PowerBass PBX-500.4 Full Range Digital Amplifier User Manual

1. Introduction

1.1 Product Overview

The PowerBass PBX-500.4 is a high-efficiency full-range Class D digital amplifier designed for automotive audio systems. This 4-channel amplifier delivers robust audio power while minimizing energy consumption. It incorporates advanced circuitry for sound optimization, including a PWM MOSFET power supply and a high damping control circuit, ensuring precise and clean audio output.

Key features include a variable subsonic filter, a 40-click variable detent high/low pass electronic crossover, and an LPF/HPF/x10 bandpass filter selector switch for extensive audio customization. The amplifier is equipped with a comprehensive protection circuit to guard against impedance overload, speaker short circuits, thermal overheating, and DC output, ensuring stable and reliable operation. It is a 2-ohm stable four-channel amplifier with a double-sided copper-plated PCB and high current voltage ripple rejection circuitry.

Figure 1.1: The PowerBass PBX-500.4 amplifier, showcasing its compact black brushed aluminum chassis with a central illuminated logo.

1.2 Safety Information

• Always disconnect the vehicle's battery negative terminal before beginning any installation.
• Ensure all wiring is properly routed and secured to prevent damage or short circuits.
• Avoid mounting the amplifier in areas exposed to direct sunlight, excessive heat, moisture, or dust.
• Use appropriate gauge wiring for power and ground connections as specified in the installation section.
• Consult a professional installer if you are unsure about any part of the installation process.

2. Setup and Installation

2.1 Unpacking

Carefully remove the amplifier from its packaging. Inspect the unit for any signs of damage that may have occurred during shipping. Retain the packaging for future use or in case of return.

2.2 Mounting

Select a mounting location that provides adequate ventilation for the amplifier to dissipate heat. Avoid mounting on carpeted surfaces or in enclosed spaces without airflow. Secure the amplifier firmly using the provided mounting hardware to prevent movement during vehicle operation.

2.3 Wiring Connections

Proper wiring is crucial for optimal performance and safety. Refer to the diagram below for input and gain controls.

Figure 2.1: Close-up view of the amplifier's input section, showing CH1, CH2, CH3, CH4 RCA inputs and corresponding gain adjustment knobs.

• Power (B+): Connect a heavy-gauge power cable directly from the positive terminal of the vehicle's battery to the amplifier's B+ terminal. Install an appropriate fuse (not supplied) within 18 inches of the battery.
• Ground (GND): Connect a heavy-gauge ground cable from the amplifier's GND terminal to a clean, unpainted metal surface on the vehicle's chassis. The ground cable should be as short as possible.
• Remote (REM): Connect a remote turn-on wire from your head unit's remote output to the amplifier's REM terminal. The amplifier also features an auto turn on/off function and a remote soft delay turn on/off circuit.
• RCA Inputs: Connect the RCA output cables from your head unit or signal processor to the amplifier's CH1, CH2, CH3, and CH4 RCA input jacks. The amplifier features balanced RCA inputs.
• Speaker Outputs: Connect your speakers to the amplifier's speaker output terminals. Ensure correct polarity (+ to + and - to -) and verify that the speaker impedance is within the amplifier's supported range (2-ohm stable per channel).

3. Operation and Adjustments

After all connections are made and verified, you can power on the system and begin adjusting the amplifier settings. Refer to the diagram below for gain and crossover controls.

Figure 3.1: Close-up view of the amplifier's control panel, showing gain adjustment knobs, HPF/LPF/x10 switches, and ON/OFF switches for filters.

3.1 Initial Power-Up

Turn on your head unit. The amplifier should power on, indicated by its status light. If the amplifier does not power on, refer to the Troubleshooting section.

3.2 Gain Control

The gain controls (MIN/MAX) adjust the input sensitivity of the amplifier to match the output voltage of your head unit. To set the gain:

1. Turn the amplifier's gain controls to their minimum (MIN) setting.
2. Set your head unit's volume to about 75% of its maximum level.
3. Slowly increase the amplifier's gain control until you hear slight distortion, then back it off slightly until the sound is clear.

3.3 Crossover Settings

The PBX-500.4 features a 40-click variable detent high/low pass electronic crossover and an LPF/HPF/x10 bandpass filter selector switch.

• HPF (High Pass Filter): Allows frequencies above the set point to pass through to the speakers. Useful for protecting smaller speakers from low bass frequencies. The frequency range is typically 20Hz-800Hz or 200Hz-8KHz when the x10 switch is engaged.
• LPF (Low Pass Filter): Allows frequencies below the set point to pass through. Typically used for subwoofers. (Note: This amplifier is full-range, so LPF might be used for specific channel configurations or if a subwoofer is connected to a bridged channel).
• x10 Switch: Multiplies the selected crossover frequency by 10, extending the adjustment range for the HPF.
• Subsonic Filter: A variable subsonic filter is included to remove extremely low, inaudible frequencies that can waste amplifier power and damage subwoofers.

Adjust these filters to optimize the sound for your specific speaker setup and personal preference.

4. Maintenance

4.1 Cleaning

Periodically clean the amplifier's exterior with a soft, dry cloth. Avoid using harsh chemicals or abrasive cleaners. Ensure ventilation fins are free from dust and debris to maintain proper cooling.

4.2 Inspection

Regularly inspect all wiring connections for tightness and corrosion. Check for any signs of wear or damage to cables. Ensure the amplifier is securely mounted.

5. Troubleshooting

If you experience issues with your PowerBass PBX-500.4 amplifier, consult the following common troubleshooting steps:

• No Power: Check the in-line fuse near the battery. Verify all power, ground, and remote turn-on connections are secure and properly wired. Ensure the vehicle's battery has sufficient charge.
• No Sound Output: Confirm that the head unit is on and sending a signal. Check RCA input connections. Verify speaker wire connections and ensure no shorts. Adjust gain settings.
• Distorted Sound: Reduce the amplifier's gain setting. Check speaker impedance to ensure it matches the amplifier's capabilities. Ensure the audio source is not distorted.
• Amplifier Goes into Protection Mode: This usually indicates an issue such as overheating, a speaker short circuit, or an impedance overload. Check speaker wiring for shorts. Ensure adequate ventilation around the amplifier. Allow the amplifier to cool down if it's hot.
• Noise (Hissing, Whining): Check for proper grounding of the amplifier and head unit. Ensure RCA cables are not routed near power cables.

6. Specifications

7. Warranty and Support

7.1 Warranty Information

The PowerBass PBX-500.4 amplifier comes with a 1-Year Manufacturer Warranty. Please retain your proof of purchase for warranty claims. The warranty covers defects in materials and workmanship under normal use.

7.2 Customer Support

For technical assistance, warranty service, or further inquiries, please contact PowerBass customer support directly. Refer to the official PowerBass website for current contact information.