Kenwood KAC-718 User Manual

KAC-718

© B64-1357-00 (EM)

MONO POWER AMPLIFIER

INSTRUCTION MANUAL

2

English

Safety precautions

To prevent injury or fire, take the following
precautions:

• When extending the ignition, battery, or
ground wires, make sure to use automotive­grade wires or other wires with a 3mm

2

(AWG12) or more to prevent wire
deterioration and damage to the wire
coating.

• To prevent a short circuit, never put or leave
any metallic objects (such as coins or metal
tools) inside the unit.

• If the unit starts to emit smoke or strange
smells, turn off the power immediately and
consult your Kenwood dealer.

• Do not touch the unit during use because the
surface of the unit becomes hot and may
cause burns if touched.

To prevent damage to the machine, take the
following precautions:

• Be sure the unit is connected to a 12V DC
power supply with a negative ground
connection.

• Do not open the top or bottom covers of the
unit.

• Do not install the unit in a spot exposed to
direct sunlight or excessive heat or humidity.
Also avoid places with too much dust or the
possibility of water splashing.

• When replacing a fuse, only use a new one
with the prescribed rating. Using a fuse with
the wrong rating may cause your unit to
malfunction.

• To prevent a short circuit when replacing a
fuse, first disconnect the wiring harness.

• If you experience problems during
installation, consult your Kenwood dealer.

• If the unit does not seem to be working
right, consult your Kenwood dealer.

Cleaning the unit

If the front panel gets dirty, turn off the power
and wipe the panel with a dry silicon cloth or
soft cloth.

Do not wipe the panel with a hard cloth or a
cloth dampened by volatile solvents such as
paint thinner and alcohol. They can scratch the
surface of the panel and/or cause the indicator
letters to peel off.

Accessories

2CAUTION

NOTE

2CAUTION

2WARNING

Part name

Number
of Items

External

View

Round terminal

(Large)

1

Round terminal

(Medium)

2

Round terminal

(Small)

1

Terminal cover

(Power terminal)

1

Self-tapping screws

(ø4 × 16 mm)

4

English

3

Installation procedure

Installation

Since the power amplifier has no parts which require operation, it can be installed at a position
away from the driver’s seat without any hindrances.
As generally accepted positions for its installation, places such as inside the trunk, etc. can be
considered.

• Do not install the unit under the carpet. Otherwise heat build-up occurs and the unit may be
damaged.

• Install this unit in a location which allows heat to easily dissipate.
Once installed, do not place any object on top of the unit.

• The surface temperature of the amplifier will become hot during use. Install the amplifier in a
place where people, resins, and other substances that are sensitive to heat will not come into
contact with it.

• When making a hole under a seat, inside the trunk, or somewhere else in the vehicle, check
that there is nothing hazardous on the opposite side such as a gasoline tank, brake pipe, or
wiring harness, and be careful not to cause scratches or other damage.

• Do not install near the dashboard, rear tray, or air bag safety parts.

• The installation to the vehicle should securely fasten the unit to a place in which it will not
obstruct driving. If the unit comes off due to a shock and hits a person or safety part, it may
cause injury or an accident.

• After installing the unit, check to make sure that electrical equipment such as the brake lamps,
turn signal lamps and windshield wipers operate normally.

2CAUTION

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,

Installation board, etc.
(thickness : 15 mm or more)

Self-tapping screw
(ø4 × 16 mm)

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 cables of the units.

4. Connect the speaker cables.

5. Connect the power cable, power control cable and grounding cable following this order.

6. Install the unit in the car.

7. Connect the negative - terminal of the battery.

• Be sure to turn the power off before changing the setting of any switch.

• If the fuse blows, check cables for shorts, then replace the fuse with one of the same rating.

• Check that no unconnected cables or connectors are touching the car body. Do not remove
caps from unconnected cables or connectors to prevent short circuits.

• Connect the speaker cables to appropriate speaker connectors separately. Sharing the negative
cable of the speaker or grounding speaker cables 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.

2CAUTION

4

English

Controls

Operations of the following control and switches are required in accordance with the center
unit and speakers connected with this unit.

GND

LINE IN

MAX 30 200

0.3

0.5 50

170

120

1.0

90

MIN

INPUT SENSITIVITY(V) BASS

ENPHASIS

POWER IN

GND

FUSE(25A)

BATT P.CON(REMOTE)

OFF ON

LEFT

LOWPASS FILTER

FREQUENCY(Hz)

L

R

RIGHT

SPEAKER LEVEL INPUT

25

MONO POWER AMPLIFIER

MONO

SPEAKER OUTPUT

!

