Kenwood KAC-848 & KAC-748 4-Channel Power Amplifier
Instruction Manual
Safety Precautions
WARNING
To prevent injury or fire, take the following precautions:
- When extending ignition, battery, or ground wires, use automotive-grade wires with 5mm² (AWG10) or more to prevent wire deterioration and damage to the wire coating.
- Never put or leave metallic objects (such as coins or metal tools) inside the unit to prevent short circuits.
- If the unit emits smoke or strange smells, turn off power immediately and consult your Kenwood dealer.
- Do not touch the unit during use as it becomes hot and may cause burns.
CAUTION
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 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, use only 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.
NOTE
- 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.
FCC WARNING
This equipment may generate or use radio frequency energy. Changes or modifications to this equipment may cause harmful interference unless the modifications are expressly approved in the instruction manual. The user could lose the authority to operate this equipment if an unauthorized change or modification is made.
Accessories
| Part name | External View | Number of Items |
|---|---|---|
| Terminal cover (Power terminal) | [Description of terminal cover] | 1 |
| Self-tapping screws (ø4 x 16 mm) | [Description of screws] | 4 |
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 wire may be short-circuited.
- When a speaker output contacts ground.
- When the temperature of internal parts exceeds 120°C (248°F).
- 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.
Installation Procedure
- Remove the ignition key and disconnect the negative terminal of the battery to prevent short circuits.
- Set the unit according to the intended usage.
- Connect the input and output cables of the units.
- Connect the speaker wires.
- Connect the power wire, power control wire and grounding wire following this order.
- Install the unit in the car.
- Connect the negative terminal of the battery.
CAUTION:
- 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.
Installation
Description of mounting the unit using self-tapping screws on an installation board (15 mm or more thick).
Extension cables (Optional)
| Type | 0.5m | 1m | 2m | 4m | 5m | 6m |
|---|---|---|---|---|---|---|
| RCA cable | CA-2SL | CA-12SL | CA-22SL | CA-52SL | ||
| RCA cable (ø7mm) | CA-3WL | CA-13WL | CA-23WL | CA-53WL | ||
| RCA cable (ø12mm) | CA-5W | CA-15W | CA-25W | CA-45W | CA-65W |
CAUTION:
- 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.
Controls
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.
KAC-848 & KAC-748 Unit Layouts
Description of the KAC-848 unit layout, showing terminals 1 through 6.
Description of the KAC-748 unit layout, showing terminals 1 through 9.
Terminal Descriptions:
- Fuse (20 A x 2 for KAC-848; 30 A x 1 for KAC-748)
- Battery terminal
- Ground terminal
- Power control (REMOTE) terminal
- Amplifier A speaker output terminals
- Amplifier B speaker output terminals
Amplifier A & B Controls
Description of Amplifier A and Amplifier B control panels, showing various knobs and switches.
Control Descriptions:
- Fuse (20 A x 2 : KAC-848) / (30 A x 1 : KAC-748)
- Battery terminal
- Ground terminal
- Power control (REMOTE) terminal
- Amplifier A speaker output terminals
- Amplifier B speaker output terminals
- Speaker level input terminals (KAC-748 only)
- FREQUENCY control
- FILTER switch
- OPERATION switch
- INPUT SENSITIVITY control (with diagram showing range 0.3V to 4.0V)
- RCA cable ground lead terminal
- INPUT SELECTOR switch
- Amplifier A LINE IN terminal
- Amplifier B LINE IN terminal
- LINE OUT terminal
Detailed Control Explanations:
- SPEAKER OUTPUT terminals:
- Stereo Connections: For stereo amplification. Speakers should have impedance of 2Ω or greater. Combined impedance must be 2Ω or greater per channel.
- Bridged Connections: For high-output monaural amplification. Connect to LEFT (+) and RIGHT (-) SPEAKER OUTPUT terminals. Speakers should have impedance of 4Ω or greater. Combined impedance must be 4Ω or greater.
- CAUTION: The rated input of the speakers should be no less than the maximum output of the amplifier. Otherwise malfunction may result.
- Speaker level input terminals (KAC-748 only): Connect the unit by inserting it in the connection between the genuine-accessory car stereo and speakers.
- 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.
- FILTER switch: High-pass or low-pass filtering can be applied to the speaker output according to the setting of this switch.
- 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.
- STEREO position: The amplifier can be used as a stereo amplifier.
