Memphis Audio PRX624 6.5" Selectable-Impedance Subwoofer

The Memphis Audio PRX624 is a compact 6.5-inch car subwoofer for adding dedicated low-frequency support where a conventional full-size subwoofer may not fit. It is designed for custom enclosures and aftermarket systems that need bass reinforcement without giving up much installation space. Its 150-watt RMS rating makes it suitable for use with a properly matched external amplifier.

This Power Reference Series model is a practical choice for vehicles with limited cargo room, compact custom installs, or multi-subwoofer systems. Its selectable impedance design lets the installer configure the subwoofer for either a 2-ohm or 4-ohm load using the included jumper wires. That flexibility can simplify amplifier matching and future system changes.

The PRX624 is intended for bass frequencies, with a stated frequency response of 50 to 150 Hz. A 6.5-inch subwoofer will not replace the air-moving capability of a larger woofer, but it can provide focused low-end reinforcement in an appropriately designed enclosure. Sealed and vented enclosure recommendations are available for single- and dual-subwoofer applications.

Memphis uses a black polypropylene cone, double-stitched butyl rubber surround, reinforced spider shoulder, and woven tinsel leads in the PRX624. The subwoofer also incorporates DVVC Direct Voice Coil Cooling and a high-temperature TIL voice coil former. These construction details support stable operation at its rated power level.

The PRX624 works well as part of a compact bass upgrade paired with an amplifier that is stable at the selected final impedance. It can be used in a single-sub enclosure for a small-footprint system or in pairs where additional output is desired. Proper enclosure volume, secure mounting, crossover setup, and amplifier gain adjustment are important to its performance and reliability.

Key Features

• Selectable Impedance: Included jumpers configure the subwoofer for 2- or 4-ohm operation.
• 150W RMS Handling: Supports an amplifier delivering up to 150 watts RMS.
• Compact 6.5-Inch Format: Helps fit dedicated bass into space-conscious vehicle installations.
• Polypropylene Cone: Provides a rigid cone surface for low-frequency reproduction.
• Double-Stitched Butyl Surround: Supports cone movement while adding long-term durability.
• DVVC Cooling: Direct Voice Coil Cooling helps manage voice-coil heat under load.

Design & Installation

The PRX624 uses a stamped steel frame, black polypropylene cone, double-stitched butyl rubber surround, reinforced spider shoulder, woven tinsel leads, and a high-temperature TIL voice coil former. Its 41-ounce magnet structure and 1.5-inch voice coil are paired with a compact 3-inch mounting depth. A removable rubber trim ring/gasket is fitted at the mounting surface.

Allow for a 5.67-inch cutout and at least 3 inches of mounting depth, while also checking clearance behind the mounting location. Select the 2-ohm or 4-ohm configuration with the supplied jumper wires before connecting the amplifier, and verify that the amplifier supports that load. Memphis specifies a 0.35-cubic-foot sealed enclosure or a 0.5-cubic-foot vented enclosure for one subwoofer; a vented design uses a 2-inch-diameter, 8.75-inch-long port tuned to 47 Hz.