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Rockford Fosgate Prime R300X4

4-channel car amplifier — 50 watts RMS x 4

11 Reviews | 4 questions - 6 answers

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Rockford Fosgate Prime R300X4

Overview

Our take on the Rockford Fosgate Prime R300X4

Rockford Fosgate performance in a small package. The Prime Series R300X4 4-channel amp can drive your speakers with 50 watts RMS each, so you'll really feel your tunes rockin'. Or, you could switch the R300X4 to 2-channel mode to run a couple of subs with 150 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 R300X4 4-channel amp can drive your speakers with 50 watts RMS each, so you'll really feel your tunes rockin'. Or, you could switch the R300X4 to 2-channel mode to run a couple of subs with 150 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 R300X4'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.

I've alway used Rockford amps and this one rocks! Coupled with a set of Polk speakers my jeeps sound is where it needs to be for someone that has his top off 9 months out of the year.

John D., Corpus Christi, TX

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

Product Highlights:

  • 4-channel car amplifier
  • 50 watts RMS x 4 at 4 ohms (75 watts RMS x 4 at 2 ohms)
  • 150 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
  • 13-1/4"W x 2"H x 7-3/8"D
  • warranty: 1 year
  • Our 60-day money-back guarantee
Reviews

Rockford Fosgate Prime R300X4 Reviews

Average Customer Review:

11 Reviews

Great amp

Written by: John D. from Corpus Christi, TX on June 20, 2016

Crutchfield Customer Review (What's this?)

I've alway used Rockford amps and this one rocks! Coupled with a set of Polk speakers my jeeps sound is where it needs to be for someone that has his top off 9 months out of the year.

Pros: Great bang for you buck. Quality amp from Rockford

Cons: None

Nice Amp

Written by: MikeV530 from Philadelphia, PA on April 22, 2016

Crutchfield Customer Review (What's this?)

Great amp!!! Awesome price!!

Pros: Quality, price

Cons: None so far

Excellent Sound Rediculously LOUD!!!

Written by: Audiology from NY on April 16, 2016

Rated almost 400 watts. Sound is excellent for an entry level unit. I never hear systems that run anywhere near as loud as this. Subs yes, but not everything else. Pushes my Sony 6 x 9 speakers almost like subs. I wouldn't trade my Sony speakers for Polks if they were free. In fact, I'd throw them out and get more 6 x 9 Sonys. With an amp like this driving them the only purpose for a sub is to broadcast bass and go deaf. Sound quality is amazing even at lower volumes. Plenty of headroom for my speakers runing this at 50% and under with zero gain.

Pros: Sound Quality. Pumps Bass. Max Headroom. Can Run Without Big Three.

Cons: Big. Heavy. Hard to Mount in Newer Cars with Few Flat Surfaces.

Solid functional amp

Written by: Les from Hilo, HI on April 5, 2016

Crutchfield Customer Review (What's this?)

I mounted the amp under the front passenger seat which fit perfectly and easy to get to the controls! I'm still tweaking the amp but as an amateur I configured it to a good sounding for my car. I'm running the Polk 5 1/4 speakers for the front and it sounds way better than the Sony speakers I previously were running! Maybe I'll get Polk rear speakers for a better bass! I don't have that solid bass but I don't want the loudness of a sub-woofer!

Pros: Easy to hook up and adjust the gain to the speakers!

Cons: If anything, I'm not getting to solid bass from this unit! Maybe it's my rear speakers but not much cons to this unit!

Rockford Fosgate Prime R300X4

Written by: barry from Tampa, FL on March 30, 2016

Crutchfield Customer Review (What's this?)

Very clean 4 channel sound.

Pros: seems to be very efficient.

Cons: None

FOSGATE AMPLIFIER

Written by: r chapa from san antonio, TX on January 30, 2016

Crutchfield Customer Review (What's this?)

WITH THE HELP OF YOUR TEAM, I GOT EXACTLY WHAT I WANTED///BETTER SOUND, CLEARER MUSIC AND WITH A LITTLE UMPFFF. IM VERY HAPPY

Pros: BETTER AND STRONGER SOUND THAN MY ORIGINAL RADIO

Cons: NONE

Terrific amp

Written by: Jontyrees from austin, TX on January 29, 2016

Just installed this to replace an alpine MRPF300 tht never impressed me. Night and day difference. This RF is sooo much better, finally the system sounds like I thought it should. I blamed head units, speakers, previously, but the problem was the two alpine amps, mrp500 and MRPF300. I replaced both with similar rated and priced RF Prime units, and the difference is staggering. Simply switched out the amps, changed nothing else. I'll never use another brand of amp than RF from now on. Oh, and the birth certificate showed 416w RMS, vs 300w rating.

