Rockford Fosgate R300X4 Review – Affordable 4-Channel Option

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The Rockford Fosgate R300X4 is a great 4-channel amplifier if you’re looking for a low-price option to power your speakers and get good performance.

Is a fairly affordable car amplifier that promises adequate power for your speakers to produce nice sound quality and several adjustments to tweak your tunes. It might not be the most powerful amplifier out there, but it’s sure to get your car audio system up and running.


  • Can power both your speakers and subwoofers
  • Nice boost control with the Punch EQ
  • Good cooling through the heatsink chassis


  • Bridged mode incompatible with an impedance lower than 4 ohms
  • Only passive cooling is available


The Rockford Fosgate Prime R300X4 is one of the best car amplifiers give it’s price. Capable of fully powering your front and back speakers or driving your subwoofer through the bridged mode to give you an adequate bass experience.

With its four channels, this amplifier can be used in different settings. It can operate at 4 ohms while providing 50 Watts RMS or it could give you 75 Watts RMS per channel at 2 ohms. This setup offers enough power for your speakers to produce strong sound quality.

However, you’ll probably like using it to drive your subwoofer in the bridged mode. By bridging two channels, the amplifier can run a sub with 150 Watts RMS at 4 ohms.

You can choose to run either two subs together using two bridged channels or work with three channels, one of whom is bridged, to drive one sub and two speakers.

High Sound Quality Control

The Prime R300X4 can work with almost any system. You can connect it to any stereo using the high-level input and get great sound quality.

The output performance won’t disappoint you as it has built-in Butterworth crossover filters with 12 dB/octave. Both high and low filters support variable frequencies.

You can also control the bass boost level using the Punch EQ Control and adjust separate gains for your front and rear channels to tune the performance to your liking.

Construction and Protection

The amplifier has a cool-looking chassis designed to protect against high temperatures and uses a cast aluminum heatsink to draw and dissipate the heat.

The built-in sensors constantly monitor the outputs to ensure no overload, thermal or short circuit damage could happen.

Features & Specifications

  • Amp Class: AB
  • Bridgeable Output
  • 50 Watts x 4 channels at 4 ohms
  • 75 Watts x 4 channels at 2 ohms
  • Bridged Mode: 150 Watts x 2 channels at 4 ohms
  • Total Power Output: 300 Watts
  • Selectable Bass Boost: 0, 6, 13 dB at 45 Hz
  • Frequency Response: 20 – 20k Hz
  • Variable Filters: 50 – 250 Hz, 12 dB/octave Butterworth Crossover
  • Separate Gain Control for Front and Rear Channels
  • Signal to Noise Ratio: >100 dB
  • MOSFET Power Supply
  • 4 Gauge Power/Ground connectors
  • Dimensions: 13.19’’ Width x 6.77’’ Depth x 1.98’’ Height

Last update on 2024-06-13 / Affiliate links / *Image Disclaimer: We use images/data from Amazon Product Advertising API solely on products that link to Amazon. On products with the "Price at Crutchfield" button, we use images/data from as per the partnership deal.

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