Kenwood KAC 6406 Manual

The Kenwood KAC 6406 is a 4-channel car amplifier delivering 60W RMS per channel at 4 ohms, with MOSFET power supply, variable high/low pass filters, bass boost, speaker-level inputs, and protection circuits. Designed for multi-speaker systems with bridgeable channels for subwoofer applications. Below are key sections for safety, features, installation, setup, operation, specifications, and troubleshooting.

Features at a Glance

Key components: 4-channel amplifier, MOSFET power supply, speaker-level inputs, variable crossovers, bass boost, protection circuits.

Feature	Description
Power Output	60W RMS x 4 channels at 4 ohms
MOSFET Power Supply	Efficient power conversion and thermal performance
High/Low Pass Filters	Variable frequency adjustment for precise sound control
Bass Boost	+12dB boost at 50Hz for enhanced low frequencies
Speaker-Level Inputs	Connect directly to factory head unit outputs
Bridge Mode	Combine channels for higher power output
Protection Circuits	Thermal, short-circuit, and DC offset protection
Remote Turn-On	Automatic power control via head unit
LED Power Indicator	Blue LED shows amplifier status
Variable Gain Control	Adjust input sensitivity for optimal matching

Installation

Select proper mounting location and prepare wiring connections.

1. Choose mounting location: Secure, dry area with adequate ventilation.
2. Power connections: Connect +12V to battery, ground to chassis, remote to head unit.
3. Speaker connections: Connect speaker wires to appropriate channels.
4. Input connections: Use RCA or speaker-level inputs from source unit.
5. Fuse installation: Install appropriate fuse near battery connection.

WARNING! Disconnect battery before installation. Ensure proper grounding to prevent electrical damage.

Wiring Connections

Proper wiring ensures optimal performance and safety.

1. Power wire: 8-gauge minimum, fused within 18 inches of battery.
2. Ground wire: Same gauge as power, secure to clean metal surface.
3. Remote turn-on: Connect to head unit's remote output or accessory wire.
4. RCA inputs: Use shielded cables from head unit preamp outputs.
5. Speaker outputs: Connect positive/negative terminals correctly.

CAUTION! Route power and signal cables separately to avoid noise interference.

Specifications

• Channels: 4
• RMS Power: 60W x 4 @ 4 ohms, 90W x 4 @ 2 ohms
• Bridged Power: 180W x 2 @ 4 ohms
• Frequency Response: 10Hz - 50kHz (+0, -1dB)
• Signal-to-Noise Ratio: >100dB
• THD: <0.08%
• Crossover: High/Low pass 50Hz - 200Hz
• Bass Boost: 0 to +12dB @ 50Hz
• Input Sensitivity: 200mV - 4V
• Fuse Rating: 25A x 2
• Operating Voltage: 14.4V DC (11-16V range)

Controls and Settings

Access controls on amplifier end panel for system optimization.

Front Panel: Power LED, protection indicator.

Control Panel: Input level/gain control, high pass filter, low pass filter, bass boost, input mode switch (RCA/speaker level).

Gain: Adjust to match head unit output. Crossovers: Set HPF for mids/highs, LPF for subs. Bass Boost: Enhance low frequencies. Input Mode: Select RCA or speaker-level input.

Operation Modes

Multiple configuration options for different audio setups.

1. 4-channel mode: Standard operation for front/rear speakers.
2. 3-channel mode: Two channels for fronts, bridged for subwoofer.
3. 2-channel mode: Both channels bridged for higher power.
4. Bi-amp mode: Use crossovers for component speaker systems.

Tip: Match amplifier settings to speaker specifications for best performance.

Bridge Mode Setup

Combine two channels for higher power output to subwoofers.

1. Set amplifier to bridge mode using mode switch.
2. Connect positive speaker wire to CH1 positive terminal.
3. Connect negative speaker wire to CH2 positive terminal.
4. Set crossover to low pass for subwoofer applications.
5. Adjust gain and bass boost as needed.

WARNING! Do not bridge channels to impedance lower than 4 ohms. Check speaker compatibility.

Protection Features

Multiple protection circuits prevent damage to amplifier and speakers.

Thermal Protection: Automatically reduces output if overheating detected. Short-Circuit Protection: Shuts down if speaker wires short. DC Offset Protection: Prevents DC voltage to speakers. Over-Voltage Protection: Guards against voltage spikes.

Maintenance

Keep amplifier clean and properly ventilated.

CAUTION! Do not block ventilation openings. Clean with dry cloth only; no liquids or chemicals.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits. Copyright © Kenwood Corporation. For support, visit www.kenwood.com or contact authorized service centers.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Wiring/fuse	Check power, ground, remote connections; inspect fuses.
Protection mode active	Overheating/short circuit	Allow cooling; check speaker wires for shorts.
Distorted sound	Gain settings/clipping	Reduce gain; check input levels; verify speaker impedance.
No sound from channels	Input connections	Verify RCA/speaker level inputs; check source unit settings.
Engine noise	Grounding issues	Improve ground connection; reroute signal cables.

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

Service: Contact authorized Kenwood service center for repairs.