Kenwood KAC 9104D Manual

The Kenwood KAC 9104D is a high-performance 4-channel car amplifier designed to deliver exceptional audio quality with 1000W max power output. Features include MOSFET power supply, variable high-pass/low-pass filters, bass boost, speaker-level inputs, and protection circuits. Below are key sections for installation, specifications, controls, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Devices 7. Operation 8. Protection Features 9. Care & Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: MOSFET power supply, variable electronic crossover, bass boost control, speaker-level inputs, thermal/overload/short circuit protection.

Feature	Description
Power Output	1000W Max Power (4 x 90W RMS at 4Ω)
MOSFET Power Supply	Efficient and reliable power delivery
Variable Crossover	High-pass/low-pass filters (50-200Hz)
Bass Boost	0-12dB boost at 50Hz
Speaker-Level Inputs	Connect directly to factory head units
Protection Circuits	Thermal, overload, and short circuit protection
RCA Inputs	For aftermarket head unit connection
Remote Turn-on	Remote wire for automatic power on/off
Fuse Rating	25A x 2
Dimensions	11-13/16" W x 2-3/8" H x 9-1/2" D

Installation

Choose proper mounting location and ensure adequate ventilation.

Disconnect negative battery terminal before installation.
Mount amplifier securely using provided hardware.
Connect power wire (12V) with appropriate fuse near battery.
Connect ground wire to clean, bare metal chassis point.
Connect remote turn-on wire to head unit remote output.
Connect RCA cables from head unit to amplifier inputs.
Connect speaker wires to appropriate channels.

WARNING! Ensure proper fuse rating and secure all connections to prevent electrical hazards.

First-Time Setup

Configure amplifier settings after installation.

Set input level: Adjust gain control to match head unit output.
Configure crossover: Set high-pass/low-pass filters based on speaker setup.
Adjust bass boost: Set to desired level (0-12dB at 50Hz).
Test all channels: Verify proper operation of all connected speakers.
Fine-tune settings: Make final adjustments for optimal sound quality.

CAUTION! Start with low gain settings and gradually increase to prevent speaker damage.

Specifications

Max Power Output: 1000W
RMS Power: 4 x 90W at 4Ω, 4 x 150W at 2Ω
Frequency Response: 10Hz - 50kHz
Signal-to-Noise Ratio: 100dB
Crossover Frequency: 50-200Hz (high-pass/low-pass)
Bass Boost: 0-12dB at 50Hz
Input Sensitivity: 200mV - 4V
Fuse Rating: 25A x 2
Operating Voltage: 14.4V DC (11-16V allowable)
Dimensions: 300mm x 60mm x 241mm (W x H x D)

Controls and Settings

Front panel controls: Power indicator, protection indicator. Top panel controls: Gain, bass boost, crossover frequency, crossover mode.

Control Functions:

Gain Control: Adjusts input sensitivity (200mV-4V). Bass Boost: 0-12dB boost at 50Hz. Crossover Frequency: 50-200Hz adjustment. Crossover Mode: High-pass, low-pass, or full range. Input Selector: RCA or speaker-level input selection.

Connecting Devices

Power Connections: 12V power, ground, remote turn-on. Audio Inputs: RCA inputs or speaker-level inputs. Speaker Outputs: 4-channel speaker connections.

Disconnect battery before making connections.
Use appropriate gauge wire for power and ground.
Route audio cables away from power wires to prevent noise.
Ensure secure connections at all terminals.
Connect speakers with proper polarity.

Tip: Use crimp connectors or solder connections for reliability.

Operation

Normal operation procedures and settings adjustment.

Power on: Amplifier turns on automatically with head unit.
Volume adjustment: Use head unit volume control primarily.
Gain adjustment: Set to match head unit output level.
Crossover settings: Adjust based on speaker capabilities.
Bass boost: Use sparingly to avoid distortion.
Monitoring: Check amplifier temperature during extended use.

WARNING! Do not operate with cover removed. Ensure adequate ventilation.

Protection Features

Thermal Protection: Automatically shuts down if temperature exceeds safe limits. Overload Protection: Protects against excessive current draw. Short Circuit Protection: Prevents damage from speaker wire shorts. DC Offset Protection: Shuts down if DC voltage detected at outputs.

Care & Maintenance

Keep amplifier clean and free of dust. Ensure proper ventilation. Check connections periodically for corrosion or looseness.

CAUTION! Do not use chemical cleaners. Disconnect power before cleaning.

Regulatory Information

FCC Part 15: Class B digital device compliance. CE marked for European compliance. Manufactured to meet international safety standards. Copyright © Kenwood Corporation. For support, visit www.kenwood.com or contact authorized service centers.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Power/ground connections	Check 12V and ground connections; verify fuse condition.
Protection mode active	Overheating/short circuit	Allow to cool; check speaker wires for shorts.
No sound	Input connections/settings	Check RCA/speaker-level inputs; verify gain settings.
Distorted sound	Gain too high/clipping	Reduce gain setting; check head unit output level.
Overheating	Insufficient ventilation	Improve airflow; check impedance load.

Reset: Disconnect power for 30 seconds to reset protection circuits.

Service: Contact authorized Kenwood service center for repairs.