SoundXtreme ST-AP5 Digital Bass Machine Processor

The SoundXtreme ST-AP5 is a car-audio digital bass machine processor designed to give users more direct control over low-frequency signal adjustment. It is intended for systems where the listener wants to tailor bass level and bass equalization separately from the source unit. Its dash-mount remote-control feature makes routine bass-level adjustment more convenient from the front of the vehicle.

This processor is suited to car-audio upgrades that include a dedicated amplifier and subwoofer stage, as well as systems needing more bass-focused tuning controls. It provides bass output control, parametric bass controls, and a PFM subsonic-filter control. These functions let an installer configure the low-frequency signal according to the goals and limits of the connected audio system.

The ST-AP5 is specified with a 10 Hz to 100 kHz frequency response, 0.003% total harmonic distortion, and a 130 dB signal-to-noise ratio. It also lists balanced-input noise rejection at 60 dB. Together, these published specifications describe a processor designed for clean signal handling within a car-audio installation.

A PWM high-headroom power supply supports the processor's signal-processing section, while the listed output level is 13.5 volts. The bass equalization circuit and adjustable bass controls provide a focused way to shape the bass presentation before the signal reaches downstream amplification. This makes the ST-AP5 a practical component for users who want bass tuning beyond a standard head-unit control.

The processor can be incorporated as part of a signal path between the source unit and an amplifier. Its compact published dimensions make it appropriate for discreet placement where controls and connections remain accessible. Use it as a dedicated bass-management component when building or refining a custom car-audio system.

Key Features

• Dash-Mount Remote Control: Keeps bass-level adjustment accessible from the driver's area.
• Parametric Bass Controls: Provides adjustable bass-focused signal tuning.
• PFM Subsonic Filter Control: Adds adjustable low-frequency filter control.
• Bass Equalization Circuit: Lets installers shape the bass response.
• 13.5V Output Level: Supports a strong signal level for connected equipment.
• PWM Power Supply: Uses a high-headroom PWM supply design.

Design & Installation

The ST-AP5 is a compact car-audio signal processor with a published size of 5.2 x 3.9 x 1.8 inches and a listed weight of 2 pounds. Its design centers on bass-processing adjustments, including bass output, parametric bass, and PFM subsonic-filter controls. Specific enclosure materials and finish details are not published in the confirmed product information.

Install the processor in a secure, accessible location within the vehicle and plan the system layout so the dash-mount remote can be used conveniently. It should be integrated into a compatible car-audio signal path with the appropriate source and downstream amplification equipment. Adjust bass level, equalization, and the PFM subsonic filter gradually during system setup to suit the connected speakers, subwoofer enclosure, and amplifier configuration.