214 7 8 9 05 63

1

RCA cable ground lead terminal

2

LINE IN terminal

3

INPUT SENSITIVITY control

Set this control according to the pre-output level of the center unit
connected with this unit, or to the maximum power output of the genuine­accessory car stereo.
Use the diagram on the right as a guide.

For the pre-output level or the maximum power output, refer to the
“Specifications” in the instruction manual of the center unit.

4

LOW PASS FILTER FREQUENCY control

This control adiusts the frequency band output from this unit.

5

BASS EMPHASIS switch

This switch allows to emphasize the output from this unit.

6

Speaker level input terminals

7

Battery terminal

8

Ground terminal

9

Power control (REMOTE) terminal

0

FUSE (25 A ×1)

!

Speaker output terminals

NOTE

0.3

0.2

0.5

1

2

3

4

5

(V)

(W)

25

15

10

English

5

Protection function

This unit is equipped with a protection function for protecting this unit and your speakers
from various accidents or problems that can occur.
When the protection function is triggered, the Power indicator goes off and the amplifier
stops operating.

■

Power indicator:

When the power is turned on, the Power indicator lights.
If the Power indicator does not light when the power is turned on, the protection function
may be activated. Check whether there is any indication of trouble.

■

The protection function activates in the following situations:

• When a speaker cable may be short-circuited.

• When a speaker output contacts ground.

• When the unit malfunctions and a DC signal is sent to the speaker output.

• When the temperature of internal parts exceeds 120°C (248°F).

• When a ground cable of the center unit (cassette receiver, CD receiver, etc.) or this unit is
not connected to a metal part serving as an electrical ground passing electricity to the
battery's negative - terminal.

MONO POWER AMPLIFIER

MONO

SPEAKER OUTPUT

Power indicator

Connection

■

Speakers cable connection

MONO POWER AMPLIFIER

MONO

SPEAKER OUTPUT

MONO

SPEAKER O

U

TPU

T

Lead terminal
(Commercially available parts)

Subwoofer

■

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.

• Use speakers that have an impedance of 2Ω or greater. 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.

240W
(4Ω)

4 Ω

240W
(4Ω)

240W
(4Ω)

240W
(4Ω)

8 Ω

2 Ω

120W
(4Ω)

240W
(4Ω)

240W
(4Ω)

120W
(4Ω)

(120W/8Ω) (420W/2Ω)

Maximum output of
the amplifier

Combined
impedance

Rated input power and
impedance of the speakers

• The genuine-accessory car stereo shall have a maximum power output of no more than 25 W.

• Do not connect the speaker output leads from a power amplifier (Optional) to the speaker input
terminals of this unit, for this may cause malfunction or damage.

• Do not connect cables and leads to both RCA cable input jacks and the speaker input terminals
simultaneously, for this may cause malfunction or damage.

• Connect the power control lead to a power supply which can be turned ON/OFF by the ignition
key switch (ACC line).
With this connection, shock noise may be generated when the power of the genuine-accessory
car stereo is switched ON/OFF.

2CAUTION

6

English

Connection

GND

LINE IN

MAX 30 200

0.3

0.5 50

170

120

1.0

90

MIN

INPUT SENSITIVITY(V) BASS

ENPHASIS

POWER IN

GND

FUSE(25A)

BATT P.CON(REMOTE)

OFF ON

LEFT

LOWPASS FILTER
FREQUENCY(Hz)

L

R

RIGHT

SPEAKER LEVEL INPUT

25

- +

GND

LINE IN

MAX 30 200

0.3

0.5 50

170

120

1.0

90

MIN

INPUT SENSITIVITY(V) BASS

ENPHASIS

POWER IN

GND

FUSE(25A)

BATT P.CON(REMOTE)

OFF ON

LEFT

LOWPASS FILTER

FREQUENCY(Hz)

L

R

RIGHT

SPEAKER LEVEL INPUT

25

■

RCA cable connection

CENTER UNIT

(Cassette receiver,

CD receiver, etc.)

Power control cable
(Commercially
available part)

RCA cable
(Commercially
available part)

Do not connect cables and leads
to both RCA cable input jacks
and the speaker input terminals
simultaneously, for this may
cause malfunction or damage.

