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

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!

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.

Installed in my 88 YJ running my mids and highs 2x1" 4 x3.5 3ways gives my system the boost it needs, RF has never failed for me. This is paired with an RF 500 mono running a pair of R2D2 10"@2ohms and the total system hits and sounds great. with this on mid/highs the bass can hit hard and doesn't distort the sound, so you can actually feel the beat hit and understand the music as well!

This Amp sounds Awesome!It powers my 4 Infinity Kappa 682.11's perfectly. It is paired with an Alpine 500 watt mono amp that powers 2 - JL 10w1v3's in a dual enclosure under my back seat. This combination sound chrystal clear, extremely loud and killer bass. I'm extremely happy. I bought this amp to replace an Alpine amp of similar specs (but was 2x the price) that i burned up when i left my sun roof open when it rained and the water apearantly leaked down through my seats and into the amps power supply. I had just wiped down the seats and center console, etc with a towel and drove away. About a mile down the road my door speakers stopped working and I knew immediately that I just made a dumb move. Anyway, I was weary of the Prime series in the beginning when I was building my system, but now I'm a believer... Buy this amp! You can't beat the quality for the price! And if you ever get rain in your car be very careful because you never know where the water can end up!