Kenwood XR400 4 Manual

The Kenwood XR400 4 is a high-performance 4-channel car amplifier designed for automotive audio systems. Featuring MOSFET power supply, variable high/low pass filters, bass boost, speaker-level inputs, and comprehensive protection circuits. Below are key sections for safety, features, installation, setup, operation, specifications, and troubleshooting.

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

Features at a Glance

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

Feature	Description
MOSFET Power Supply	For efficient power conversion and reliability
Speaker-Level Inputs	For connection to factory head units
Variable High/Low Pass Filters	Adjustable crossover frequencies
Bass Boost	+12dB boost at 45Hz
Protection Circuits	Thermal, short-circuit, and DC offset protection
RCA Inputs	For standard line-level connections
Gain Controls	Adjustable input sensitivity
Bridgeable Design	Can be bridged for 2-channel operation
Power LED Indicator	Shows amplifier status
Protection LED	Indicates fault conditions

Installation

Unpack and inspect contents. Choose proper mounting location.

Disconnect vehicle battery: Remove negative terminal first.
Mount amplifier: Secure to solid surface with proper ventilation.
Connect power: Run power cable from battery with fuse holder.
Connect ground: Use short, thick cable to clean metal surface.
Connect RCA cables: Route away from power wires.
Connect speaker wires: Observe proper polarity.
Connect remote turn-on: Connect to head unit remote wire.

WARNING! Always disconnect battery before installation. Ensure proper fuse rating.

First-Time Setup

Reconnect battery; follow setup procedure.

Set gain controls: Start at minimum, adjust gradually.
Set crossover frequencies: Adjust based on speaker capabilities.
Set bass boost: Start at minimum, increase as needed.
Test operation: Check all channels for proper function.
Fine-tune settings: Adjust while playing music.

CAUTION! Do not operate without proper load. Avoid clipping distortion.

Specifications

Power Output: 50W x 4 channels at 4 ohms
Bridged Power: 150W x 2 channels at 4 ohms
Frequency Response: 10Hz - 50kHz
Signal-to-Noise Ratio: >95dB
Input Sensitivity: 200mV - 4V
Crossover Range: 50Hz - 500Hz
Bass Boost: +12dB at 45Hz
Power Supply: MOSFET PWM
Fuse Rating: 25A x 2
Operating Voltage: 14.4V DC (11-16V)

Controls and Settings

Access controls via front panel adjustments.

Front Panel: Power LED, Protection LED, Gain controls, Crossover switches, Bass boost.

Gain: Adjust input sensitivity (200mV-4V). Crossover: HPF/LPF/Full range selection. Bass Boost: +12dB at 45Hz. Input Mode: RCA/Speaker level selection. Bridge Mode: Channel 1+2 and 3+4 bridging.

Connecting Devices

RCA Inputs: Standard line-level connections. Speaker-Level Inputs: For factory head units.

Turn off vehicle and disconnect battery.
Connect RCA cables from head unit to amplifier.
Connect speaker wires observing polarity.
Connect power, ground, and remote wires.
Reconnect battery and test system.

Tip: Keep signal cables away from power wires to avoid noise.

Operation Modes

Supports stereo, bridged, and multi-channel operation.

Stereo Mode: Standard 4-channel operation.
Bridged Mode: Combine channels for higher power.
Tri-mode: Front stereo + bridged rear for subwoofer.
Crossover Settings: HPF for speakers, LPF for subwoofers.
Input Selection: RCA or speaker-level inputs.

WARNING! Do not ground speaker outputs. Use proper impedance loads.

Protection Features

Thermal Protection: Shuts down if overheated. Short-Circuit Protection: Protects output stages. DC Offset Protection: Prevents DC damage to speakers. Over-current Protection: Limits current draw.

Care & Maintenance

Keep amplifier clean and dry. Ensure proper ventilation. Check connections periodically.

CAUTION! Do not block ventilation openings. Avoid moisture exposure.

Regulatory Information

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Power/ground connections	Check power, ground, and remote connections; verify fuse.
Protection mode active	Short circuit/overheating	Check speaker wires for shorts; allow cooling.
No sound	Input/settings	Check RCA connections; verify gain settings; test head unit.
Distorted sound	Gain/clipping	Reduce gain settings; check input levels.
Engine noise	Grounding issues	Improve ground connection; reroute RCA cables.

Reset: Disconnect power for 30 seconds to reset protection.

Service: Contact authorized Kenwood service center.