- L+R position: The input left and right signals are combined before being amplified. Use this position when the unit is used for subwoofer speakers or the L+R (monaural) sound is required.
- 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.)
- 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. Use the diagram on the right as a guide.
- RCA cable ground lead terminal: When using an RCA cable with a ground lead attached, connect the ground lead to this terminal. CAUTION: 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.
- 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.
- Amplifier A LINE IN terminal
- Amplifier B 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.
Connection
RCA cable connection
CAUTION: 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.
Description of RCA cable connection diagram: Shows RCA cables connecting from the CENTER UNIT's front/rear outputs to the Amplifier's A/B LINE IN terminals. Also shows connection from LINE OUT to other units. Includes RCA cable ground terminal connection.
CAUTION: Do not use the RCA cable ground terminal for power source grounding. This unit will be damaged if the power source grounding wire is connected to this terminal.
Speaker level input connection (KAC-748 only)
Description of speaker level input connection diagram: Shows connection from the genuine-accessory car stereo's speaker outputs (Front Left/Right, Rear Left/Right) to the Amplifier's A/B SPEAKER LEVEL INPUT terminals.
Speakers wire connection
Stereo Connections
Description of stereo speaker wire connection diagram: Shows Front Left, Front Right, Rear Left, and Rear Right speakers connected to the respective speaker output terminals (A Left, A Right, B Left, B Right) on the amplifier.
Bridged Connections
Description of bridged speaker wire connection diagram: Shows speakers connected to the bridged output terminals (A Bridged, B Bridged) on the amplifier.
CAUTION:
- 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.
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.
Examples:
| Model | Stereo Connections (4Ω) | Bridged Connections (4Ω) |
|---|---|---|
| KAC-848 | 100 W or greater | 300 W or greater |
| KAC-748 | 70 W or greater | 200 W or greater |
Diagrams illustrating maximum output, combined impedance, and rated input/impedance of speakers for stereo and bridged configurations.
Power wire connection
WARNING: 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.
Example: One Power Amplifier Is Used
| Model | Maximum Current Drawn | Protective Fuse | Cross-sectional Area of Wiring (AWG) |
|---|---|---|---|
| KAC-848 | 38 A | 50 A x 1 [25 A x 2] | 5 mm² (AWG 10) or greater x 1 |
| KAC-748 | 28 A | 40 A x 1 [20 A x 2] | 5 mm² (AWG 10) or greater x 1 |
Diagrams showing fuse examples (50A, 25A).
System Examples
Full-range 4-channel + Subwoofer system
Description of the system diagram: Shows a CENTER UNIT connected via RCA cables to an AMPLIFIER (KAC-848/KAC-748). The amplifier is connected to a Front Speaker, Rear Speaker, and Subwoofer. Switch settings for the amplifier are indicated.
Troubleshooting Guide
| PROBLEM | POSSIBLE CAUSE | SOLUTION |
|---|---|---|
| No sound. (No sound from one side.) |
|
|
| The output level is too small (or too large). | The input sensitivity adjusting control is not set to the correct position. | Adjust the control correctly referring to "Controls". |
| The sound quality is bad. (The sound is distorted.) |
|
|
Specifications
Audio Section
| KAC-848 | KAC-748 | |
|---|---|---|
| Max Power Output (4 Ω) | ||
| 4 Channel Mode | 100 W x 4 | 70 W x 4 |
| 3 Channel Mode | 100 W x 2 + 300 W x 1 | 70 W x 2 + 200 W x 1 |
| 2 Channel Mode | 300 W x 2 | 200 W x 2 |
| Rated Power Output (4 Ω) | ||
| 4 Channel Mode (20 Hz ~ 20 kHz, less than 0.08% THD) | 50 W x 4 | 35 W x 4 |
| 3 Channel Mode (1 kHz, 0.08% THD) + (1 kHz, 0.8% THD) | 50 W x 2 + 150 W x 1 | 35 W x 2 + 100 W x 1 |
| 2 Channel Mode (1 kHz, 0.8% THD) | 150 W x 2 | 100 W x 2 |
| Rated Power Output (2 Ω) | ||
| 4 Channel Mode (1 kHz, 0.8% THD) | 75 W x 4 | 50 W x 4 |
| Frequency Response (+0, -1 dB) | 5 Hz ~ 50 kHz | 5 Hz ~ 50 kHz |
| Signal to Noise Ratio | 100 dB | 100 dB |
| Sensitivity (MAX) (rated output) | 0.15 V | 0.15 V |
| (MIN) (rated output) | 4.0 V | 4.0 V |
| Input Impedance | 10 kΩ | 10 kΩ |
| Low Pass Filter Frequency (12 dB/oct.) (Variable) | 50 ~ 200 Hz | 50 ~ 200 Hz |
| High Pass Filter Frequency (12 dB/oct.) (Variable) | 50 ~ 200 Hz | 50 ~ 200 Hz |
General
| KAC-848 | KAC-748 | |
|---|---|---|
| Operating Voltage (11 ~ 16 V allowable) | 14.4 V | 14.4 V |
| Current Consumption (1 kHz, 10% THD) | 38 A | 28 A |
| Dimensions (W x H x D) | 290 x 56 x 280 mm (11-7/16×2-3/16×11 in.) | 290 x 56 x 230 mm (11-7/16×2-3/16×9-1/16 in.) |
| Weight | 4.3 kg (9.4 lb) | 3.7 kg (8.1 lb) |
Warranty Information
Kenwood Limited Warranty for Car Stereo Components (U.S.A.)
