2
Choose a mounting location in the trunk or
cargo area where the amplifier will not be dam-
aged by shifting cargo. Amplifier cooling is
essential for proper amplifier operation. If the
amplifier is to be installed in an enclosed space,
make sure there is sufficient air circulation for
the amplifier to cool itself.
When mounting the amplifier under a seat,
ensure that it is clear of all moving seat parts
and does not affect the seat adjustments. Mount
the amplifier so it is not damaged by the feet
of backseat passengers. Make sure that the
amplifier is mounted securely using nuts and
bolts or the supplied mounting screws.
Mount the amplifier so that it remains
dry – never mount an amplifier outside
the vehicle or in the engine compartment.
I
NTRODUCTION
WARNING!
Playing loud music in an automobile can hinder
your ability to hear traffic and permanently
damage your hearing. We recommend listening
at low or moderate levels while driving your
car. Infinity accepts no liability for hearing loss,
bodily injury or property damage resulting from
the use or misuse of this product.
IMPORTANT
To get the best performance from your Reference
Series amplifiers, we strongly recommend
that installation be entrusted to a qualified
professional. Although these instructions explain
how to install Reference amplifiers in a general
sense, they do not show specific installation
methods that may be required for your particular
vehicle. If you do not have the necessary tools or
experience, do not attempt the installation your-
self. Instead, please ask your authorized Infinity
car audio dealer about professional installation.
INSTALLATION WARNINGS AND TIPS
•
Always wear protective eyewear when using
tools.
•
Turn off the audio system and other electrical
devices before you start. Disconnect the (–)
negative lead from your vehicle’s battery.
•
Check clearances on both sides of a planned
mounting surface before drilling any holes or
installing any screws. Remember that the
screws can extend behind the surface.
•
At the installation sites, locate and make a note
of all fuel lines, hydraulic brake lines, vacuum
lines and electrical wiring. Use extreme caution
when cutting or drilling in and around these
areas.
•
Before drilling or cutting holes, use a utility
knife to remove unwanted fabric or vinyl to
keep material from snagging in the drill bit.
•
When routing cables, keep input-signal cables
away from power cables and speaker wires.
•
When making connections, make certain they
are secure and properly insulated.
•
If the amplifier’s fuse must be replaced, use
only the same type and rating as that of the
original. Do not substitute another kind.
The Reference amplifiers are capable of
delivering high power levels, and require a
reliable connection to the vehicle’s electrical
system in order to perform optimally. See
Figure 1 for connection location. Please
adhere to the following instructions carefully.
GROUND CONNECTION
Connect the amplifier’s Ground (GND) terminal
to a solid point on the vehicle’s metal chassis,
as close to the amplifier as possible. Refer to the
chart below to determine minimum wire-gauge
size. Sand away any paint from this location; use
a star-type-lock washer to secure the connection.
POWER CONNECTION
Connect a wire (see chart at right for appropriate
gauge) directly to the vehicle’s positive battery
terminal, and install an appropriate fuse holder
within 18" of the battery terminal. Do not
install the fuse at this time. Route the wire to
the amplifier’s location, and connect it to the
amplifier’s positive (+12V) terminal. Be sure to
use appropriate grommets whenever routing
wires through the firewall or other sheet metal.
Failure to adequately protect the positive wire
from potential damage may result in a vehicle
fire. When you are done routing and connecting
this wire to the battery and to the amplifier,
you may install the fuse at the battery. The
fuse value should be selected based on total
amplifier-current draw; see chart at right.
REMOTE CONNECTION
Connect the amplifier’s Remote (REMOTE)
terminal to the source unit’s Remote Turn-On
lead using a minimum of 18-gauge wire. If your
source unit does not have a remote turn-on
connection, connect the amplifier’s (REMOTE)
terminal to the vehicle’s accessory circuit.
WIRE-GAUGE CHART
Amplifier
Maximum
Minimum
Model
Current Draw
Wire Gauge
7521a
34A #8
AWG
7541a
85A #8
AWG
5761a
87A #8
AWG
311a
40A #8
AWG
611a
69A #6
AWG
1211a
115A #4
AWG
These recommendations assume 7' – 10' wire
runs. If your installation differs markedly, you
will need to adjust the wire gauge accordingly.
SPEAKER CONNECTIONS
Refer to the application guides on the pages
that follow. Speaker connections should be
made using a minimum of 16-gauge wire.
HIGH-LEVEL INPUT CONNECTIONS
The 7521a, 7541a and 5761a amplifiers are
equipped with speaker-level inputs that allow
you to add an amplifier to head units that do
not have RCA line outputs. The speaker outputs
for the source unit should be connected to the
amplifier using the supplied connector (square
four-wire plug). Remember to check for proper
polarity. The 311a, 611a and 1211a amplifiers
are not equipped with high-level inputs.
NOTE:
When using the low-level or high-level
inputs, the AUX outputs can be used to pass a
full-range line-level signal to another amplifier.
Figure 2.
Speaker-level connector.
P
OWER
C
ONNECTIONS
Figure 1.
Terminal-connection end plate.
C
HOOSING A
L
OCATION AND
M
OUNTING THE
A
MPLIFIER
HIGH-LEVEL
INPUT
Speaker Wires
(spliced)
R
L
+
R
–
+
L
–
+ WHITE
– WHITE/BLACK
GRAY/BLACK –
GRAY +