Memphis EQL7 7-Band Half-DIN Graphic Equalizer

The Memphis EQL7 is a half-DIN, 7-band graphic equalizer and preamp designed to give a car audio system more direct tonal and level control. It fits between a source unit and amplifiers to help correct for vehicle acoustics, speaker placement, or personal listening preferences. This used, very-good-condition unit is suited to systems that use RCA-level signal connections.

Its seven EQ controls cover bass, midrange, and treble frequencies from 50Hz through 16kHz. Each band provides up to 18dB of boost or cut, allowing targeted adjustments instead of relying solely on a head unit's basic tone controls. The result is a more configurable signal before it reaches the amplifiers.

The EQL7 combines equalization with master volume, fader, input selection, and subwoofer-level controls on its front panel. Separate left and right sensitivity adjustments for the main and auxiliary inputs help match the processor to connected source equipment. An adjustable subwoofer-frequency control adds another point of system tuning for installations with a dedicated subwoofer amplifier.

Memphis specifies a low-noise BI-FET op-amp design and an onboard 30V bipolar switching power supply. The unit is rated for a maximum output of 9.75V RMS, with 20dB of headroom to help accommodate strong source signals. Its specified frequency response is 10Hz to 50kHz within +/-1dB.

With its universal half-DIN chassis, the EQL7 is intended for custom dashboards, center consoles, or other accessible mounting locations. It is a signal processor rather than an amplifier, so it requires a compatible 11-15V negative-ground electrical system and RCA-connected downstream equipment. It can be used as a central control point in a multi-amplifier system with front, rear, and subwoofer channels.

Key Features

• Seven-Band Equalization: Adjusts 50Hz, 125Hz, 315Hz, 750Hz, 2.2kHz, 6kHz, and 16kHz bands.
• 18dB Boost/Cut: Provides substantial adjustment range for each equalizer band.
• Main/Aux Input Selection: Lets you select between main and auxiliary signal inputs.
• Independent Input Sensitivity: Left and right controls help match connected source signals.
• Subwoofer Level Control: Provides front-panel adjustment of subwoofer output level.
• High-Voltage Preamp Stage: Delivers up to 9.75V RMS maximum output.

Design & Installation

The EQL7 uses a universal half-DIN chassis, gold RCA input/output jacks, and dual-color backlighting for control visibility. Its low-noise BI-FET op-amp circuit and onboard 30V bipolar switching supply are intended to support a clean preamp signal path. The unit is specified for 11-15V negative-ground electrical systems.

Install the equalizer in an accessible half-DIN opening or custom panel location, then connect it between the source unit and amplifier inputs using RCA cables. Begin setup with EQ controls set flat and input gains at minimum, then match levels gradually to avoid audible distortion. Verify the included hardware and accessories for this used unit before installation, as package contents can vary by individual listing.