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Rockford Fosgate R250X4

Prime Series 4-channel car amplifier — 40 watts RMS x 4

10 Reviews | 5 questions - 14 answers


Our take on the Rockford Fosgate R250X4

Rockford Fosgate performance in a small package. The Prime Series R250X4 4-channel amp can drive your speakers with 40 watts RMS each, so you'll really feel your tunes rockin'. Or, you could switch the R250X4 to 2-channel mode to run a couple of subs with 125 watts RMS each — when you buy a bigger amp for your subs later on, you can still use this 4-channel to drive all your speakers. Smart move.

Rockford Fosgate power for your speakers

Rockford Fosgate performance in a small package. The Prime Series R250X4 4-channel amp can drive your speakers with 40 watts RMS each, so you'll really feel your tunes rockin'. Or, you could switch the R250X4 to 2-channel mode to run a couple of subs with 125 watts RMS each — when you buy a bigger amp for your subs later on, you can still use this 4-channel to drive all your speakers. Smart move.

You can use the high- and low-pass filters and Rockford Fosgate's famous Punch boost to get maximum performance from the speakers in your vehicle. And speaker-level inputs let you hook this amp up to almost any system, even a factory stereo.

Rugged performance and value

The R250X4's heavy cast-aluminum chassis efficiently draws damaging heat away from its internal components, ensuring reliable, long-term play. The amp's built-in sensors keep track of the output current and power supply temperature, ensuring that plunging speaker impedances (they change constantly during play) or even a short circuit won't hurt anything. Your driver's seat will become your favorite place for listening to music once this Prime amp goes to work.

Product Highlights:

  • 4-channel car amplifier
  • 40 watts RMS x 4 at 4 ohms (60 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
  • variable high- and low-pass filters (50-250 Hz, 12 dB/octave) on front and rear channels
  • selectable bass boost (0, 6, 12 dB at 45 Hz)
  • Class-AB amplifier design
  • MOSFET power supply
  • frequency response: 20-20K Hz
  • preamp and speaker-level inputs
  • 8-gauge power and ground leads and a 50-amp fuse recommended — wiring and hardware not included with amplifier
  • no onboard fuses — when installing multiple amps in a system, an additional 50-amp in-line fuse between the distribution block and this amplifier is recommended
  • 11-1/4"W x 2"H x 7-3/8"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

What's in the Box:

  • 4-Channel amplifier
  • Two 6" Speaker level input harnesses
  • 3mm Allen wrench
  • Four 3/4" Self-tapping screws
  • 4 Flat washers
  • Installation & Operation manual (English/ French/ Spanish/ German/ Italian)
  • Amplifier verification certificate

1 week in my Mustang and the bass sound is superb!

Manuel Guerrero, Missouri City, TX


Rockford Fosgate R250X4 Reviews

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(10 Reviews)
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Hands-on research

Product Research



Overview: The front and rear sections of the Rockford Fosgate Prime R250X4 4-channel amplifier are bridgeable, so it can be wired in 4-channel, 3-channel, or 2-channel mode.

CEA 2006 Compliant: The R250X4's power ratings and signal to noise ratio are measured according to the uniform standards advocated by the Consumer Electronics Association (CEA). This allows you to accurately compare these specifications for all CEA 2006-compliant amplifiers, even from different brands. Manufacturers who adhere to these standards can display the CEA 2006 logo on their products and packaging. CEA2006 Specifications for this amplifier are:

  • 4 Ohms: 40 watts RMS x 4 at 4 ohms, 14.4 volts, and less than 1% THD+N
  • 2 Ohms: 60 watts RMS x 4 at 2 ohms, 14.4 volts, and less than 1% THD+N
  • Bridged: 125 watts RMS x 2 at 4 ohms, 14.4 volts, and less than 1% THD+N
  • S/N: 80 dB, measured at 1 watt output (100 dB measured at rated power)

LED Indicator: The amplifier is equipped with an LED power/protect indicator. The LED illuminates blue when the unit is turned on. It illuminates red if the thermal or short circuit protection circuit is engaged, and the amplifier will automatically turn off.

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 front and rear amplifier channels have independent gain controls. Each rotary control is labeled 1 to 11 and has a sensitivity range of 150mV to 4V when using the RCA inputs, 450mV to 12V when using the speaker level inputs.

Crossover: There are also independent 12 dB/octave crossovers for the front and rear channels. Crossover switches allow you to choose low-pass, high-pass, or full-range operation. The crossover points are continuously variable from 50 to 250 Hz.

