Infinity PRIMUS-1270 12" Car Subwoofer

The Infinity PRIMUS-1270 is a 12-inch, 4-ohm component car subwoofer designed to add dedicated low-frequency output to an aftermarket audio system. It is intended for installations where full-range speakers or a factory system need deeper bass support. Because it is sold as a bare subwoofer, it is installed in a compatible enclosure and powered by a separate amplifier.

With 300 watts RMS power handling and a 35 Hz to 200 Hz frequency response, the PRIMUS-1270 is suited to reproducing the bass foundation in music without requiring an oversized amplifier. Its 91 dB sensitivity rating helps it make practical use of available amplifier power. The nominal 4-ohm impedance makes amplifier matching straightforward when the amplifier is rated to drive a 4-ohm subwoofer load.

A 2-inch voice coil supports the subwoofer's stated power-handling capability, while the polypropylene cone and hi-roll rubber surround are designed for automotive use. This combination provides a rigid moving surface with a flexible surround for cone travel. Infinity also specifies a stamped-steel frame to provide a stable mounting structure.

The PRIMUS-1270 can be used in sealed, ported, or prefabricated band-pass enclosures. A sealed enclosure is recommended when space efficiency and a more even in-vehicle response are priorities, while the specified ported alignment emphasizes efficiency in the upper-bass region. The manufacturer also notes that free-air installation is possible with reduced power handling.

This subwoofer fits well into a system upgrade built around an external mono or multi-channel amplifier with a dedicated low-pass output. It can complement upgraded door speakers by moving demanding bass frequencies to a purpose-built driver. Proper enclosure volume, amplifier setup, wiring, and crossover adjustment are important for reliable operation.

Key Features

• 12-Inch Subwoofer: Adds dedicated bass capacity to a car audio system.
• 300W RMS Handling: Supports continuous use with an appropriately matched amplifier.
• 4-Ohm Impedance: Matches amplifiers rated for a 4-ohm speaker load.
• Polypropylene Cone: Provides a lightweight, rigid diaphragm for bass reproduction.
• Hi-Roll Rubber Surround: Supports cone movement and automotive durability.
• Flexible Enclosure Options: Works with sealed, ported, and band-pass designs.

Design & Installation

The PRIMUS-1270 uses a polypropylene cone, hi-roll rubber surround, 2-inch voice coil, and stamped-steel frame. Its outside diameter is 12-1/8 inches, with an 11-inch cutout requirement and a 5-15/16-inch mounting depth. These dimensions should be checked against the enclosure baffle and available mounting clearance before installation.

For a sealed build, Infinity specifies 1.4 cubic feet including driver displacement; for a ported build, it specifies 1.6 cubic feet including driver and port displacement, tuned to 34 Hz with a 2.95-inch-diameter, 4-inch-long port. Connect the subwoofer to an amplifier using bare or tinned wire, with 14 AWG to 8 AWG wire recommended according to cable length. Use a low-pass crossover and verify polarity, enclosure sealing, and amplifier gain settings during setup.