Hertz MP 300 D4.3 12" Dual 4-Ohm Subwoofer

The Hertz MP 300 D4.3 is a 12-inch component subwoofer designed for car audio systems that need substantial low-frequency output without requiring an oversized enclosure. Its dual 4-ohm voice-coil configuration gives installers flexibility when matching the subwoofer to a compatible amplifier. It is intended for custom sealed or reflex enclosure installations rather than use as a powered or preloaded subwoofer.

With 600 watts continuous power handling and 1,200 watts peak power handling, the MP 300 D4.3 is suited to systems built around a dedicated subwoofer amplifier. Its 86 dB sensitivity and 24 Hz resonant frequency support low-bass extension when it is installed in an appropriately designed enclosure. The 4+4-ohm coil arrangement can be wired for different final impedance loads depending on the amplifier and system plan.

The woofer uses a water-repellent pressed-paper cone with mineral powders and an exponential V-cone profile. This construction is designed to combine stiffness with damping while helping the cone retain its shape through long excursions. A Boundary Free IIR rubber surround increases the usable radiating area while retaining the driver’s nominal 12-inch format.

Hertz equips this subwoofer with a 65.5 mm CCAW four-layer voice coil wound on TIL-P material. Venting behind the winding supports heat dissipation, while the compact ferrite motor provides the magnetic field for the coil assembly. The 17 mm Xmax and ±27 mm Xmech specifications make careful enclosure design, crossover setup, and amplifier gain adjustment important.

The MP 300 D4.3 fits well in a system where the front speakers handle midrange and high frequencies while a dedicated amplifier and enclosure handle bass duties. Hertz provides sealed and reflex enclosure reference designs, allowing the installer to prioritize compactness or a ported alignment. Its 164 mm mounting depth and 287 mm cutout requirement should be checked against the intended enclosure before installation.

Key Features

• 600 W Continuous Power: Supports use with a properly matched dedicated subwoofer amplifier.
• Dual 4-Ohm Voice Coils: Provides wiring flexibility for compatible amplifier load requirements.
• 65.5 mm CCAW Coil: Four-layer coil construction supports sustained power handling.
• V-Cone Profile: Helps maintain cone stiffness during high-excursion bass playback.
• Boundary Free Surround: Uses IIR rubber to maximize usable cone radiating area.
• Aluminum Alloy Basket: Six-spoke frame includes venting beneath the spider.

Design & Installation

The MP 300 D4.3 uses a high-density-flux ferrite magnet, water-repellent pressed-paper cone, IIR rubber surround, and anti-resonant aluminum alloy basket. Its basket has a six-spoke structure with integrated venting below the spider, while the terminal block accepts cable up to 8 AWG. A protective plastic terminal cover is fitted to help prevent accidental short circuits.

Plan for a 287 mm (11.30 in.) mounting cutout, 164 mm (6.46 in.) mounting depth, and 302 mm (11.89 in.) center-to-center mounting distance. Hertz lists a 28 L sealed enclosure reference and a 36 L reflex enclosure reference, both using 19 mm material. Wire the dual 4-ohm coils in series for an 8-ohm load or in parallel for a 2-ohm load only when the amplifier is rated to operate safely at that impedance.