1. Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your Quantum Class AB 4 Channel Amplifier, model QPX20004. Please read this manual thoroughly before attempting to install or operate the amplifier to ensure proper function and to prevent damage to the unit or your vehicle's audio system. Retain this manual for future reference.
2. Safety Information
- Professional Installation Recommended: For optimal performance and safety, professional installation by a qualified technician is highly recommended.
- Power Disconnection: Always disconnect the vehicle's negative battery terminal before starting any installation work to prevent electrical shorts.
- Proper Wiring: Ensure all wiring is correctly connected and insulated to prevent short circuits and potential damage. Use appropriate gauge wires for power and ground connections.
- Ventilation: Install the amplifier in a location that allows for adequate ventilation. Avoid covering the amplifier or installing it in enclosed spaces where heat cannot dissipate.
- Moisture and Heat: Do not expose the amplifier to moisture, water, or extreme temperatures.
- Fuse Protection: Always use the correct fuse rating as specified in the specifications section.
- Hearing Protection: Prolonged exposure to high volume levels can cause permanent hearing damage. Adjust volume to a safe level.
3. Package Contents
Verify that all items are present in the package:
- Quantum Class AB 4 Channel Amplifier QPX20004
- Instruction Manual (this document)
- Mounting Hardware (screws, etc. - specific items may vary)
4. Features
- Class A/B Circuitry: Delivers high-quality audio reproduction.
- 4-Channel Output: Provides power for multiple speakers.
- Variable Crossover Network: Allows customization of frequency distribution to speakers (high-pass and low-pass filters).
- 2 Ohm Stable: Capable of handling a 2 Ohm load in stereo mode.
- Adjustable Bass Boost: Offers 0, 6, or 12 dB bass boost settings.
- High-Efficiency MOSFET Design: For optimal power efficiency.
- Speaker Short Circuit Protection: Integrated safety feature.
- Buffered Line Output: For easy daisy-chaining to additional amplifiers.
- Compact Design: Dimensions of 13.7 inches x 8.6 inches x 1.96 inches.
5. Setup
5.1 Mounting the Amplifier
Choose a mounting location that is dry, well-ventilated, and secure. Avoid mounting the amplifier directly on carpet or in areas prone to excessive vibration or heat. Ensure sufficient space around the amplifier for air circulation.
- Place the amplifier in the desired location and mark the mounting holes.
- Drill pilot holes if necessary, ensuring no wires or fuel lines are damaged.
- Secure the amplifier using the provided mounting screws.
5.2 Wiring Connections
Before making any connections, ensure the vehicle's battery is disconnected. Refer to the diagram below for visual guidance on connections (Note: A generic connection diagram is described as no specific diagram is provided.)
This image displays the Quantum Class AB 4 Channel Amplifier QPX20004. The amplifier features a black, ribbed casing designed for heat dissipation. The 'Quantum Audio' logo is centrally located on the top surface and is illuminated with an amber glow. Below the logo, the model number 'QPX20004' and '4 CHANNEL AMPLIFIER' are visible, along with '2200 WATTS' on the right side. The overall design is sleek and functional.
5.2.1 Power Connection
- Connect the +12V (B+) terminal of the amplifier to the positive terminal of the vehicle's battery using a heavy-gauge power cable. Install an in-line fuse holder within 18 inches (45 cm) of the battery.
- Connect the GND (Ground) terminal of the amplifier to a clean, unpainted metal surface of the vehicle chassis. Ensure a solid, low-resistance connection.
- Connect the REM (Remote Turn-On) terminal to the remote output lead of your head unit. This wire turns the amplifier on and off with your stereo.
5.2.2 Speaker Connections
- Connect your speakers to the amplifier's speaker output terminals (CH1, CH2, CH3, CH4). Ensure correct polarity (+ to + and - to -).
- This amplifier is 2 Ohm stable in stereo mode. Verify your speaker impedance before connecting.
5.2.3 Signal Input Connection
- Connect the RCA output cables from your head unit to the amplifier's RCA input jacks (INPUT CH1/2, INPUT CH3/4).
6. Operating the Amplifier
6.1 Gain Adjustment
The gain control (often labeled 'LEVEL') matches the amplifier's input sensitivity to the output of your head unit. Start with the gain set to minimum. Play a familiar track at about 75% of your head unit's maximum volume. Slowly increase the amplifier's gain until you hear distortion, then back it off slightly.
6.2 Variable Crossover Network
The QPX20004 features variable high-pass (HPF) and low-pass (LPF) crossovers for each channel pair (CH1/2 and CH3/4). These allow you to direct specific frequency ranges to your speakers, optimizing sound quality and protecting speakers from frequencies they cannot reproduce.
- HPF (High-Pass Filter): Allows frequencies above the set point to pass through. Useful for full-range speakers or tweeters to prevent low bass.
- LPF (Low-Pass Filter): Allows frequencies below the set point to pass through. Essential for subwoofers to prevent high frequencies.
- Adjust the crossover points according to your speaker types and desired sound.
6.3 Bass Boost
The bass boost control allows you to enhance low frequencies at 0, 6, or 12 dB. Use this feature sparingly and adjust carefully to avoid distortion or damage to speakers, especially subwoofers.
6.4 Buffered Line Output
The buffered line output provides an RCA signal that can be used to daisy-chain the audio signal to another amplifier without signal degradation. Connect an RCA cable from this output to the input of the next amplifier.
7. Maintenance
- Cleaning: Periodically clean the amplifier's exterior with a soft, dry cloth. Do not use harsh chemicals or abrasive cleaners.
- Ventilation: Ensure the cooling fins remain free of dust and debris to maintain proper heat dissipation.
- Connections: Occasionally check all wiring connections to ensure they are secure and free from corrosion.
8. Troubleshooting
If you experience issues with your amplifier, consult the following table before contacting support.
| Problem | Possible Cause | Solution |
|---|---|---|
| No Power / Amplifier Not Turning On | Blown fuse; Loose power/ground/remote wire; Faulty remote turn-on signal. | Check and replace fuse; Verify all power, ground, and remote connections; Test remote wire for 12V signal. |
| No Sound Output | RCA cables disconnected; Speaker wires disconnected or shorted; Gain set too low; Head unit not providing signal. | Check RCA connections; Inspect speaker wiring for shorts or disconnections; Adjust gain; Verify head unit output. |
| Distorted Sound | Gain set too high; Speaker impedance too low; Faulty speakers; Poor ground connection. | Reduce gain; Verify speaker impedance is within limits; Test speakers; Check ground connection for tightness. |
| Amplifier Overheating (Protection Mode) | Insufficient ventilation; Speaker impedance too low; Prolonged high volume use. | Ensure adequate airflow around amplifier; Verify speaker impedance; Reduce volume or allow amplifier to cool. |
9. Specifications
| Feature | Specification |
|---|---|
| Model | QPX20004 |
| Amplifier Class | Class AB |
| Channels | 4 Channel |
| Output Power | Up to 2200 Watts (Peak) |
| Minimum Impedance (Stereo) | 2 Ohms |
| Crossover Type | Variable High-Pass and Low-Pass |
| Bass Boost | 0, 6, 12 dB |
| Dimensions (L x W x H) | 13.7 inches x 8.6 inches x 1.96 inches |
| Item Weight | 5.52 pounds |
| Manufacturer | Quantum Audio |
10. Warranty and Support
Quantum Audio products are designed for reliability and performance. For specific warranty terms and conditions, please refer to the warranty card included with your product or visit the official Quantum Audio website. In case of technical issues or questions not covered in this manual, please contact Quantum Audio customer support or your authorized dealer for assistance.
