Kenwood KAC 6104D Manual

The Kenwood KAC 6104D is a 4-channel car amplifier delivering 50 watts RMS x 4 at 4 ohms or 75 watts RMS x 4 at 2 ohms. Features include MOSFET power supply, variable high-pass/low-pass filters, bass boost, speaker-level inputs, preamp outputs, and thermal/overload/short circuit protection. Below are key sections for installation, features, specifications, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. Wiring Connections 4. Specifications 5. Controls and Settings 6. Input Connections 7. Crossover Setup 8. Protection Features 9. Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: MOSFET power supply, variable electronic crossover, bass boost, speaker-level inputs, preamp outputs, protection circuitry.

Feature	Description
MOSFET power supply	Efficient and reliable power delivery
Variable crossover	High-pass and low-pass filter adjustment
Bass Boost	+12dB boost at 50Hz
Speaker-level inputs	Connect directly to factory head unit
Preamp outputs	Daisy-chain multiple amplifiers
Protection circuitry	Thermal, overload, and short circuit protection
Power LED	Blue illumination when powered on
Protection LED	Red indicator when protection mode active
Gain control	Adjust input sensitivity
Crossover frequency	50Hz - 200Hz adjustable

Installation

Choose proper mounting location and prepare wiring.

Select mounting location: Dry, well-ventilated area away from heat sources.
Mount amplifier: Use provided screws, ensure secure mounting.
Connect power: +12V to battery, ground to chassis, remote turn-on to head unit.
Connect speakers: Match impedance requirements (2-8 ohms).
Connect input: Use RCA or speaker-level inputs.

WARNING! Disconnect negative battery terminal before installation. Ensure proper fuse rating.

Wiring Connections

Proper wiring is essential for optimal performance and safety.

Power wire: 8-gauge minimum, fused within 18 inches of battery.
Ground wire: Same gauge as power, secure to bare metal chassis.
Remote turn-on: Connect to head unit's remote output or accessory wire.
Speaker wires: 16-gauge or larger, observe polarity.
RCA cables: Route away from power wires to avoid noise.

CAUTION! Use correct wire gauge; inadequate wiring can cause fire hazard.

Specifications

RMS Power: 50W x 4 @ 4Ω, 75W x 4 @ 2Ω
Peak Power: 150W x 4
THD: 0.08%
Frequency Response: 10Hz - 50kHz
Signal-to-Noise: 100dB
Crossover: High-pass/Low-pass 50-200Hz
Bass Boost: 0 to +12dB @ 50Hz
Input Sensitivity: 200mV - 4V
Fuse Rating: 25A x 2
Dimensions: 9-13/16" W x 2-3/16" H x 7-7/8" D

Controls and Settings

Access controls on amplifier end panel for system optimization.

Input Section: Input level control, input mode switch (RCA/Speaker level).

Crossover: HPF/LPF/FLAT position switch, frequency control 50-200Hz. Bass: Boost level control 0-12dB. Output: Preamp outputs for daisy-chaining.

Input Connections

Two input methods available: RCA or speaker-level.

RCA input: Connect to head unit preamp outputs for best quality.
Speaker-level input: Use when head unit lacks RCA outputs.
Input level: Adjust gain to match head unit output.
Input mode: Select RCA or Speaker level via switch.

Tip: Set gain properly to avoid distortion and noise.

Crossover Setup

Configure crossover for optimal speaker performance.

Select mode: HPF for speakers, LPF for subwoofers, FLAT for full range.
Set frequency: Rotate control for desired cutoff (50-200Hz).
Bass boost: Adjust if needed for low-frequency enhancement.
Test settings: Play music and adjust while listening.

WARNING! Incorrect crossover settings can damage speakers.

Protection Features

Multiple protection circuits safeguard the amplifier.

Thermal Protection: Automatically shuts down if temperature exceeds safe limits. Overload Protection: Activates during excessive current draw. Short Circuit Protection: Protects against speaker wire shorts. DC Offset Protection: Prevents DC voltage to speakers.

Maintenance

Keep amplifier clean and properly ventilated.

CAUTION! Do not block ventilation slots. Clean with dry cloth only; no liquids.

Regulatory Information

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Wiring/fuse	Check power, ground, remote connections; inspect fuses.
Protection mode	Overheating/short	Allow to cool; check speaker wires for shorts.
Distorted sound	Gain setting	Adjust input level; check head unit volume.
No sound	Input connections	Verify RCA/speaker level inputs; check mode switch.
Engine noise	Grounding	Improve ground connection; reroute RCA cables.

Reset: Disconnect power for 30 seconds to reset protection.

Service: Contact authorized Kenwood service center for repairs.