KAC-8401(M) 1English

02.11.14

10:38 AM

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KAC-8401

4-CHANNEL POWER AMPLIFIER

INSTRUCTION MANUAL

B64-2575-00/00 (MV)

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Safety precautions

2WARNING

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.

2CAUTION

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 5 mm2 (AWG 10) 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.
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.

To prevent battery rise

When the unit is used in the ACC ON position without turning the engine ON, it depletes the battery. Use it after starting the engine.

Protection function

There is a Protection function installed in the unit to protect the unit and speakers from various problems. When Protection operates, the indicator informs you of the condition. (Refer to page 5)
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.

Accessories

Part name Self-tapping screws (mm) Terminal cover (Power terminal) Speaker level input cable External View Number of Items 1
If you experience problems during installation, consult your Kenwood dealer. If the unit does not seem to be working right, consult your Kenwood dealer.

English

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Installation

Cooling fan Self-tapping screw (mm)
Installation board, etc. (thickness : 15 mm or more)
2CAUTION Do not install in the below locations; (Unstable location, In a location that interferes with driving, In a location that gets wet, In a dusty location, In a place that gets hot, In a place that gets direct sunlight, In a location that gets hit by hot air) 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. This unit has cooling fans to decrease the internal temperature. Be careful not to block the cooling fan openings when installing the unit. Blocking these openings will inhibit the cooling of the internal temperature and result in malfunction. 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.

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Controls / Indicator

(W) 10

This is a 4 channel amplifier including 2 stereo amplifiers in a body. One amplifier is referred to as amplifier A and the other is amplifier B. This unit is compatible with a large variety of systems by combining the switches and functions described in the following.

3 FILTER switch

This switch allows to apply high-pass or low-pass filtering to the speaker outputs.
HPF (High-Pass Filter) position:
The filter outputs the band of higher frequencies than the frequency set with the FILTER FREQUENCY control.
1 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 genuine-accessory car stereo. The sensitivities of amplifiers A and B can be adjusted independently regardless of the position of the input selector switch. Use the diagram on the right as a guide.

OFF position:

The entire bandwidth is output without filtering.
LPF (Low-Pass Filter) position:
The filter outputs the band of lower frequencies than the frequency set with the FILTER FREQUENCY control.

4 OPERATION switch

The amplification methods of the signals input to amplifiers A and B can be selected independently according to the setting of this switch.
For the pre-output level or the maximum power output, refer to the Specifications in the instruction manual of the center unit.

STEREO position:

The amplifier can be used as a stereo amplifier.

2 Bch BASS BOOST switch

Setting this switch to "ON" emphasizes the bass. You can use the BASS BOOST for amplifier B only.

MONO (Lch) position:

Amplifies the signal input from the left side only. Set to this position and make bridged connections to use as a high-power monaural amplifier. (The input right signal is not output.)

ON position:

BASS BOOST is +6 dB.

BASS BOOST is OFF.

5 INPUT SELECTOR switch
This switch selects the input method of the signals to be amplified by amplifiers A and B.

A B position:

Amplifies both of the signals input to amplifiers A and B.

A position:

Amplifies only signal input amplifier A with both amplifiers A and B.

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6 FILTER FREQUENCY control
When the FILTER switch is set to the HPF (High-Pass Filter) or LPF (Low-Pass Filter) position, the threshold frequency can be adjusted with this control.
The protection function is activated in the following situations:

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. When a speaker wire may be shortcircuited. When a speaker output contacts ground. When the unit malfunctions and a DC signal is sent to the speaker output. When the internal temperature is high and unit wont operate. When a ground wire 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.

7 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.

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Connection

Terminal names

8 Fuse (40 A)
amplifier. Otherwise malfunction may result.
If you cant find the specified capacity fuse at your store etc., consult your Kenwood dealer.
# RCA cable ground lead terminal
When using an RCA cable with a ground lead attached, connect the ground lead to this terminal.
9 Battery terminal 0 Ground terminal ! Power control terminal
Controls the unit ON/OFF.
$ LINE IN terminal % LINE OUT terminal
These jacks output respectively the signals input to amplifiers A and B. They always output the stereo signals regardless of the position of the OPERATION switch.
Controls the unit power. Be sure to connect it with all the systems.
@ Speaker output terminals Stereo Connections:
When you wish to use the unit as a stereo amplifier, stereo connections are used. The speakers to be connected should have an impedance of 2 or greater. When multiple speakers are to be connected, ensure that the combined impedance is 2 or greater for each channel.
^ Speaker level input terminals

Bridged Connections:

When you wish to use the unit as a highoutput monaural amplifier, bridged connections are used. (Make connections to the LEFT channel 9 and the RIGHT channel SPEAKER OUTPUT terminals.) The speakers to be connected should have an impedance of 4 or greater. When multiple speakers are to be connected, ensure that the combined impedance is 4 or greater.

The genuine-accessory car stereo shall have a maximum power output of no more than 40 W. Do not connect the speaker output leads from a power amplifier (Optional) to the speaker level 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 level 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.
The rated input of the speakers should be no less than the maximum output of the

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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.

