Installation Procedure; Speaker Selection - Kenwood KAC-7251 Mode D'emploi

■ Installation procedure

Since there are large variety of settings and
connections possible according to applications,
read the instruction manual well to select the
proper setting and connection.
1. Remove the ignition key and disconnect the
negative - terminal of the battery to
prevent short circuits.
2. Set the unit according to the intended usage.
3. Connect the input and output wires of the
units.
4. Connect the speaker wires.
5. Connect the power wire, power control wire
and grounding wire following this order.
6. Install the unit in the car.
7. Connect the negative - terminal of the
battery.
2WARNING
To prevent fire caused by a short in the wiring,
connect a fusible link or breaker nearby the
battery's positive terminal.
2CAUTION
• If sound is not output normally, immediately
turn power off and check connections.
• Be sure to turn the power off before
changing the setting of any switch.
• If the fuse blows, check wires for shorts,
then replace the fuse with one of the same
rating.
• Check that no unconnected wires or
connectors are touching the car body. Do
not remove caps from unconnected wires or
connectors to prevent short circuits.
• Connect the speaker wires to appropriate
speaker connectors separately. Sharing the
negative wire of the speaker or grounding
speaker wires to the metal body of the car
can cause this unit to fail.
• After installation, check that the brake
lamps, winkers, and wipers work properly.
■ Wiring
• Take the battery wire for this unit directly
from the battery. If it's connected to the
vehicle's wiring harness, it can cause blown
fuses etc.
• If a buzzing noise is heard from the speakers
when the engine is running, connect a line
noise filter (optional) to each of the battery
wire.
• Do not allow the wire to directly contact the
edge of the iron plate by using Grommets.
• Connect the ground wire to a metal part of
the car chassis that acts as an electrical
ground passing electricity to the battery's
negative - terminal. Do not turn the power
on if the ground wire is not connected.
• Be sure to install a protective fuse in the
power cord near the battery. The protective
fuse should be the same capacity as the
unit's fuse capacity or somewhat larger.
• For the power cord and ground, use a vehicle
type (fireproof) power wring cord with a
current capacity greater than the unit's fuse
capacity. (Use a power wiring cord with a
diameter of 5 mm 2 (AWG 10) or greater.)
• When more than one power amplifier are
going to be used, use a power supply wiring
wire and protective fuse of greater current-
handling capacity than the total maximum
current drawn by each amplifier.

■ Speaker Selection

• The rated input power of the speakers that
are going to be connected should be greater
than the maximum output power (in Watts) of
the amplifier. Use of speakers having input
power ratings that are less than the output
power of the amplifier will cause smoke to be
emitted as well as damage.
• The impedance of the speakers that are
going to be connected should be 2Ω or
greater (for stereo connections), or 4Ω or
greater (for bridged connections). When more
than one set of speakers are going to be
used, calculate the combined impedance of
the speakers and then connect suitable
speakers to the amplifier.
4Ω
4Ω
8 Ω
Combined impedance
4Ω 4Ω
2 Ω
7
English