Gravity GR-EQ9 7-Band 1/2 DIN Car Audio Equalizer

The Gravity GR-EQ9 is a compact 7-band car audio graphic equalizer and preamp designed to give an aftermarket sound system more precise tonal control. It lets users adjust key bass, midrange, and treble regions rather than relying only on a radio's basic tone controls. The unit is intended for systems using external amplifiers and RCA-level signal connections.

Each of the seven EQ bands addresses a fixed center frequency, allowing targeted adjustments for low-end weight, vocal presence, and high-frequency detail. Its boost/cut range supports corrective tuning for vehicle acoustics as well as personal listening preferences. Dedicated master-volume, front/rear fader, and subwoofer-level controls keep key system adjustments accessible from the equalizer.

For subwoofer integration, the GR-EQ9 includes a dedicated stereo subwoofer output and selectable subwoofer-frequency control. This helps route a separate signal to a subwoofer amplifier while retaining independent level adjustment. Front and rear stereo RCA outputs are also provided for multi-amplifier installations.

The GR-EQ9 incorporates an auxiliary stereo RCA input in addition to its main input, with a front-panel selector for choosing between the two sources. Its 7V RMS maximum preamp output is designed to provide a strong signal to compatible amplifiers. Gold-plated RCA connectors are specified for the signal connections.

Built in a compact 1/2 DIN format, this equalizer is suited to under-dash, console, or custom-panel installations where space is limited. It operates from a negative-ground 11V to 15V DC vehicle electrical system. The GR-EQ9 can serve as a straightforward signal-control stage when upgrading a factory or aftermarket source unit with amplifiers and a subwoofer.

Key Features

• Seven-Band Graphic EQ: Adjusts seven fixed frequency ranges for more tailored system tuning.
• ±12 dB Equalization Range: Provides meaningful boost or cut at each graphic EQ band.
• 7V RMS Preamp Output: Supplies a higher-voltage RCA signal to compatible amplifiers.
• Three Stereo RCA Outputs: Supports separate front, rear, and subwoofer amplifier signal paths.
• Subwoofer Level Control: Allows convenient adjustment of subwoofer output from the equalizer.
• Auxiliary RCA Input: Adds a selectable stereo input for an additional source device.

Design & Installation

The GR-EQ9 uses a compact black 1/2 DIN chassis with a removable trim ring and ISO-style mounting provisions specified for custom installations. Its front panel combines rotary controls for volume, fader, subwoofer level, and EQ adjustment. The rear panel uses RCA connections for main input, auxiliary input, and front, rear, and subwoofer outputs.

Install the unit in a secure, accessible location such as beneath the dashboard, in a center console, or in a custom panel. Connect its main RCA input to the source unit, then run the front, rear, and subwoofer RCA outputs to the appropriate amplifier inputs. The equalizer requires +12V power, chassis ground, and a remote turn-on connection; an inline fuse is recommended for the power lead.