-cooling is not
necessary. If mounting the amplifier under a seat, make sure ther e is at
least 1 inch (2.5 cm) of space above the amplifier’ s outer shell to permit
proper cooling.
What is Included
(1) Amplifier (1) Pow er Connec tor
(1) Analog Input/Pre-Out Harness (1) Speaker Output Harness
(1) JL Audio Badge (4) Corner Caps
(1) USB A/B Cable (6 ft./1.8 m) (1) Corner Cap T ool
(2) Black Hex Cap Machine Screws (1) 2.5 mm Hex Wrench
(2) Silver Thumbscrew s (1) 3 mm Hex Wrench
(1) Connection Guide
JL Audio Badge
T o complement the amplifier’ s mounting orientation, the logo badge
includes a recessed key fea ture allowing it to be affix ed at 90 degree
increments on the amplifier’ s top. T o install, remov e the adhesive backing
and press the badge at the desired orientation.
Corner Cap Installa tion and Removal
The corner caps are designed to c onceal the amplifier ’ s mounting holes
and hardware . T o install, simply press a corner cap into each mounting
hole. T o avoid scratching the amplifier’ s chassis during removal, use the
included, plastic corner cap tool and lift below each cap .
Making Connections
VXi amplifiers utilize removable plugs and harnesses to make the
following connections:
• Po wer C onnector
T o connect the power , ground and remot e turn-on wires to the amplifier ,
back out the set screws on the connector using the supplied hex
wrenches. Strip back 3/8 inch (10 mm) of insulation fr om the end of each
wire and insert the bare wire into the rec eptacle on the power connector
plug, seating it firmly so that no bare wir e is exposed. While holding each
wire in place, tigh ten each set screw firmly , tak ing care not to strip the
head of the screw . Install the power connector by plugging it into the
amplifier’ s power connector receptacle, pushing firmly .
• Analog Input/Pre-Out Harness
This harness includes connections for Signal Input (RCA plugs), Preamp
Outputs (RCA plugs), Remote T urn- On Output (wire lead) and Valet Input
(wire lead). Select either the included black hex cap machine screws or
the silver thumbscrews t o secure the Analog Input Harness connector to
the amplifier .
• Speaker Output Harness
This harness includes output wire leads to connect with speaker cables.
T urn-On M ode
VXi amplifiers can be switched on and off using one of three methods,
configured by the “ T urn On M ode ” setting in the T üN™ Software Inter face.
Refer to the table below f or detailed info and decide which option is best
suited for your specific sy stem.
Setting Mode Function Connection
Remote
Conventional
(Preferr ed)
T urn-on/off controlled by your
source unit.
Connect your source unit’s
+12V remote turn-on output to
the Pow er Connector’s Remote
T urn-On Input connection.
DC
Offset
DC Offset
Sensing
(Auto)
Automatically turns on by
detecting the presence of small
DC signal in OEM audio outputs
and turns off (within 5 minutes)
after the signal is removed.
This circuit senses the Analog
Input 1 only. Note: The sensitivity
of this circuit is designed for
high-level (speaker level) signals,
not for low-level (pr eamp level)
signals. Make sure the OEM
audio outputs contain midrange
signals.
Signal
Signal
Sensing
(Auto)
Automatically turns on by detecting
full-range OEM audio signals and
turns off (within 5 minutes) after
the signal is removed (varies ,
depending on input signal levels).
3
Speaker Output Harness
Connect the speaker output leads to the corresponding speaker wires .
4
JLid-COMM
Connect optional accessories ( VXi-BT C, VXi-HUB, etc.) to this port.
5
JLid-CTRL
Conne ct o ption al DRC (D igita l Remo te Controll er) wire d control lers
to this p or t.
6
SD + Reset
Lift the dust cover to access the f ollowing utility func tions:
Reset Buttons: Use a small pin to perform the following:
Reboot Amp - Press and r elease the r ight button.
Factory Reset (wipe memor y , reboot amp) - Press and hold the left
button for 7 seconds .
Micro SD Slot: F or ser vice/future expansion.
7
USB
This USB A / B por t pe rmit s conne c tion to a comp uter fo r conf igur ation
and tun ing, usi ng the TüN™ S of tw are.
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D I G I TA L - I n
T osli nk por t acce pts 2- chann el digi tal aud io signa l from a ny optica l
(S/PDIF) d igita l outp ut, wit h a samp le rate up to 19 2 k Hz .
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D I G I TA L - O u t
Provid es a digi tal aud io outp ut (24 bit/9 6 kHz) th at is not sus ceptib le to
RF interference or noise -g enerating electrical conditions. By default, this
is a pass- throu gh audio o utpu t, with n o signal p rocess ing app lied , and
intend ed fo r use wit h other e quipm ent that have an o ptic al (Toslink)
digit al audi o input (S/PD IF) p or t. Using th e TüN™ Sof t ware I nter face, yo u
may conf igur e this out put ’s routing , equa lizat ion, o utput l evel and D RC
control functionalit y .
1
Po wer Connector
The VX400/4i’ s “+12 VDC” and “Ground” connections are designed to
accept 4 A WG copper wire. Not e: Copper Clad Aluminum (C CA) wire is not
recommended. 4 A WG is the required copper wire size f or this amplifier .
A. Run copper wire from the positiv e (+12V ) battery post to the amplifi-
er mounting location. If additional amplifiers are being installed, run
the appropriate gauge copper wir e for the combined, maximum cur-
rent draw , and install a fused distribution block near the amplifiers.
B. An appropriate fuse (sold separately) at the main po wer wire(s) is
vital for vehicle saf et y . This fuse must be installed within 18 inches
(45 cm) of the battery post connection. I f this is the only device con-
nected to this main wire, use a 40 A fuse . Do not install the fuse until
the power wire has been secur ely connec ted to the amplifier .
C. The ground connection should be made to a clean, solid metal
grounding point using copper wir e, and kept as shor t as possible.
The metal surface of the grounding point should be sanded to create
a clean, metal-to-metal connection. For optimal grounding , we
recommend using a JL Audio ECS mast er ground lug (XB-MGL U). All
ground connections (source unit and amplifiers) should be made
at the same location.
D. The remote connection should be made to the source unit’ s positive
(+12V ) remote turn-on output. If your source unit does not have a
dedicated remote turn-on output, consider one of the alternative
turn-on options. (See T urn- On Mode section for more info .)
2
Analog Input/Pre-O ut Harness
The Analog Input Harness accepts the following c onnections:
Line-Level Analog Inputs: Four f emale RCA jacks feed a differential-
balanced input section, providing a high degree of input flexibility , and
retaining superior noise rejection. This type of input architecture also
allows the VX400/4i to cleanly accept any analog audio signal up to 16
VRMS, without using a line- output converter .
Preamp Outputs: Tw o female, RCA jacks deliver line-level, analog audio
outputs (Max 4 V RMS) tha t are compatible with most types of aftermarket
equipment. These are configured with the T üN
™
Software Inter face.
Remote: This connection provides a positive (+12V ) turn-on voltage
(475 mA limit) to activate other aftermarket equipment (similar to an
aftermarket head unit ’ s remote turn- on lead).
V alet: When connected to negativ e ground, this c onnection activates the
V alet Mode Preset and will r emain active until the ground connection is
removed . This preset is c onfigured using the TüN
™
Software Inter face and
will override any DRC contr olled preset.
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