Punch EQ: The Punch EQ bass boost circuits are individually selectable, 0 (flat), +6 dB, or +12 dB and centered at 45 Hz.

Input Switch:

  • 2-CH: when using only the front inputs
  • 4-CH: when using the front and rear inputs


Power Terminals: The power and ground terminals are nickel-plated set screw terminals and will accommodate up to 4 gauge power and ground wires.

Fuse: An external 50-amp fuse (not included) must be installed on the power wire at the battery. If a wiring kit is used which includes a fuse with a value other than 50-amps, the original should be replaced with a 50-amp fuse.

Remote Terminal: The remote turn-on terminal is a nickel-plated set screw terminal that will accommodate up to an 8 AWG wire. It's used to remotely turn the amplifier on and off.

Speaker Terminals: The four pair of speaker outputs are nickel-plated set screw terminals what will accommodate up to 8 AWG speaker wire.

RCA Input Jacks: Front and rear RCA input jacks provide an easy connection for preamp level input. They are nickel-plated to resist signal degradation caused by corrosion.

Speaker Level Input: Two speaker level input harnesses are included, making it easier to add the amplifier to a factory radio or to a receiver with no preamp outputs.

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Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

always a fan of good quality like Rockford Fosgate [ Christopher  Jul 14, 2018 ]
advisor recommendation for the vehicle i am working on. [ DONALD  Feb 28, 2018 ]
to power front speakers and mid-bass speakers. [ MICHAEL  Aug 22, 2017 ]
Awesome mids amp perfect power to match pro 6.5' mids i have 1-amp per 2-door but awesome quality [ michael  Apr 23, 2017 ]
Because Rockford Fosgate is awesome equipment. Never gone wrong with anything of theirs before. [ BENJAMIN KEITH  Jul 15, 2016 ]
Rockford Fosgate amps are where it is at. Great product that will run forever [ PAUL D  Jun 22, 2016 ]

5 questions already asked

Yes. I had to turn the gain done. Very nice amp for the $ [ Kevin  Mar 15, 2018 ]
Yes. Quite nicely. I am really happy with my purchase! [ Howard  Mar 14, 2018 ]
This amp will easily power those speakers. Mine is powering a pair of co-ax speakers in the doors of my car and a pair of eight inch mid-bass speakers in the rear and does it effortlessly. [ MICHAEL  Mar 14, 2018 ]
Yes [ mike  Mar 14, 2018 ]
I am powering 4 kickers with ease. [ Jerald  Mar 14, 2018 ]
Was too big for my space. Sent it back. [ RICARDO  Mar 14, 2018 ]
More information on this would be helpful: 1. What is the wattage rating of the speakers? 2. What is the ohm rating of the speakers (8, 4, 2) ? 3. When you say 2-way, are you talking about dual voice coils (it will have two separate sets of lead connectors) or dual drivers (one set of lead connectors and two speaker "cones")? By my calculations, (2) two-way speakers is only a total of four drivers, not 8. If you're researching the idea of buying two of these amplifiers to power that "total" of 8 speakers, questions #1-#3 above will really need to be answered above before any final wattage/ohm rating can be calculated in terms of what level of resistance (measured in ohms) would be seen at the amplifier. This will need to be determined before knowing what power handling rating your speakers have and whether or not the amplifier can be used to push them effectively. Underpowering speakers is just as bad as overpowering them. I know this doesn't help too much at this point, but if you can give the details provided in the questions above, then your questions can be answered precisely. Better yet, what's the brand/model of the speakers and how many do you have total? [ Tobias  Sep 25, 2015 ]
If you are looking for something to give you a lot of bass for the sub this is not the one for you, but if you are looking for it to give you deep rich continuous sound from all connected speakers this is definitely it. [ Jorge  Feb 02, 2015 ]
No it's a great amp but it is made for mids or two smaller subs like 10s or 8s [ Chris  Feb 02, 2015 ]
I mounted in in the saddle bag of a motorcycle and still has plenty of room to spare id say youd be fine [ jarrett  Dec 08, 2014 ]
It fits under my tacoma seat with plenty i room to spare [ Chris  Dec 07, 2014 ]
It will fit if you don't have power seats. The manual seats have plenty of room [ Jorge  Dec 07, 2014 ]
With no problem just not 1 ohm stable and its bridgable [ jarrett  Jul 08, 2014 ]
Thanks for your question. For information on selecting the best amp for your subs I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system. [ Greg  Jul 08, 2014 ]  Staff

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