Rockford Fosgate R2-500X4

$330.00

Prime Series 4-channel car amplifier — 75 watts RMS x 4

About the Rockford Fosgate R2-500X4

Give your speakers the power they deserve

Rockford Fosgate’s Prime Series R2-500X4 amplifier can power four speakers with 75 watts RMS each, so you’ll hear your music loud and clear over the noises of the wind and road. You could also use this amp in bridged, 2-channel mode to power a couple of subwoofers with 250 watts RMS each. High- and low-pass filters help you get maximum performance from the speakers in your vehicle.

Setting it up for optimum performance

Rockford Fosgate’s C.L.E.A.N. technology (Calibrated Level Eliminates Audible Noise) setup system ensures your music will sound as clean and powerful as possible. It’s a simple system to use — turn it up until the light shows red, then turn it down until the red light goes out. Speaker-level inputs let you hook this amp up to almost any system, even a factory stereo.

Product highlights:
Featured in our article: Best 4-channel car amplifiers for 2025
4-channel car amplifier
75 watts RMS x 4 at 4 ohms
125 watts RMS x 4 at 2 ohms
250 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)

CTA-2006 compliant
Class-D amplifier design
variable high- and low-pass filters (50-250 Hz, 12 dB/octave) on front and rear channels

More Info:
C.L.E.A.N. gain setup system includes clip lights
auto remote turn-on
preamp and speaker-level inputs
preamp outputs
wiring, fuse, and hardware not included with amplifier
4-gauge power and ground leads and an 80-amp fuse recommended

dimensions: 10-1/16″W x 2″H x 7.75″D
warranty: 1 year

What’s in the box:

4-Channel amplifier
Two 7″ Speaker input harnesses
3mm Allen Hex key
Four 3/4″ Screws
4 Flat washers
Installation and Operation instructions (English/ French/ Spanish/ German/ Italian)
Certificate of Performance
Rockford Fosgate contact information

More details on the Rockford Fosgate R2-500X4

Features & specs

Performance
RMS Power Output (Watts x Channels)	75 x 4
Peak Power Output (Watts x Channels)	N/A
Power at 2 Ohms (Watts x Channels)	125 x 4
Power at 1 Ohm (Watts x Channels)	—
Bridged Power (Watts x Channels)	250 x 2
Minimum Impedance Bridged	4
Minimum Impedance Unbridged	2
Best Frequency Response	20-20k Hz
THD at Rated RMS Power	1%
Signal to Noise Ratio	80 dB
Input Voltage	14.4v
Features
Amplifier Class	D
Built-in DSP	No
Remote Control	No
Low-Pass Crossover Frequency	50-250 Hz
Low-Pass Slope (dB/octave)	12 dB/octave
High-Pass Crossover Frequency	50-250 Hz
High-Pass Slope (dB/octave)	12 dB/octave
Bass Boost	No
Bass Boost Frequency	N/A
Fan Cooled	No
Fuse Rating	80
Speaker Level Inputs	Yes
Preamp Outputs	2
Width (inches)	10-1/16
Height (inches)	2
Depth (inches)	7-3/4
Parts Warranty	1 Year
Labor Warranty	1 Year

The Rockford Fosgate R2-500X4 replaces these items:

Rockford Fosgate Prime R400-4D

Features

Overview: The Rockford Fosgate Prime R2-500X4 is a 4-channel full-range Class D amplifier. It’s effectively two full range 2-channel amps built into one chassis, labeled Front and Rear. Each section of the amp is bridgeable, so it can be wired as 4-channel, 3-channel, or 2-channel.

CEA-2006 Compliant: CEA-2006 is a system of testing and measurement for mobile audio amplifiers. This voluntary standard advocates a uniform method for measuring an amplifier’s RMS power output and signal-to-noise ratio. The criteria for measuring amplifier power uses a DC input voltage of 14.4 volts and the RMS power output is measured over a frequency range of 20 Hz to 20 kHz (for full range amplifiers), with 1% or less Total Harmonic Distortion plus noise (THD+N). Signal-to-Noise ratio is measured in weighted absolute decibels (dBA) at a reference of 1 watt into 4 ohms. CEA-2006 standards allow consumers to compare car amplifiers and receivers under the same conditions (apples to apples).

CEA-2006 Specifications:

Power Output: 75 watts RMS x 4 into 4Ω
Signal to Noise Ratio: >80 dBA (measured at 1 watt into 4Ω)

Other Specifications:

Power Output:
- 2Ω: 125 watts RMS x 4 (14.4 volts)
- Bridged: 250 watts RMS x 2 (14.4 volts, 4Ω)

Mounting: The amplifier can be mounted vertically, horizontally, or inverted using the supplied mounting screws; horizontal mounting (right side up) will provide the best cooling.

Controls

Input Switch: Set this switch to match the number of inputs used, 2-channel or 4-channel. In 2-channel mode the signal on the front input feeds all four output channels.

Independent Controls: The R2-500X4 has independent, top-mounted controls for the front and rear channels:

Gain: rotary gain controls; labeled 0 to 11 (equivalent to 150mV-4V line level or 450mV-12V speaker level)
Crossover: 3-position switch; choose low-pass, all-pass, or high-pass; low-pass and high-pass crossovers are 12 dB per octave Butterworth
Frequency: rotary dials; continuously variable from 50-250 Hz

Auto Turn-on Switch: When using speaker level inputs, this switch can be set to On and the amp will turn on when it senses an input signal (DC offset on the left front input). When using the RCA inputs a remote turn-on wire must be connected.

Connections

Power Terminals: The power and ground terminals are nickel-plated set-screw terminals, and will accommodate up to 4-gauge wire. (Rockford Fosgate recommends using 4-gauge power and ground wire.) The set screws are tightened/loosened with the included 3mm hex key.

Fuses: The amplifier does not have on-board fuses. An 80-amp fuse should be placed on the power wire within 18″ of the battery.

Remote Turn-On Terminal: The remote turn-on terminal is a nickel-plated set-screw terminal that will accommodate up to 8-gauge wire. The set screw is tightened/loosened with the included 3mm hex key.

Speaker Terminals: The speaker terminals are nickel-plated set-screw terminals that will accommodate up to 8-gauge wire. The set screws are tightened/loosened with the included 3mm hex key.

RCA Input Jacks: There are two pair of RCA input jacks for the front and rear channels. The balanced differential inputs are nickel-plated to resist signal degradation caused by corrosion.

RCA Pass-Thru Jacks: One pair of nickel-plated RCA pass-thru jacks provide a convenient way to connect an additional amplifier without running an extra set of RCA cables from the front of the vehicle to the amplifier location. The signal from the front RCA inputs is passed to the RCA outputs.

Speaker Level Inputs: There are ports for the two included speaker input harnesses, front and rear. If speaker level inputs are used, nothing should be connected to the RCA jacks.