Hifonics HFXR 2/3-Way Active Car Audio Crossover

The Hifonics HFXR is an active electronic crossover and line driver for vehicle audio systems using separate amplifiers for front, rear, and subwoofer channels. It divides the incoming signal into adjustable frequency ranges before the amplifiers, helping route bass, midrange, and high-frequency content to the appropriate speakers. This makes it a practical addition to multi-amplifier systems that need more signal-routing control than an amplifier’s built-in crossover provides.

Designed for 2-way or 3-way operation, the HFXR supports either a 2-channel or 4-channel source connection. Its front/rear input switch can distribute a single front input to both front and rear outputs when a source unit has only one pair of RCA outputs. Separate front, rear, and subwoofer level controls allow the installer to balance each amplifier section during setup.

The front high-pass section includes a selectable frequency multiplier for a wider tuning range, while rear high-pass and subwoofer low-pass controls cover the low-frequency crossover range. A selectable stereo/mono subwoofer output and 180-degree phase switch add flexibility when integrating one or more subwoofers. These controls allow the system to be configured around the speakers, amplifiers, and source unit already in the vehicle.

An integrated 8.5-volt RMS maximum preamp output is intended to provide a strong signal to downstream amplifiers. The HFXR also includes a 45 Hz bass-boost circuit with quasi-parametric equalization and up to 12 dB of adjustment. A supplied remote level control adjusts the low-pass/subwoofer level from an under-dash mounting location.

For an upgrade path, the HFXR can sit between an aftermarket source unit and separate front, rear, and mono subwoofer amplifiers. It provides dedicated RCA connections for front, rear, mixed, and subwoofer signal routing, plus a full-range RCA preamp output for cascading compatible audio components. It is intended for universal 12-volt vehicle applications and should be tuned carefully with amplifier gains and speaker capabilities in mind.

Key Features

• 2-Way/3-Way Processing: Routes audio for front, rear, and subwoofer amplifier sections.
• 2- Or 4-Channel Inputs: Adapts to source units with one or two RCA pairs.
• 8.5V Line Driver: Provides up to 8.5 volts RMS preamp output.
• Adjustable Crossover Controls: Sets high-pass and low-pass points for system tuning.
• Remote Bass Level: Adjusts the subwoofer low-pass level from the driver area.
• Phase And Subwoofer Modes: Select stereo or mono output and 180-degree phase inversion.

Design & Installation

The HFXR uses a compact processor chassis measuring 6.75 by 5.75 by 1.75 inches, with a silver finish and a control layout that groups front, rear, and subwoofer adjustments. Dedicated RCA connections are provided for front and rear inputs, front/rear/sub outputs, and mixed input/output routing. A green power indicator confirms that the processor is switched on.

Install the HFXR in a dry, secure location with enough clearance for RCA cables, power wiring, and the remote-control cable. Connect its +12V terminal to the battery through a 5-amp inline fuse, ground it to the vehicle chassis, and connect the remote turn-on terminal to the source unit or amplifier turn-on lead. Use the front/rear input switch for either a 2-channel or 4-channel source configuration, then set crossover frequencies and output levels gradually while matching the connected amplifiers and speakers.