Rockford Fosgate P1-S4-12 12" 4-Ohm SVC Subwoofer

The Rockford Fosgate P1-S4-12 is a 12-inch single-voice-coil subwoofer designed to add dedicated low-frequency output to a car or truck audio system. Its 4-ohm impedance and 250-watt RMS power rating make it suited to a properly matched mono or subwoofer amplifier. It is intended for listeners who want more bass extension and impact than factory full-range speakers can provide.

This Punch P1 model uses a Kevlar-reinforced paper-pulp cone paired with a high-density NBR rubber surround. That combination is designed to maintain cone control while supporting the excursion needed for bass reproduction. With an 86 dB sensitivity rating and 25 Hz free-air resonance, it is built for low-frequency duty rather than full-range playback.

A 2-inch high-temperature, four-layer voice coil is used for thermal durability under sustained power. The coil includes a spun-laced Nomex insulating reinforcement collar, while the vented motor design and spider-plateau cooling help manage heat around the voice coil. Stitched flexible lead wires and a tear-resistant poly-cotton spider support repeated cone movement.

The P1-S4-12 can be installed in either a sealed or vented enclosure, allowing the system to be tailored for available space and desired bass character. A 1.02-cubic-foot sealed enclosure is the specified compact option, while the 1.79-cubic-foot vented alignment is tuned for deeper extension. Its single 4-ohm coil should be considered when selecting an amplifier and planning the final system impedance.

This subwoofer is a practical fit for a custom enclosure or as a replacement driver in a compatible 12-inch subwoofer system. The 6.0-inch mounting depth and 11.22-inch cutout requirement should be checked against the enclosure before purchase. A soft-touch trim ring accommodates an optional integrated grille for installations where cone protection is needed.

Key Features

• 250W RMS Power Handling: Supports amplifier matching for continuous subwoofer output.
• Single 4-Ohm Voice Coil: Provides a straightforward 4-ohm load for a compatible amplifier channel.
• Kevlar-Reinforced Paper Cone: Combines paper-pulp bass character with reinforced cone construction.
• 2-Inch High-Temperature Voice Coil: Helps the driver manage heat during sustained listening.
• Spider Venting Design: Promotes airflow around the voice-coil area for cooling.
• Sealed Or Vented Compatibility: Allows enclosure selection based on space and bass goals.

Design & Installation

The P1-S4-12 uses a heavy-gauge stamped-steel frame with 16-gauge compound-bend geometry, an extended pole piece, and a bumped vented backplate. Its motor is protected by a removable semi-flexible PVC cover, and the woofer uses all-metal radially oriented compression terminals. The high-density NBR surround, poly-cotton spider, and multi-point neck-joint bonding are designed to support durable operation.

Plan for an 11.22-inch cutout and 6.0 inches of mounting depth, with additional clearance behind the motor as needed. Use a sealed enclosure of 1.02 cubic feet for the listed sealed alignment, or a 1.79-cubic-foot vented enclosure with the specified port dimensions for the listed vented alignment. Connect the single 4-ohm coil to an amplifier selected and configured for a 4-ohm subwoofer load; the compression terminals accept up to 10-AWG speaker wire.