Kenwood MOSFET 50Wx4 Owner's Manual

The Kenwood MOSFET 50Wx4 is a high-performance car audio amplifier featuring MOSFET power supply technology, 50 watts RMS x 4 channels at 4 ohms, high-current output, low-level RCA inputs, speaker-level inputs, variable high-pass/low-pass crossovers, bass boost, and remote turn-on capability. Designed for automotive use with 12V DC power supply. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

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

Features at a Glance

Key components: MOSFET power supply, 4-channel amplification, crossover controls, input options, protection circuitry.

Feature	Description
MOSFET Power Supply	High-efficiency switching power supply for clean power delivery
Power Output	50W RMS x 4 channels at 4 ohms
RCA Inputs	Low-level inputs for head unit connection
Speaker-level Inputs	High-level inputs for factory radio integration
Crossover Controls	Variable high-pass and low-pass filters
Bass Boost	+12dB boost at 45Hz
Remote Turn-on	Remote amplifier turn-on capability
Protection Circuitry	Thermal, short-circuit, and DC offset protection
Power Indicator	LED power status indicator
Fuse Protection	Internal fuse for overload protection

Installation

Unpack and inspect contents. Choose suitable mounting location.

Disconnect negative battery terminal before installation.
Mount amplifier: Secure to solid surface with provided hardware.
Connect power: Run 4-gauge power wire from battery to amplifier.
Connect ground: Use short, thick wire to clean chassis ground point.
Connect remote turn-on: Connect to head unit remote turn-on wire.
Connect speakers: Use appropriate gauge speaker wire.
Connect audio inputs: Use RCA cables or speaker-level inputs.

WARNING! Ensure proper ventilation; do not mount near heat sources. Use correct fuse rating.

First-Time Setup

Reconnect battery; verify connections; power on system.

Set input level: Adjust gain control for proper input matching.
Configure crossovers: Set high-pass/low-pass frequencies as needed.
Adjust bass boost: Set to desired level (if used).
Test all channels: Verify proper operation of all four channels.
Fine-tune settings: Make final adjustments for optimal sound quality.

CAUTION! Set gain properly to avoid distortion and speaker damage.

Specifications

Power Output: 50W RMS x 4 channels at 4 ohms
MOSFET Power Supply: High-efficiency design
Frequency Response: 10Hz - 50kHz (+0, -1dB)
Signal-to-Noise Ratio: >95dB
Total Harmonic Distortion: <0.08%
Crossover: Variable 50Hz - 200Hz
Bass Boost: +12dB at 45Hz
Input Sensitivity: 200mV - 4V
Power Supply: 12V DC automotive
Fuse Rating: 25A x 2

Controls and Settings

Front/Rear panel controls: Gain, crossover frequency, bass boost, input selection.

Control Locations: Gain controls (front/rear), crossover controls, bass boost, input mode switch.

Gain: Adjust input sensitivity (200mV - 4V). Crossover: High-pass (50-200Hz) for front/rear channels. Bass Boost: +12dB at 45Hz. Input Mode: Select RCA or speaker-level input. Protection: Thermal, short-circuit, and DC offset protection auto-engage.

Connecting Components

Power connections: Battery (+12V), ground, remote turn-on. Audio connections: RCA inputs or speaker-level inputs. Speaker connections: 4-channel output.

Disconnect battery before making connections.
Use proper gauge wire for power and speakers.
Route power and signal cables separately.
Ensure all connections are secure and insulated.
Connect remote turn-on to head unit blue wire.

Tip: Use quality RCA cables and keep them away from power wires to reduce noise.

Operation Guide

Supports full-range, high-pass, or low-pass operation.

Power on: System turns on with head unit.
Input selection: Choose RCA or speaker-level input via mode switch.
Gain adjustment: Set to match head unit output level.
Crossover setup: Configure for speaker application (full-range, high-pass, or bi-amp).
Bass boost: Engage if additional bass reinforcement needed.
Monitor operation: Check power LED and listen for distortion.
Shutdown: System turns off with head unit or ignition.

WARNING! Do not operate with loose connections. Monitor for overheating.

Protection Features

Thermal Protection: Auto-shutdown if overheating detected. Short-Circuit Protection: Protects against speaker wire shorts. DC Offset Protection: Prevents DC voltage to speakers. Over-current Protection: Limits current during faults.

Care & Maintenance

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

CAUTION! Do not use chemicals or water for cleaning. Keep free of dust and debris.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits. Copyright © 2006 Kenwood Corporation; trademarks of Kenwood USA Corporation. For support, visit www.kenwood.com or contact 1-800-536-9663.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Power connections/fuse	Check battery, ground, remote connections; verify fuse condition.
No sound	Input connections/settings	Verify RCA/speaker inputs; check gain settings; ensure head unit on.
Distortion	Gain setting/clipping	Reduce gain setting; check head unit volume; verify proper input level.
Overheating	Ventilation/load	Improve ventilation; check speaker impedance; reduce gain/bass boost.
Protection mode	Short circuit/overload	Check speaker wires for shorts; verify proper impedance; allow cool-down.

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

Service: 1-800-536-9663; www.kenwood.com