Pros: Great sound, great price, good looking, adjustments on top

Cons: I didn't buy it soon enough

Great amp

Written by: Barto from New Jersey on January 17, 2016

Crutchfield Customer Review (What's this?)

Great amp, very flexible with different setups, using it to drive 6x8 Polk coaxials front and rear and has more than enough power. Very happy with this amp, Install was very easy nice size gives you lots of choices.

Pros: Great power,very clean,very flexible with different setups

Cons: None

Works great

Written by: Dennis D. from Sarasota, Florida on January 11, 2016

Crutchfield Customer Review (What's this?)

Works great. Easy setup.

Pros:

Cons:

Rockford Fosgate Prime R300X4

Written by: 808xN8 from Hawaii on January 4, 2016

Crutchfield Customer Review (What's this?)

Excellent amp. Provides more than enough power for 6 1/2 inch front and rear component speakers that I have in the doors. Also allows me flexibility to change/ upgrade the speakers in the future if wanted. I Have the gain set at half power right now.

Pros: Small and powerful. Looks good and simple to hook up. Sound comes out clear at high volume.

Cons: Not many I can think of yet. To be picky , it could have bigger connections for wire inputs and outputs. They seem small for the power of the amp.

best amp to get for your car speakers clear sound amazing!

Written by: eddie from whittier ca on August 9, 2014

best amp to get for your car speakers clear sound amazing!

Pros:

Cons:

Details

Hands-on research

What's in the box?

Download the Rockford Fosgate Prime R300X4 manual

  • 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

Product Research

Features
Controls
Connections

Features

Overview: The front and rear sections of the Rockford Fosgate Prime R300X4 4-channel amplifier are bridgeable, so it can be wired in 4-channel, 3-channel, or 2-channel mode.

CEA 2006 Compliant: The R300X4'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: 50 watts RMS x 4 at 4 ohms, 14.4 volts, and less than 1% THD+N
  • 2 Ohms: 75 watts RMS x 4 at 2 ohms, 14.4 volts, and less than 1% THD+N
  • Bridged: 150 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.

Controls

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

Connections

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 inputs. 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.

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.

Accessories
Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Purchased this due to its reputation in the industry will not use anything else. [ Rodney  Jun 20, 2016 ]
Brand reputation and customer and Crutchfield ratings. [ harold  Jun 01, 2016 ]
The sales associate help choose this item, which after the explanation was given, it made since to choose this item. [ Lanell  May 06, 2016 ]
Brand [ Walter  Apr 23, 2016 ]
Rockford Fosgate is best brand for amps [ Alex  Mar 27, 2016 ]
are you kidding its RF [ barry  Mar 19, 2016 ]

4 questions already asked

Should be no problem using factory wires [ DENNIS  Mar 17, 2016 ]
THis is personal preference, you can use factory wiring, you'll just need to map out the color codes on wires to get your front and back left to right correct. Typically factory wiring is small gauge wiring, a lot of people prefer large diameter wires, believe to increase sound quality. I prefer larger than factory wires. But it's a lot of work and extra money. Most cases factory should be fine tho. I first noticed difference in sound quality in home stereo, using monster cable instead of small gauge. My ears seem to like bigger cables. Hope this helps [ Richard  Mar 16, 2016 ]
How much watts you need depends on the speakers you plan on using. This amp is 75x4 rms. I'm no expert but usually the peak output is about double the rms. I have the gain set at about 1/2 for front and rear components that rate 50watts rms. it's way more than enough, but allows for future upgrades [ Nathan  Dec 28, 2015 ]
I don't think so. [ JESSE  Sep 24, 2014 ]
We have not received any answers from other customers on your question. I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They should be able to help answer your question. [ Krissy  Sep 16, 2014 ]  Staff
I forwarded your question to an Advisor and they responded with the following: The amplifier has speaker level inputs, so you do not "need" an LOC. It can still help if you want to get the cleanest signal to your amplifier from the factory radio. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Aug 06, 2014 ]  Staff
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