Rockford Fosgate P500X1BD 500W Mono Subwoofer Amplifier

The Rockford Fosgate P500X1BD is a mono car amplifier designed specifically to power subwoofers. It provides a focused bass channel for systems where a factory or aftermarket receiver needs more low-frequency output. With stable operation down to a 1-ohm load, it supports several common subwoofer wiring configurations.

This amplifier is intended for listeners building a dedicated subwoofer stage rather than powering full-range speakers. Its Class-BD circuit topology is engineered for efficient low-frequency amplification, helping it deliver substantial continuous power in a compact full-chassis format. Output is rated at 150 watts RMS at 4 ohms, 300 watts RMS at 2 ohms, or 500 watts RMS at 1 ohm.

The P500X1BD has a bass-focused operating range of 20 Hz to 250 Hz and includes a variable low-pass crossover for blending a subwoofer with door speakers or component systems. A fixed 28 Hz infrasonic filter helps limit very low-frequency content sent to the woofer. This can be especially useful when the amplifier is paired with a vented subwoofer enclosure.

Its RCA inputs accept either low-level RCA signals or high-level speaker signals, allowing integration with many factory and aftermarket source units. High-level input use activates the amplifier's auto turn-on feature, reducing the need for a separate signal converter in compatible installations. RCA pass-through outputs provide a way to feed signal to additional amplifiers in a multi-amp system.

Rockford Fosgate's C.L.E.A.N. setup system uses input and output clip indicators to assist with level matching during installation. The onboard Punch EQ provides adjustable bass boost at 45 Hz, while an optional remote Punch Level Control can place subwoofer level adjustment within reach of the driver. The P500X1BD is a practical choice for matching a properly wired subwoofer system to a 150- to 500-watt RMS mono amplifier channel.

Key Features

• 500W RMS at 1 Ohm: Supplies continuous mono power for compatible 1-ohm subwoofer loads.
• Class-BD Topology: Efficient bass-oriented amplification helps manage power use and heat.
• High- and Low-Level Inputs: Connects to factory speaker wiring or RCA-equipped receivers.
• C.L.E.A.N. Setup: Input and output clip indicators assist with gain adjustment.
• Punch EQ: Adds adjustable bass boost from 0 to +18 dB at 45 Hz.
• RCA Pass-Through: Sends the input signal onward to additional compatible amplifiers.

Design & Installation

The P500X1BD uses a full-size chassis measuring 2.38 by 7.76 by 11.03 inches and has a convection-cooled design. Nickel-plated captive C-clamp speaker terminals accept 8 AWG speaker wire, while the power and ground terminals accept 4 AWG cable. Status and setup indicators include power, protect, thermal, input clip, and output clip monitoring.

Use this mono amplifier with subwoofers wired for a final impedance of 1, 2, or 4 ohms; do not use a load below 1 ohm. Installation requires appropriate power and ground wiring, an 80-amp inline fuse installed near the battery, source wiring, and a solid chassis ground. Leave at least 1 inch of air space around the heatsink for cooling, and use the low-pass crossover, infrasonic filter, and gain setup controls to match the amplifier to the enclosure and subwoofer system.