Wiring

Take the battery wire for this unit directly from the battery. If it's connected to the vehicles 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 batterys 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 units 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 units fuse capacity. (Use a power wiring cord with a diameter of 5 mm2 (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 currenthandling capacity than the total maximum current drawn by each amplifier.
To prevent fire caused by a short in the wiring, connect a fusible link or breaker nearby the batterys 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.

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 2 or greater (for stereo connections), or 4 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.

Combined impedance

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RCA cable or Speaker level input connection (RCA cable Connections)
RCA cable ground terminal

RCA cable*

CENTER UNIT (CD receiver, etc.)
A channel Left input A channel Right input
B channel Left input B channel Right input
Power control wire (Blue/ White)
(Speaker level input Connections)
Cable Color of the connector White A channel Left White/Black Gray A channel Right Gray/Black Green B channel Left Green/Black Purple B channel Right Purple/Black
Genuine-accessory car stereo (No line output center unit etc.)

Car fuse box ^

Battery ACC

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* Commercially available parts
Speaker wire connection (Stereo Connections)
@ Lead terminal* @ A channel Left speaker A channel Right speaker

(Bridged Connections)

Power wire connection
B channel Right speaker B channel Left speaker
A channel Speaker (Bridged)
B channel Speaker (Bridged)

9 Terminal cover

0 ! Lead terminal*
Extension wire* Battery wire*

Ground wire*

Protective Fuse* Battery

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System examples

4-channel system (1)

L A R L B R

L R L R

Front Left speaker Front Right speaker Rear Left speaker Rear Right speaker 3

CENTER UNIT

3-channel system (1)
Left speaker (High pass) Right speaker (High pass) Subwoofer (L + R) (Bridged) 3

2-channel system

Left speaker (Bridged)
Right speaker (Bridged) 3

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Tri-mode

(High pass)

Subwoofer (L + R) (Bridged)
Principle of Tri-mode Method of frequency band division using a coil and capacitorin case of 6dB/oct. slope Crossover Frequency 0 dB -3 dB
Coil (L): Passes low frequencies and blocks high frequencies. (Low pass) Capacitor (C): Passes high frequencies and blocks low frequencies. (High pass) 159000 (F) fc x R 159 x R L= (mH) fc C= fc=Cut of Frequency (Hz) R=Speaker Impedance ()

Frequency

Example: When it is required to set a crossover frequency of 120 Hz using speakers with an impedance of 4 ohms. Prepare commercially-available coil and capacitor with the closest ratings to the results calculated from the formula above. The capacitor rating should be as close as possible to 331.25 (F) and the coil rating should be as close as possible to 5.3 (mH).
If you wish to bridge-connect a speaker, the speaker impedance must be no less than 4 ohms. Connecting a speaker with an impedance lower than 4 ohms may damage the unit. Be sure to connect capacitors to speakers to which high frequencies will be passed. Failure to do so will result in a drop of the combined impedance with the subwoofer. Ensure that the withstand voltage and current ratings of the capacitors (C) and coils (L) are sufficient.

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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

No sound. (No sound from one side.) (Blown fuse.)

POSSIBLE CAUSE

Input (or output) cables are disconnected. Protection circuit may be activated. Volume is too high. The speaker cord is shorted.

SOLUTION

Connect the input (or output) cables. Check connections by referring to "Indicator". Replace the fuse and use lower volume. After check the speaker cord and fixing the cause of the short, replace the fuse. Adjust the control correctly referring to Controls. Connect them properly checking the + / - of the terminals and wires well. Connect the speaker wire again so that it is not pinched by anything. Set switches properly by referring to "System examples".
The output level is too small (or too large). The sound quality is bad. (The sound is distorted.)
The input sensitivity adjusting control is not set to the correct position. The speakers wire are connected with wrong + / polarity. A speaker wire is pinched by a screw in the car body. The switches may be set improperly.

Specifications

Specifications subject to change without notice. Audio Section

Max Power Output...320 W 2 Rated Power Output Normal (4 ) (20 Hz 20 kHz, 0.08 % THD)...60 W 4 Normal (2 ) (1 kHz, 0.8 % THD)...90 W 4 Bridged (4 ) (1 kHz, 0.8 % THD)...180 W 2 Frequency Response (+0, 3 dB)....5 Hz 50 kHz Sensitivity (rated output) (MAX.)...0.2 V Sensitivity (rated output) (MIN.)...5.0 V Signal to Noise Ratio....100 dB Input Impedance....10 k Low Pass Filter Frequency (12 dB/oct.)..Hz (variable) High Pass Filter Frequency (12 dB/oct.)..Hz (variable) Bass Boost Circuit (90 Hz)....OFF / +6 dB

General

Operating Voltage....14.4 V (V allowable) Current Consumption (4 , 10 % THD)...39 A Dimensions (W H D)...268 mm...11-1/4 2-1/4 10-9/16 inch Weight.....2.96 kg (6.5 lbs)