Rockford Fosgate P2D4-15 15" Dual 4-Ohm Subwoofer

The Rockford Fosgate P2D4-15 is a 15-inch dual voice coil subwoofer designed for vehicle audio systems that need substantial low-frequency output without moving to a competition-focused driver. Its dual 4-ohm voice coils provide wiring flexibility for matching a compatible mono or multi-channel amplifier. With a 400-watt RMS rating, it is intended for systems built around sustained bass performance rather than peak-power claims.

This Punch P2 model suits listeners who want deeper bass extension and strong impact from a large-format subwoofer. Its 15-inch cone area helps it move substantial air, making it a practical choice for larger sealed or ported enclosures. The published sensitivity is 86 dB at 1 watt/1 meter, and its resonance frequency is 20.9 Hz.

A Kevlar-reinforced paper-pulp cone combines rigidity with the character of a paper-based cone, while the tall-profile VAST Santoprene surround supports cone travel. The subwoofer uses a high-temperature 2.25-inch voice coil with a Nomex reinforcement collar. Its dual spider assembly and integrated spider venting are designed to support coil cooling and long-term mechanical control.

The P2D4-15 uses an extended pole piece and bumped, vented backplate as part of its motor structure. A stamped compound-bend steel basket provides the mounting foundation, while flexible tinsel leads are stitched to reduce strain during cone movement. The design also includes a removable protective PVC motor cover and a diamond-cut cast aluminum trim ring.

For installation, Rockford Fosgate specifies both sealed and vented enclosure alignments for this model. A sealed enclosure is suited to a compact, controlled system approach, while the recommended vented enclosure is tuned for lower extension. Pair it with an amplifier that can deliver appropriate continuous power at the final impedance created by the selected voice-coil wiring configuration.

Key Features

• 15-Inch Driver: Large cone area supports substantial low-frequency air movement.
• 400-Watt RMS Rating: Matches amplifiers designed for sustained 400-watt output.
• Dual 4-Ohm Voice Coils: Allows wiring choices to suit compatible amplifiers.
• Kevlar-Reinforced Paper Cone: Provides a rigid, lightweight cone structure.
• Spider Venting Design: Helps promote voice-coil cooling during operation.
• Sealed Or Ported Ready: Supports manufacturer-published enclosure alignments.

Design & Installation

The P2D4-15 is built around a stamped 16-gauge compound-bend frame, an extended-pole motor assembly, and a bumped vented backplate. Its mechanical package includes a Kevlar-reinforced paper-pulp cone, tall-profile Santoprene surround, dual poly-cotton spiders, aluminum voice-coil former, protective PVC motor cover, and cast aluminum trim ring. Custom 10-AWG nickel-plated push terminals provide the speaker connection points.

Allow for a 13.9-inch mounting cutout and 7.34 inches of mounting depth before selecting an enclosure. Rockford Fosgate lists a 1.58-cubic-foot sealed enclosure and a 2.66-cubic-foot vented enclosure as recommended alignments; enclosure volume is gross internal volume before speaker and port displacement. Because this is a dual 4-ohm voice-coil subwoofer, confirm the amplifier's stable impedance range and wire the coils accordingly before final installation.