AMERICAN BASS ABX-3.1A - User Manual

The American Bass ABX-3.1A is a three-way active electronic crossover with line drive, designed to enhance audio system performance by precisely routing audio signals to the appropriate speakers. This user's manual provides comprehensive information on its features, functions, installation, and troubleshooting.

Function Description

The ABX-3.1A acts as a sophisticated audio signal processor, splitting a full-range audio signal into distinct frequency bands (high, mid, and low) and directing them to specific amplifiers and speakers. This ensures that each speaker receives only the frequencies it is designed to reproduce, leading to clearer sound, improved dynamics, and reduced distortion.

Key Functions:

• Power Input Terminal (12V): Provides the main power connection for the device.
• Ground Input Terminal: Connects the device to the vehicle's chassis ground for stable operation.
• Remote Turn-On Input Terminal (Remote): Allows the crossover to be turned on and off in conjunction with the head unit or other audio components.
• Power Indicator: Illuminates to show that the device is powered on.
• Front Input: Receives the front channel audio signal from the head unit.
• Front and Rear Parallel Switch Select: Determines whether the front and rear inputs operate independently or in parallel.
• Rear Input: Receives the rear channel audio signal from the head unit.
• Sub Input: Receives the subwoofer channel audio signal.
• Front High Pass Control: Adjusts the high-pass crossover frequency for the front speakers, allowing only frequencies above the set point to pass.
• Rear High Pass Control: Adjusts the high-pass crossover frequency for the rear speakers.
• Front Frequency Multiplier Control: Multiplies the selected front high-pass frequency by a factor (e.g., x1 or x20) for broader adjustment.
• Sub Frequency Control: Adjusts the low-pass crossover frequency for the subwoofer, allowing only frequencies below the set point to pass.
• Boost Frequency Control: Selects the center frequency for the bass boost function.
• Sub Boost Control: Adjusts the level of bass boost at the selected boost frequency.
• Front Output Level Control: Adjusts the output gain for the front channels.
• Front Output: Sends the processed front channel audio signal to the front amplifier.
• Rear Output Level Control: Adjusts the output gain for the rear channels.
• Rear Output: Sends the processed rear channel audio signal to the rear amplifier.
• Sub Output Level Control: Adjusts the output gain for the subwoofer channel.
• Sub Output: Sends the processed subwoofer channel audio signal to the subwoofer amplifier.
• Remote Sub Level Control: Allows for remote adjustment of the subwoofer output level.
• Sub Phase Switch Select: Inverts the phase of the subwoofer output (0° or 180°) to optimize bass response and blend with other speakers.

Important Technical Specifications

• Supply Voltage: 11-15V DC
• Input Current: 0.3amp max
• Distortion: 0.01% THD
• Frequency Response: 10Hz-50KHz (-3dB)
• S/N Ratio (A Weighted): >95dB
• Separation: 60dB
• Crossover Frequencies (Continuously Variable):
  • Front High-pass (x1): 35-400Hz
  • Front High-pass (x20): 700-8KHz
  • Rear High-pass (x1): 35-400Hz
  • Sub Low-pass: 45-250Hz
• Sub Boost: Single octave 0dB to 18dB (variable) at 40 to 120Hz (variable)
• Input Impedance: >10K Ohms
• Output Impedance: <1K Ohms
• Output Voltage Level: 9 volts max.

Usage Features

The ABX-3.1A offers flexible configuration options to suit various audio system setups, including 2-channel, 3-channel, and 4-channel systems.

System Adjustment:

• Preliminary Adjustments: Before fine-tuning, ensure all amplifier input gains are set to half of maximum.
• Crossover Point Setting: Turn the audio system on, preset/adjust the front, rear, and sub-woofer output level controls, as well as the front channel high-pass and sub-woofer channel low-pass crossover points.
• Volume Adjustment: Slowly turn up the volume and listen carefully for distortion or sound loss. If issues arise, refer to the "Trouble Shooting Guide."

Audio Connections:

• Power: Connect the 12V terminal to the positive battery terminal (constant 12V source).
• Ground: Connect to the vehicle's chassis ground (check for good ground).
• Remote: Connect to the remote control wire (or the electrical antenna) of the car radio/cassette deck.
• Input/Output:
  • Front Input: Connect from pre-amp output of radio/tape player (or CD) into the crossover module.
  • Rear Input: Connect from pre-amp output of radio/tape player (or CD) into the crossover module.
  • Sub Input: Connect from pre-amp output of radio/tape player (or CD) into the crossover module.
  • Front Output: Connect from "front output" of the crossover module to the front amplifier input.
  • Rear Output: Connect from "rear output" of the crossover module to the rear amplifier input.
  • Sub-woofer Output: Connect from "sub-woofer output" of the crossover to the sub-woofer amplifier input.

System Configurations:

• 2-Channel Two-way System (Tweeter + Full Range): Car receiver feeds into the crossover, which then outputs to a power amp for tweeters and another power amp for full-range speakers. No sub output is used.
• 2-Channel Two-way System (Tweeter + Woofer): Car receiver feeds into the crossover, which then outputs to a power amp for tweeters and another power amp for woofers. No front output is used.
• 4-Channel TRI-AMP System: Car receiver feeds into the crossover (front, rear, and sub inputs). The crossover outputs to power amps for front speakers, rear speakers, and a sub woofer. This configuration provides a comprehensive multi-way active setup.

Maintenance Features

The manual emphasizes proper installation and troubleshooting to ensure the longevity and optimal performance of the device.

Precautions:

• Short Circuits: To prevent short circuits, disconnect the negative battery ground lead before wiring the system.
• Installation Check: Verify all connections are correctly made before powering up the system.
• Negative Battery Ground: Remove all car parts that were removed and reconnect the negative battery ground lead.
• Noise Check:
  • Start the engine.
  • Turn the audio system on.
  • Rev the engine and vary the volume of the audio system to determine if there is any unwanted noise. If so, turn both the audio system and the engine off. Do not secure the crossover mounting screws.
  • If the audio system does not have any noise, securely tighten the crossover mounting screws and double-check the wiring cables for safe placement.

Troubleshooting Guide:

• Audible Distortion at Low Volume: Possible cause is output levels not set correctly.
• Whining Sound Heard Through Speakers (Engine Running): Check the red power wire; it must be connected directly to the battery. Check the system's ground point; it must make good contact with chassis ground (bare metal). The radio and the crossover must be grounded at the same reference point.
• "Motorboating" Type of Sound (Engine Running, Volume at Reasonable High Level): Check the red power wire; it must be connected directly to the battery. Check the system's ground point; it must make good contact with chassis ground (bare metal).

Installation:

The manual provides diagrams for mounting the crossover using tapping screws, spring washers, and plain washers, ensuring a secure and stable installation within the vehicle.

Caution: Do not route audio cables and power cables together. This can cause engine noise in your audio system. Always disconnect the system from the battery before attempting to make any wiring connections. This product is designed for use in any 12V DC negative ground electrical system only. Installing this product in a positive ground electrical system could seriously damage the audio system.

The American Bass ABX-3.1A is a powerful tool for car audio enthusiasts looking to achieve superior sound quality and system control. Its detailed specifications and user-friendly guide make it accessible for both professional installers and DIY users.