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Power for your music that'll fit almost anywhere

The Prime Series R250-4 4-channel amp gives you Rockford Fosgate performance in a compact package, driving each of your four speakers with 40 watts RMS. You can also bridge this workhorse amp into 2-channel mode to deliver 125 watts RMS each to a pair of components or subs. The built-in frequency filters and Rockford Fosgate's famous Punch bass boost allow you to adjust the amp to work best with your speaker setup and your vehicle.

R250-4 control panel

Performance and value

Rockford Fosgate designed Prime amps to deliver Power Output Without Excessive Regulation (POWER), which means they'll respond quickly to the peak demands that you may throw at your system. Your driver's seat will become your favorite place for listening once this compact Prime amp goes to work.

Product Highlights:

  • 4-channel car amplifier
  • 40 watts RMS x 4 at 4 ohms (65 watts RMS x 4 at 2 ohms)
  • 125 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)
  • CEA-2006 compliant
  • high-pass filter (80 Hz, 12 dB/octave)
  • variable low-pass filter (50-250 Hz, 12 dB/octave)
  • switchable bass boost (0, 6, 12 dB at 45 Hz)
  • Class-AB amplifier design
  • MOSFET power and output stages
  • frequency response: 20-20K Hz
  • preamp inputs and outputs
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • fuse rating: 25A x 2
  • 12-1/8"W x 2-1/2"H x 7-11/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Rockford Fosgate Prime R250-4 Reviews

Average Customer Review:

1 Review

Great Little Amp

Written by: Jetboy from Kennesaw, GA on October 6, 2012

I want to start this review by saying that I screwed up and did not get this from Crutchfield. I thought I saved some $$ by getting it elsewhere. I may have saved a few bucks, but I got absolutely no support from the seller. Sorry Crutchfield won't make the same mistake again. My other equipment has come from Crutchfield and the support is second to none. Now for the amp, This Rockford Fosgate Prime R250-4 kicks butt. Rockford Fosgate has the reputation for great amps and this is no exception. First off is its size, its compact with is nice if you wish to install it in a tight area or don't want a huge footprint. Second: the sound is awesome, it has added clarity to my music and makes my speakers rock. It's rated at 250watts, but Rockford tests all there amps before shipping and mine was rated at 322 watts. I like the fact it ca be installed in almost any position vertical and even mounted upside down on a rear deck and Rockford says its ok, a real plus. I would highly recommend this amp, for the price it can't be beat!

Pros: Great value for the money. Solid Amp

Cons: none so far

Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel amplifier with two 20A ATC fuses installed
  • 2 Spare 20A ATC fuse
  • Four 4mm x 20mm self-tapping screws
  • 4 Flat washers
  • Installation & Operation manual

Product Research



Overview: The Rockford Fosgate Prime R250-4 4-channel amplifier is designed to power two pairs of full-range or component speakers in 4-channel mode, two subwoofers in bridged 2-channel mode, or two full-range speakers and a single subwoofer in 3-channel mode.

CEA 2006 Compliant: The Rockford Fosgate Prime R250-4's power ratings are measured according to standards provided by the Consumer Electronics Association (CEA). These standards allow you to accurately compare the rated power output of all CEA 2006-compliant amplifiers, even if they come from different brands. Manufacturers who adhere to the standards can display the CEA 2006 logo on their products and packaging. CEA2006 Specifications for this amplifier are:

  • Four-Channel: 40 watts RMS x 4 at 4 ohms, 14.4 V, and 1% THD+N (65 watts x 4 at 2 ohms, 14.4 V, and 1% THD+N)
  • Two-Channel Bridged: 125 Watts x 2 at 4 ohms, 14.4 V, and 1% THD+N

LED Indicators: The Rockford Fosgate amplifier is equipped with two side-mounted LED indicators.

  • Power LED: illuminates blue when the unit is turned on.
  • Protect LED: illuminates red if a short circuit or too low of an impedance is detected at the speaker connections. The amplifier will automatically shut down if this occurs.

Mounting: The amplifier can be mounted vertically or horizontally using the supplied mounting screws. The amplifier should never be mounted in an engine compartment as this will void the warranty.


Gain Controls: The R250-4 is equipped with independent gain controls for the front and rear channels. The amplifier's gain controls are preset to match the output of most source units. The gain controls can be adjusted from 1 to 11 with an input sensitivity range of 150mV to 8V.

Crossovers: The amplifier is equipped with independent 12dB/octave Butterworth crossovers for the front and rear channels. The Crossover Switches allows you to select from the following:

  • All-Pass (full-range): The all-pass setting allows all frequencies (20-20kHz) to pass through the amplifier from your connected headunit to your speakers.
  • High-Pass: The high-pass setting is fixed and allows only frequencies above 80Hz to pass through the amplifier to your speakers.
  • Low-Pass: The low-pass setting is variable and allows only frequencies below 50-250Hz to pass through the amplifier to your speakers.

Punch Bass: The Punch bass controls for the front and rear channels can be set to 0dB, +6dB, +12dB at a fixed 45Hz.


Power Terminals: The power and ground terminals are nickel-plated screw terminals and will accommodate up to 4 AWG power/ground wire (up to 1/2" spade or ring-style connector).

Note: Based on the 40A fuse rating and the power output of the amplifier, an 8-gauge amplifier wiring kit is recommended.

Remote Turn-On Terminal: The remote turn-on terminal is a nickel-plated screw terminal that will accommodate up to an 8 AWG wire (up 3/8" spade or ring-style connector). This terminal is used to remotely turn-on and turn-off the amplifier when +12V DC is applied, when connected to your head unit's remote turn-on lead.

Speaker Terminals: The eight speaker terminals (front left +/-, rear left +/-, front right +/-, and rear right +/-) are heavy duty, nickel-plated screw-terminals what will accommodate up to 8 AWG speaker wire (up to 3/8" spade or ring-style connectors).

RCA Input Jacks: The industry standard RCA jacks provide an easy connection for signal level input. They are nickel-plated to resist signal degradation caused by corrosion. There are 4 RCA input jacks for front left/right and rear left/right channels.

Fuses: The amplifier is equipped with two installed 20-amp ATC fuses. The amplifier also comes supplied with two spare 20-amp fuses.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.