2CAUTION

G

N

D

RCA cable ground terminal

When using an RCA cable with
a ground lead attached, connect
the ground lead to this terminal.

Do not use this terminal for power source
grounding. This unit will be damaged if the
power source grounding wire is connected
to this terminal.

2CAUTION

Genuine-accessory

car stereo

■

Speaker level input connection

ACC

Battey

Left output (White)

Right output (Red)

Left input

Right input

Left input

Right input

Left output

Right output

Lead terminal
(Commercially
available parts)

Speaker level input terminals

Car fuse
box

English

7

GND

LINE IN

MAX 30 200

0.3

0.5 50

170

120

1.0

90

MIN

INPUT SENSITIVITY(V) BASS

ENPHASIS

POWER IN

GND

FUSE(25A)

BATT P.CON(REMOTE)

OFF ON

LEFT

LOWPASS FILTER

FREQUENCY(Hz)

L

R

RIGHT

SPEAKER LEVEL INPUT

25

Terminal cover

Battery

Ground cable
(Commercially available part)

Battery cable
(Commercially available part)

Power control cable
(Commercially available part)

Round terminal (Large)

■

Power wire connection

To prevent fire caused by a short in the wiring, connect a fusible link or breaker nearby the battery’s
positive terminal.

Wiring

• 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 cord 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 attach a protective fuse into the battery wire close to the battery. Use a protective fuse
having a capacity that is about 10 A higher than the maximum current drawn by the amplifier.

• Use vehicle-type (fire-resistant) power supply wiring wire for the battery wire and the ground wire.
The current capacity of the power supply wiring wire should be about 10 A higher than that of the
protective fuse capacity (which means about 20 A higher than the maximum current drawn by the
amplifier).

• 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.

Power terminal

Connect to their respective terminals the power control wire, power supply wire, and ground
wire, all of which pass through the associated terminal cover. Once the connections are
complete, place the cover on the terminal section.

2WARNING

Maximum Current Drawn

Protective Fuse

Cross-sectional Area of Wiring

Wire (AWG)

15 A

30 A × 1 [15 A × 2]

3 mm2(AWG 12) or

greater × 1

Example: One Power Amplifier Is Used

30 A

15 A 15 A

15 A

15 A

Power terminal

Protective
Fuse

Round terminal (Small)

Round terminal (Medium)

8

English

Specifications

Specifications subject to change without notice.

Audio Section

Max Power Output (4 Ω) ..............................................................................240 W × 1 (at 100 Hz)

Rated Power Output (4 Ω) ........................................120 W × 1 (DIN45324, +B=14.4V, at 100 Hz)

Rated Power Output (2 Ω) ........................................................160 W × 1 (0.8 % THD at 100 Hz)

Signal to Noise Ratio............................................................................................................100 dB

Sensitivity (MAX) ..........................................................................................0.15 V (rated output)

Sensitivity (MIN) ..............................................................................................4.0 V (rated output)

Input Impedance....................................................................................................................10 kΩ

Damping Factor........................................................................................................More than 100

Low Pass Filter Frequency (12 dB / oct.) ....................................................30 ~ 200 Hz (Variable)

General

Operating Voltage................................................................................14.4 V (11 ~ 16 V allowable)

Current Consumption (1 kHz, 10% THD, 4 Ω) ........................................................................15 A

Dimensions (W × H × D)..................................................................................290 × 56 × 170 mm

Weight ..................................................................................................................................3.0 kg

Troubleshooting Guide

What might appear to be a malfunction in your unit may just be the result of slight
misoperation or miswiring. Before calling service, first check the following table for possible
problems.

PROBLEM POSSIBLE CAUSE SOLUTION

No sound.
(No sound from one side.)

The output level is too
small (or too large).

The sound quality is bad.
(The sound is distorted.)

• Input (or output) cables are
disconnected.

• Protection circuit may be
activated.

• The fuse may be blown
because the volume was too
high.

The input sensitivity adjusting
control is not set to the correct
position.

• The speakers cable are
connected with wrong + / -
polarity.

• A speaker cable is pinched by a
screw in the car body.

• The switches may be set
improperly.

• Connect the input (or output)
cables.

• Check connections by referring
to "Protection function".

• Replace the fuse with a new
fuse and use a lower volume.

Adjust the control correctly
referring to “Controls”.

• Connect them properly checking
the + / - of the terminals and
cables well.

• Connect the speaker cable again
so that it is not pinched by
anything.

• Set switches properly by

referring to "Controls".