---
product_id: 1155261
title: "Rockford Fosgate R400-4D Prime 400 Watt Full Range Class-D 4-Channel Amplifier"
brand: "rockford fosgate"
price: "€ 670.71"
currency: EUR
in_stock: false
reviews_count: 9
url: https://www.desertcart.sk/products/1155261-rockford-fosgate-r400-4d-prime-400-watt-full-range-class
store_origin: SK
region: Slovakia
---

# Rockford Fosgate R400-4D Prime 400 Watt Full Range Class-D 4-Channel Amplifier

**Brand:** rockford fosgate
**Price:** € 670.71
**Availability:** ❌ Out of Stock

## Quick Answers

- **What is this?** Rockford Fosgate R400-4D Prime 400 Watt Full Range Class-D 4-Channel Amplifier by rockford fosgate
- **How much does it cost?** € 670.71 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.sk](https://www.desertcart.sk/products/1155261-rockford-fosgate-r400-4d-prime-400-watt-full-range-class)

## Best For

- rockford fosgate enthusiasts

## Why This Product

- Trusted rockford fosgate brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Description

Since day one, we have spearheaded the car audio revolution. Nothing has changed. Rockford Fosgate is still the global leader in audio innovation and your passion is our purpose. We engineer the best audio systems for your lifestyle!

Review: A great product that serves me very well! - I installed a modest sound system in my '04 Silverado Ext. cab. I wanted a system that would provide quality sound and at a satisfying volume. I wanted crisp highs and deep lows with a punch. I did my 'homework', learning about sound quality, and what to look for in quality sound products, read reviews (thank you for your reviews!), and shopped with desertcart. I replaced the factory cd/stereo with a quality double din receiver. I gladly bypassed the factory wiring harness (saving myself $80.00 and a lot of problems). I did use the speaker wires and radio ground wire from the harness and ran new power and remote wires. 8ft rca cables from the receiver to the amp. The amps front channel powers a set of infinity kappa 6.5" door speakers rated at 220watts peak. The rear channel is bridged and powers a quality 10" flat subwoofer rated at 800watts peak. The sound is amazing! If you take the time to learn what the amp settings are and how they are to be used. I have learned that 'more' isn't always better. Low gain, for instance, is preferable to high. My front gain is set to about half-max. Freq. set to just passed half. If I had to guess, I'd say around a hundred hertz. The infinity's get pretty low w/o distortion. I have the amp in 4 channel mode because of the sub, otherwise. The rear channel, bridged into 4 ohms puts out about 200 watts according to specs. The gain is only turned up a third, if that much, which is amazing because it's kicking my ass. I had it higher at first but it was overpowering. The frequency is set just below a hundred hertz or just about where the front channel leaves off. It's a beautiful blend. The punch-eq is set to close to half and provides plenty punch for me. It's all working great together. I feel that I have more than enough volume. I have no distortion at tolerable volumes. The amp gets warm but not hot. I used 10 gauge power and ground wires. The ground is clean and solid. Mounted the amp on 'the hump' under the backseat next to sub. Plenty of clearance in this location. Well, I couldn't be happier with my purchase. I hope my review will be of help to you. One more thing that I should mention. Each amp is rated I guess before shipment and my 400 watt amp actually rated at 525 watts. I believe I benefit from the extra wattage. *** A couple of weeks later... I love the sound of my system! This amp was a Great buy for me!
Review: so roughly 20 years ago I used to work in a high end car stereo shop and we used Rockford amps pretty much all the time - Ok..so roughly 20 years ago I used to work in a high end car stereo shop and we used Rockford amps pretty much all the time. Back in that day...Rockford amps "were the $hit" so to say. Plenty of power and well made but expensive. (at least to a 19 year old) When I decided to do a simple system (new head unit, front and rears and single 8 inch sub) in my truck I wanted amps that were small and easy to hide. When I found these amps the size looked good and price was amazing and they had the Rockford Fosgate name that I remember so fondly so I gave it a try. Once I had it all hooked up and tuned everything I was blown away. I cant believe technology has come so far as to offer Class D amplification at such a great price. I have it running off a Pioneer head unit to a pair of 6.5 Infinity component speakers in the front doors and channel 3/4 are bridged running a single 8 inch Infinity sub in a sealed box. The amp was small enough to mount under the passenger seat and no one even knows its there. My sub is also in the factory location which other than the head unit, makes my system pretty stealthy, until you hear it. Some of my friends thought I had at least a pair of 10's and were expecting to find a much bigger amp in the back of the truck. Im very happy with the sound and power of this little amp. I may decide to upgrade everything and get the monoblock version of this for the sub and use all 4 channels in this for the full ranges in the doors. They also make "marine" versions of these amp which I will use for sure in my boat if I ever decide to build that system as well.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B004T0WFVE |
| Brand | Rockford Fosgate |
| Customer Reviews | 4.3 4.3 out of 5 stars (595) |
| Date First Available | March 21, 2011 |
| Global Trade Identification Number | 00780687333119 |
| Height (inches) | 5 centimeters |
| Is Discontinued By Manufacturer | No |
| Item Weight | 5 pounds |
| Item dimensions L x W x H | 9.1 x 6.8 x 2 inches |
| Item model number | R400-4D |
| Manufacturer | Rockford Fosgate |
| Maximum Supply Voltage | 12 Volts |
| Minimum Supply Voltage | 9 Volts (DC) |
| Mounting Type | Car Mount |
| Number of Channels | 4 |
| Output Power | 400 Watts |
| Package Type Name | Retail Packaging |
| Product Dimensions | 9.1 x 6.8 x 2 inches |
| Specification Met | Industry Standards |
| UPC | 780687333119 613815588740 |
| Voltage | 12 |
| Weight | 2.1 Grams |
| Width (inches) | 17.2 centimeters |
| Wireless Remote | No |