This warranty will be honored only in the U.S.A.
Kenwood U.S.A. Corporation ("Kenwood") warrants this product for a period of one (1) year from the date of original purchase.
What is Covered and What is Not Covered
Except as specified below, this warranty covers all defects in material and workmanship in Kenwood car stereo components. The following are not covered by the warranty:
- Any product which is not distributed in the U.S.A. by Kenwood or which is not purchased in the U.S.A. from an authorized Kenwood car stereo dealer or an automobile dealer, unless the product is purchased through the U.S.A. Military Exchange Service.
- Any product on which the serial number has been defaced, modified or removed.
- Damage, deterioration or malfunction resulting from:
- Any shipment of the product (claims must be presented to the carrier).
- Installation or removal of the product.
- Accident, acts of nature, misuse, abuse, neglect, unauthorized product modification or failure to follow instructions supplied with the product.
- Repair or attempted repair by anyone not authorized by Kenwood.
- Any other cause which does not relate to a product defect.
Who is Protected
This warranty is enforceable only by the original purchaser.
What We Will Pay For
We will pay for all labor and material expenses for covered items. Payment of shipping charges is discussed in the next section of this warranty.
How to Obtain Warranty Service
- Take or ship it to any KENWOOD Authorized Service Center in the U.S.A. along with a complete description of the problem. (If you are uncertain as to whether a Service Center is authorized, please call 1-800-KENWOOD for the nearest Service Center. 1-800-536-9663).
- Although you must pay any shipping charges if it is necessary to ship the product for warranty service, we will pay the return shipping charges if the repairs are covered by the warranty within the United States.
- Whenever your units are taken or sent for warranty service, you must include a copy of the original dated sales receipt as proof of warranty coverage.
Limitation of Implied Warranties
All implied warranties, including warranties of MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, are limited in duration to the length of this warranty.
Exclusion of Damages
KENWOOD'S LIABILITY FOR ANY DEFECTIVE PRODUCT IS LIMITED TO THE REPAIR OR REPLACEMENT OF THE PRODUCT AT OUR OPTION. KENWOOD SHALL NOT BE LIABLE FOR:
- INSTALLATION OR REMOVAL CHARGES, DAMAGE TO OTHER PROPERTY CAUSED BY ANY DEFECTS IN KENWOOD CAR STEREO COMPONENTS, DAMAGES BASED UPON INCONVENIENCE, LOSS OF USE OF THE PRODUCT; OR
- ANY OTHER DAMAGES, WHETHER INCIDENTAL, CONSEQUENTIAL OR OTHERWISE.
Some states do not allow limitations on how long an implied warranty lasts and/or do not allow the exclusion or limitation of incidental or consequential damages, so the above limitations and exclusions may not apply to you.
This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
If a problem develops during or after the Limited Warranty Period, or if you have any questions regarding the operation of the product, you should contact your KENWOOD Authorized Dealer or Authorized Service Center. If the problem or your question is not handled to your satisfaction, please contact our Customer Relations Department at the address listed below:
KENWOOD SERVICE CORPORATION
P.O Box 22745, 2201 East Dominguez Street, Long Beach CA 90801-5745
Tel: (310) 639-5300
