Rockford Fosgate R2-500X4 4-Channel Amplifier

The Rockford Fosgate Prime R2-500X4 is a full-range, four-channel car amplifier designed to add dedicated power to an upgraded speaker system. It delivers 75 watts RMS to each of four channels at 4 ohms, giving compatible door, dash, or rear-deck speakers more headroom than most factory-radio power. Its compact chassis is suited to installations where available mounting space is limited.

This amplifier is a practical choice for listeners building a clearer, more controlled full-range system without adding a separate amplifier for every speaker pair. It can run four speakers in stereo at either 4 or 2 ohms, or it can be bridged into two channels for higher-output applications. Variable high-pass and low-pass crossovers help direct the appropriate frequency range to the speakers connected to each channel pair.

The R2-500X4 uses full-range Class-D amplifier topology, which is designed for efficient operation in a vehicle electrical system. Its rated output is 125 watts RMS per channel at 2 ohms, while bridged operation provides 250 watts RMS per channel into 4-ohm loads. A 20 Hz to 20 kHz frequency response supports use with speakers across the normal audible range.

Rockford Fosgate C.L.E.A.N. setup circuitry uses input and output clip indicators to assist with gain adjustment. Balanced differential inputs are intended to reduce noise picked up by signal cables, while RCA pass-through outputs can feed an additional amplifier. The amplifier also supports both low-level RCA and high-level speaker inputs for integration with many aftermarket or factory audio systems.

For a staged system, the R2-500X4 can power front and rear speakers while a separate mono amplifier handles a subwoofer. Its 2/4-channel input selector can simplify signal routing when the source unit has fewer than four output channels. Top-mounted controls, separate front and rear gain adjustment, and independently adjustable front and rear crossover sections help make system tuning more accessible after installation.

Key Features

• Four-Channel RMS Power: Delivers 75 watts RMS x 4 at 4 ohms or 125 watts RMS x 4 at 2 ohms.
• Bridged Capability: Combines channel pairs for 250 watts RMS x 2 into 4-ohm loads.
• Full-Range Class-D Design: Provides efficient amplification for component, coaxial, and other full-range speakers.
• C.L.E.A.N. Setup Circuitry: Clip indicators assist with setting gain levels for a cleaner signal path.
• Variable Butterworth Crossovers: Front and rear high-pass or low-pass filters adjust from 50 Hz to 250 Hz.
• High- and Low-Level Inputs: Supports RCA connections or speaker-level signals from compatible factory systems.

Design & Installation

The R2-500X4 uses a cast aluminum heat sink with convection cooling and Rockford Fosgate's MEHSA4 heat-sink application. Its compact 1.9-inch-high chassis measures 6.8 inches wide by 10.1 inches deep. Top-mounted controls and compression terminal blocks keep adjustment and connection points accessible when the amplifier is mounted appropriately.

Use 4 AWG power wiring and an externally mounted 80-amp fuse as specified for the amplifier. The amp supports 4-ohm or 2-ohm stereo speaker loads, while bridged channels require a 4-ohm load; consult the owner’s manual for the correct bridged speaker-terminal connections. For best results, set crossover points and front/rear gains after the amplifier is wired, then use the C.L.E.A.N. indicators to avoid clipping.