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Rockford Fosgate Prime R300X4
4-channel car amplifier 50 watts RMS x 4
Item # 575R300X4 | MFR # R300X4
$169.99 Earn up to 170 Rewards points
Offers & Financing
Our take on the Rockford Fosgate Prime R300X4 by Crutchfield's Buck Pomerantz
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.
Excellent, clean sound, ran all 4 channels on 6and a half inch polk speakers... well worth the money.
Greg, South amboy, NJ
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
- 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
Rockford Fosgate Prime R300X4 Reviews
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Features and Specs
|RMS Power Output (Watts x Channels)||
50 x 4
|Peak Power Output (Watts x Channels)||N/A|
|Power at 2 Ohms (Watts x Channels)||75 x 4|
|Bridged Power (Watts x Channels)||150 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|
|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||0, 6, 12 dB|
|Bass Boost Frequency||45 Hz|
|Speaker Level Inputs||Harness|
|Parts Warranty||1 Year|
|Labor Warranty||1 Year|
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.
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.
- 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 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.
Why did you buy this?
All the power my speakers need [ Donna May 31, 2017 ]
It was recommended by an advisor to power my speakers [ Samuel May 17, 2017 ]
Have used previously and it is a good product. [ MIRIAM Jan 15, 2017 ]
I needed a good 4 channel amp for my car, since I was running a 2 channel amp. And might I add...it took my music to another level...especially when I took the factory speakers out and added aftermarket. [ Cleotis Sep 30, 2016 ]
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 ]
5 questions already asked
I'm going to go ahead and recommend that you try an amp with a lower rms output. This amp pushes way more than what you actually need and you could probably go a lot cheaper as well and get great sound. If you are running 4 of these I would get a four channel amp around the 100-150 rms range. If you are running only 2 I would stick to an amp with an output no more than 100 and I would really try to find one at 60 if you can. I hope this helps at least a little! [ Cody Dec 09, 2016 ]
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 ]
1 answer I am looking to use this in my garage, hooked up to a car stereo. The 12v power will come from an old computer power supply (psu). What I need to know is how many watts power do I need? Why does the 'details' tab of this product not list the peak output? What is the max output? [ David Dec 27, 2015 ]
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