JL Audio HD750/1 Owner's Manual page 4

Power and turn-on ConneCtions
Before installing the amplifier, disconnect the
negative (ground) wire from the vehicle's battery.
This will prevent accidental damage to the system,
the vehicle and your body during installation.
+12 VDC Ground +12 VDC Ground Remote Remote
+12V battery Connection
You will need to connect a power wire to
the vehicle's positive battery terminal, using an
appropriate power ring or specialized battery
terminal connector, such as the JL Audio
XB-BTU. This connection must be tight and
corrosion-free to ensure proper connectivity. This
wire MUST be fused appropriately for safety. Any
power wires run through metal barriers (such as
firewalls), must be protected with a high quality
insulating grommet to prevent damage to the
insulation of the wire. Failure to do so may result
in a dangerous short circuit.
Power wire requirements
The HD750/1's "+12 VDC" and "Ground"
connections are designed to accept 4 AWG power
wire. 4 AWG pure copper wire is recommended
for any power wire run longer than 72 inches (180
cm). For runs shorter than 72 inches, 8 AWG pure
copper power wire is acceptable.
If you are installing the HD750/1 with other
amplifiers and wish to use a single main power
wire, use 2 AWG or 1/0 AWG pure copper wire
as a main power wire. This 2 AWG or 1/0 AWG
power wire should terminate into a distribution
block mounted as close to the amplifiers as
possible and should connect to the HD750/1 with
4 AWG or 8 AWG pure copper power wire.
Please note that lower 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.).
6 | JL Audio - HD750/1 Owner's Manual
We do not recommend the use of "copper-
clad aluminum wire" or "CCA" wire because
this wire is significantly less conductive than
pure copper wire. Only use pure copper power
wire, such as JL Audio's MetaWire™. Tinned
copper wire (silver color) is acceptable as the
tin-plating is only a very minor component of
L
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the wire.
Inputs Preouts
Remote
Level
Fuse requirements
Control
R R
The installation of a fuse on each power wire,
within 18 wire inches (45 cm) of the positive
battery terminal is vital to protect the wire and
the vehicle from fire in the event of a collision or
short-circuit. 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
HD750/1 is being run from that power wire, we
recommend a 60A fuse be used. AGU (big glass
fuse). AFS (small blade fuse) or MaxiFuse™ (big
plastic-body fuse) types are recommended. If
other amplifiers are also being powered from the
wire and exceed 80 amps in total fuse rating, we
recommend the use of an ANL (large-blade) fuse
and holder. Please consult with your JL Audio
dealer to make sure that the wire, fuse holder and
fuse rating you have selected are appropriate for
your system's needs.
No fuse is required or recommended directly
before the amplifier power connection. If one is
desired, use a 60A AGU, AFS or MaxiFuse™ type
in an appropriate fuse block.
ground Connection
The chassis ground connection must be
made using 4 AWG or 8 AWG pure copper
wire 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 sanded at the contact point to create
a clean, metal-to-metal connection between
the chassis and the termination of the ground
wire with a brass or copper power ring. For
optimal grounding, we recommend the
use of a JL Audio ECS master ground lug
(XB-MGLU). Alternatively, a sheet metal
screw or bolt can be used with a star washer.
Many vehicles employ small (10 AWG - 6 AWG)
wire to ground the battery to the vehicle chassis
and to connect the alternator's positive
connection to the battery. To prevent voltage
drops, these wires should be upgraded to 4
AWG pure copper wire when installing amplifier
systems with main fuse ratings above 60A.
turn-on wire
The HD750/1 uses a conventional +12V remote
turn-on wire, typically controlled by the source
unit's remote turn-on output. The amplifier will
turn on when +12V is present at its "Remote"
input and turn off when +12V is switched off. If
a source unit does not have a dedicated remote
turn-on output, the amplifier's turn-on lead can
be connected to +12V via a switch that derives
power from an ignition-switched circuit.
The HD750/1's "Remote" turn-on connector
is designed to accept 18 AWG – 12 AWG wire. 18
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
bottom of the Power Connector Plug, using the
supplied 2.5 mm hex wrench. Strip 1/2 inch
(12mm) of wire and insert the bare wire into the
receptacle, 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 using the supplied
2.5 mm hex wrench, taking care not to strip the
head of the screw and making sure that the wire
is firmly gripped by the set screw.
amplifier Power Connector Plug
To connect the power wires and the remote
turn-on wire to the amplifier, unplug the power
connector plug from the amplifier chassis (pull
back firmly) and back out the set screws on
the connector plug, using the supplied 4 mm
hex wrench for the "+12 VDC" and "Ground"
connections and the supplied 2.5 mm hex wrench
for the "Remote" connection. Strip 3/8 inch (10
mm) of insulation from the end of each wire and
insert the bare wire into the receptacle on power
connector plug, seating it firmly so that no bare
wire is exposed. While holding each wire in place,
tighten each set screw firmly, taking care not to
strip the head of the screw.
Never make power connections with a "live"
wire. Always disconnect the negative battery
post before making any connections or
adjustments to a 12V power connection!
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