## Product Details

- **Item dimensions L x W x H:** 9.1 x 6.8 x 2 inches
- **Manufacturer:** Rockford Fosgate
- **Maximum Supply Voltage:** 12 Volts
- **Minimum Supply Voltage:** 9 Volts (DC)
- **Voltage:** 12

## Images

![Rockford Fosgate R400-4D Prime 400 Watt Full Range Class-D 4-Channel Amplifier - Image 1](https://m.media-amazon.com/images/I/210f8ZtRXeL.jpg)
![Rockford Fosgate R400-4D Prime 400 Watt Full Range Class-D 4-Channel Amplifier - Image 2](https://m.media-amazon.com/images/I/61YIAE28uBL.jpg)
![Rockford Fosgate R400-4D Prime 400 Watt Full Range Class-D 4-Channel Amplifier - Image 3](https://m.media-amazon.com/images/I/81E-vIUs3VL.jpg)
![Rockford Fosgate R400-4D Prime 400 Watt Full Range Class-D 4-Channel Amplifier - Image 4](https://m.media-amazon.com/images/I/81SYvgnu9sL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ A great product that serves me very well!
*by C***N on July 22, 2013*

I installed a modest sound system in my '04 Silverado Ext. cab. I wanted a system that would provide quality sound and at a satisfying volume. I wanted crisp highs and deep lows with a punch. I did my 'homework', learning about sound quality, and what to look for in quality sound products, read reviews (thank you for your reviews!), and shopped with Amazon. I replaced the factory cd/stereo with a quality double din receiver. I gladly bypassed the factory wiring harness (saving myself $80.00 and a lot of problems). I did use the speaker wires and radio ground wire from the harness and ran new power and remote wires. 8ft rca cables from the receiver to the amp. The amps front channel powers a set of infinity kappa 6.5" door speakers rated at 220watts peak. The rear channel is bridged and powers a quality 10" flat subwoofer rated at 800watts peak. The sound is amazing! If you take the time to learn what the amp settings are and how they are to be used. I have learned that 'more' isn't always better. Low gain, for instance, is preferable to high. My front gain is set to about half-max. Freq. set to just passed half. If I had to guess, I'd say around a hundred hertz. The infinity's get pretty low w/o distortion. I have the amp in 4 channel mode because of the sub, otherwise. The rear channel, bridged into 4 ohms puts out about 200 watts according to specs. The gain is only turned up a third, if that much, which is amazing because it's kicking my ass. I had it higher at first but it was overpowering. The frequency is set just below a hundred hertz or just about where the front channel leaves off. It's a beautiful blend. The punch-eq is set to close to half and provides plenty punch for me. It's all working great together. I feel that I have more than enough volume. I have no distortion at tolerable volumes. The amp gets warm but not hot. I used 10 gauge power and ground wires. The ground is clean and solid. Mounted the amp on 'the hump' under the backseat next to sub. Plenty of clearance in this location. Well, I couldn't be happier with my purchase. I hope my review will be of help to you. One more thing that I should mention. Each amp is rated I guess before shipment and my 400 watt amp actually rated at 525 watts. I believe I benefit from the extra wattage. *** A couple of weeks later... I love the sound of my system! This amp was a Great buy for me!

### ⭐⭐⭐⭐⭐ so roughly 20 years ago I used to work in a high end car stereo shop and we used Rockford amps pretty much all the time
*by A***R on August 9, 2014*

Ok..so roughly 20 years ago I used to work in a high end car stereo shop and we used Rockford amps pretty much all the time. Back in that day...Rockford amps "were the $hit" so to say. Plenty of power and well made but expensive. (at least to a 19 year old) When I decided to do a simple system (new head unit, front and rears and single 8 inch sub) in my truck I wanted amps that were small and easy to hide. When I found these amps the size looked good and price was amazing and they had the Rockford Fosgate name that I remember so fondly so I gave it a try. Once I had it all hooked up and tuned everything I was blown away. I cant believe technology has come so far as to offer Class D amplification at such a great price. I have it running off a Pioneer head unit to a pair of 6.5 Infinity component speakers in the front doors and channel 3/4 are bridged running a single 8 inch Infinity sub in a sealed box. The amp was small enough to mount under the passenger seat and no one even knows its there. My sub is also in the factory location which other than the head unit, makes my system pretty stealthy, until you hear it. Some of my friends thought I had at least a pair of 10's and were expecting to find a much bigger amp in the back of the truck. Im very happy with the sound and power of this little amp. I may decide to upgrade everything and get the monoblock version of this for the sub and use all 4 channels in this for the full ranges in the doors. They also make "marine" versions of these amp which I will use for sure in my boat if I ever decide to build that system as well.

### ⭐⭐⭐⭐⭐ Loyal to Rockford Fosgate
*by A***D on August 29, 2017*

Amplifier arrived and the birth sheet stated 561watts. 561watts from a 400watt amp, I mean damn thats whats up. I always count on Fosgate for excellent products. I will always buy Fosgate products for my car audio needs. This is my second amplifier from RF, I currently have a 1200watt for my dual 10" P2D2's and they slap so hard. I decided to buy an amp for my door speakers. When the amp arrived the gain knobs looked a little tweaked and the amplifier turned out to be defective. Amazon immediately sent out a replacement. Amazon is the best place to buy anything in my opinion, excellent customer service and good prices. Update: Replacement arrived and installed. All wiring checked. Amp is working correctly at this time. Birth sheet stated even higher power then my original amp. Eventhough I received a defective RF product originally, I will continue to only purchase RF amps as I believe they make very high quality products.

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*Product available on Desertcart Slovakia*
*Store origin: SK*
*Last updated: 2026-02-22*