Rockford Fosgate T1D215 Power 15" Dual 2-Ohm Subwoofer

The Rockford Fosgate T1D215 is a 15-inch Power Series subwoofer designed for vehicle systems that need substantial low-frequency output from a single driver. Its dual 2-ohm voice-coil design provides wiring flexibility for matching a compatible mono or multi-channel amplifier. It is intended for a properly designed sealed or vented enclosure rather than direct installation into a factory speaker location.

With a 1,000-watt RMS power rating and 2,000-watt maximum rating, the T1D215 is suited to systems built around a dedicated subwoofer amplifier. Its 26.3 Hz free-air resonance and 16.4 mm one-way Xmax support deep-bass playback when it is installed in an enclosure built to the published recommendations. The 88 dB sensitivity specification helps describe its output potential with appropriate amplifier power and enclosure design.

This model uses dual 2-ohm voice coils and Rockford Fosgate's SWIFT terminal system, which uses a removable jumper to configure the coils in series or parallel. That arrangement allows the subwoofer to present a nominal 4-ohm or 1-ohm load, depending on the jumper configuration. Amplifier selection should always account for its rated power capability and minimum stable impedance.

The T1D215 combines a die-cast aluminum basket with a Kevlar-paper composite cone, Santoprene surround, aluminum dust cap, dual Nomex spiders, and dual magnets. These components are designed to support cone control and durability during high-excursion operation. The 3-inch aluminum voice-coil former is paired with a 3-inch voice-coil diameter.

For a system upgrade, the T1D215 can be used in either a sealed enclosure for a compact, controlled installation or a vented enclosure for greater output around the box tuning frequency. Rockford Fosgate publishes enclosure guidance for both approaches, including a 2.25-cubic-foot sealed volume and a 2.66-cubic-foot vented volume. A dedicated low-pass crossover and an appropriately configured amplifier are recommended to integrate it with full-range speakers.

Key Features

• 15-Inch Power Series Driver: Provides a large cone area for dedicated low-frequency reproduction.
• Dual 2-Ohm Voice Coils: Supports series or parallel wiring for compatible amplifier loads.
• 1,000-Watt RMS Rating: Matches high-power subwoofer amplifier applications when set up correctly.
• 16.4 mm Xmax: Allows substantial linear cone travel for bass playback.
• SWIFT Terminal System: Uses a removable jumper for convenient impedance configuration.
• Die-Cast Aluminum Basket: Provides a rigid foundation for the moving assembly.

Design & Installation

The T1D215 uses a rigid die-cast aluminum basket, Kevlar-paper composite cone, Santoprene surround, aluminum dust cap, dual Nomex spiders, and dual 110-ounce magnets. Its aluminum voice-coil former and 3-inch voice coil are part of a design intended for high-power subwoofer use. A trim ring, mounting hardware, driver bit, and installation manual are included with the product.

Plan for a 13-15/16-inch mounting cutout and 8-25/64-inch mounting depth, plus sufficient enclosure volume and clearance behind the motor. Rockford Fosgate lists a 2.25-cubic-foot sealed enclosure or a 2.66-cubic-foot vented enclosure with one 4-inch by 10-inch port as reference designs. Use the SWIFT terminal jumper only as directed, match the final impedance to an amplifier that is stable at that load, and use an active 80-100 Hz low-pass crossover at 12 dB per octave as recommended in the manual.