Directed 1500d Manual

The Directed 1500d is a high-performance car audio amplifier delivering 1500 watts RMS power, featuring Class D technology for efficient operation, variable low-pass crossover (50-250Hz), bass boost control, remote bass level control capability, speaker-level inputs, preamp outputs, thermal/overload/short circuit protection, and MOSFET power supply. Designed for 12V DC automotive systems. 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 Devices 7. Operation Guidelines 8. Protection Features 9. Care & Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: High-power Class D amplifier, Remote bass control, Speaker-level inputs, Preamp outputs, Protection circuitry.

Feature	Description
Power Output	1500 watts RMS at 1 ohm
Class D Technology	High efficiency amplifier design
Low-Pass Crossover	Variable 50-250Hz
Bass Boost	0-18dB boost at 45Hz
Remote Bass Control	Optional remote level adjustment
Speaker-level Inputs	For factory radio integration
Preamp Outputs	For daisy-chaining multiple amplifiers
Protection Circuitry	Thermal, overload, and short circuit protection
MOSFET Power Supply	Stable power delivery
DC Offset Protection	Prevents speaker damage

Installation

Unpack and inspect contents. Choose suitable mounting location.

Disconnect vehicle battery: Remove negative terminal first for safety.
Mount amplifier: Secure to stable surface using provided hardware.
Connect power: Run 4-gauge power wire from battery to amplifier.
Connect ground: Use short, thick ground wire to vehicle chassis.
Connect remote turn-on: Wire to head unit remote turn-on lead.
Connect speakers: Use appropriate gauge speaker wire.
Connect audio inputs: Use RCA cables or speaker-level inputs.

WARNING! Amplifier generates heat; ensure adequate ventilation. Use proper fuse rating.

First-Time Setup

Reconnect battery; power on system; adjust settings.

Set gain control: Start at minimum, adjust while playing music.
Set low-pass crossover: Adjust for subwoofer application (80Hz typical).
Set bass boost: Use sparingly to avoid distortion.
Test operation: Play audio at various volume levels.
Fine-tune settings: Adjust based on listening preferences.

CAUTION! Avoid setting gains too high to prevent clipping and speaker damage.

Specifications

RMS Power: 1500 watts @ 1 ohm
Peak Power: 3000 watts
Frequency Response: 20Hz-250Hz
Signal-to-Noise Ratio: >95dB
Crossover: Variable low-pass 50-250Hz
Bass Boost: 0-18dB @ 45Hz
Input Sensitivity: 200mV-6V
Operating Voltage: 11-16V DC
Fuse Rating: 120A
Dimensions: Standard amplifier footprint

Controls and Settings

Access controls via front panel knobs and switches.

Front Panel: Power indicator, Gain control, Low-pass frequency, Bass boost, Phase switch.

Gain: Adjust input sensitivity to match head unit output. Low-Pass: Set crossover frequency for subwoofers. Bass Boost: Increase low-frequency output. Phase: 0/180 degree switch for proper speaker alignment. Remote Bass: Optional remote control for bass level adjustment.

Connecting Devices

Power: Battery connection. Audio: RCA inputs or speaker-level. Speakers: Output terminals.

Disconnect battery before making connections.
Use proper gauge wiring for power and speakers.
Connect RCA cables from head unit to amplifier.
Connect speaker wires observing proper polarity.
Secure all connections tightly.

Tip: Keep power and signal cables separated to avoid noise.

Operation Guidelines

Designed for subwoofer amplification in car audio systems.

Power on: System turns on with head unit remote lead.
Volume control: Adjust at head unit, not amplifier.
Gain setting: Set properly to avoid distortion.
Bass adjustment: Use remote control if installed.
Thermal management: Ensure adequate airflow around amplifier.
Power handling: Match amplifier power to speaker ratings.

WARNING! Do not operate with impedance below specified minimum. Avoid moisture exposure.

Protection Features

Thermal Protection: Automatically reduces output if overheating detected. Overload Protection: Protects against excessive current draw. Short Circuit Protection: Prevents damage from output shorts. DC Offset Protection: Monitors output for DC voltage.

Care & Maintenance

Keep amplifier clean and dry. Check connections periodically for tightness.

CAUTION! Do not use liquids for cleaning. Ensure proper ventilation during operation.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for vehicle use. Copyright © 2025 Directed; trademarks of Directed Electronics. For technical support, visit www.directed.com or contact 1-800-876-0800.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Wiring/fuse	Check power, ground, remote connections; inspect fuse.
No sound	Input/settings	Verify input connections; check gain setting; test source.
Distorted sound	Gain/clipping	Reduce gain setting; check head unit volume.
Protection mode	Overheating/short	Allow cooling; check for short circuits; verify impedance.
Poor bass response	Crossover/settings	Adjust low-pass frequency; check bass boost setting.

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

Service: 1-800-876-0800; www.directed.com