# Rockford Fosgate PBR300x1 "Boosted Rail" Mini Amp Review



## bigdwiz (Oct 7, 2010)

I picked up the PBR300x1 just a few days ago and couldn't wait to get it on my test bench and see how it performs.

The birthsheet stated over 300 watts at 1ohm RMS and over 900 watts peak! This amp is TINY....almost small enough to fit in my pocket. See an overview of the amp in addition to testing bass output from an array of subwoofers ranging from 8-12"

I had plans on making one video for the unboxing, overview, subwoofer test and RMS wattage output test, but it was going to end up too long. I decided to break down the review into 2 parts. The first video includes the unboxing, overview and subwoofer test. I'll update this thread with the RMS wattage output I measure using my setup. I also have plans to test this amp out in my car to get an idea of how it works in a daily driver and will update and let everyone know how it performs in a modest setup.

Questions, comments and constructive criticism welcome...


See video on YouTube in 1080p HD

or embedded below:







**NEW* - See Part 2 of the Demo:*

See video on YouTube in 1080p HD

or embedded below:









Also, some beauty pics:


----------



## trumpet (Nov 14, 2010)

Thanks, D. Do you have the 2nd part of the review in the works?


----------



## bigdwiz (Oct 7, 2010)

trumpet said:


> Thanks, D. Do you have the 2nd part of the review in the works?


Yes, it is currently rendering in Sony Vegas. I should have it online tonight... :rockon:


----------



## bigdwiz (Oct 7, 2010)

I've been questioned and should emphasize, I purchased this amp...It was NOT sent to me by Rockford or anyone else to review and send back. I purchased the amp from Car Toys through Amazon and my review is completely unbiased (well, other than my liking for the old school Rockford amps). I just wanted to make this clear so people didn't think I was doing a "favor" for someone by reviewing this amp....


----------



## sirvent_95 (Feb 14, 2011)

bigdwiz said:


> I've been questioned and should emphasize, I purchased this amp...It was NOT sent to me by Rockford or anyone else to review and send back. I purchased the amp from Car Toys through Amazon and my review is completely unbiased (well, other than my liking for the old school Rockford amps). I just wanted to make this clear so people didn't think I was doing a "favor" for someone by reviewing this amp....


How do we REALLY know they didn't send this to you for review, HUH?

I would like to see documented evidence of all mail and packages 
you receive at your home and workplace. Just to be sure I'll also need 
to see the same documentation for all living relatives. 
Maybe then we'll really know you are just sharing your experience 
to help your peers make an educated buying decision.

Of course, I just posted this reply for fun. I appreciate it when I can
hear firsthand about a new product. Thanks a lot for taking a plunge 
with this new technology.


----------



## bigdwiz (Oct 7, 2010)

sirvent_95 said:


> How do we REALLY know they didn't send this to you for review, HUH?
> 
> I would like to see documented evidence of all mail and packages
> you receive at your home and workplace. Just to be sure I'll also need
> ...


LOL! :laugh:

The main reason I stated this fact above is these days when you see a product review, it's usually from who? The manufacturer or a dealer? Are they going to say anything bad about the item? Doubtful. I think in order to retain ethics, I'll continue to buy my products for review and if I'm EVER sent one by a company or manufacturer, I will let it be known up front and won't hold back on the negatives....

Sorry to be so serious about this but I do take it seriously....and I spend mucho $$ on stuff to review and talk about, but it is my hobby and I enjoy making the vids.

Thanks as always for watching and commenting :thumbsup:

BTW, my aging computer crashed rendering the 1080p video of Part 2, so I'll do my best to have it online tonight. Time to stop buying audio gear and buy a new computer!


----------



## Coppertone (Oct 4, 2011)

Excellent review of this amp, thank you for sharing it with us. In your opinion could this be used to power my Alpine SWR-823D subwoofer effectively? I'm doing the sound system in my 2000 VW Gti, and want to maximize my space.


----------



## pjc (May 3, 2009)

My brother runs this mono and the 4 channel in his wife's Solstice. The mono runs a factory 8" at 2 ohm if I remember correctly. He was able to find a factory enclosure and sub for cheap. He was going to eventually replace it with an aftermarket. But he swears it sounds really good. I think for his application and just lack of space it's perfect. He loves it and swears by it and the 4 channel. If there was a 2 channel or the 4 was bridgeable I would definitely try em out.


----------



## bigdwiz (Oct 7, 2010)

Coppertone said:


> Excellent review of this amp, thank you for sharing it with us. In your opinion could this be used to power my Alpine SWR-823D subwoofer effectively? I'm doing the sound system in my 2000 VW Gti, and want to maximize my space.


Thanks for the comment. This amp should provide your 823D with 250 watts of clean power at 1ohm (13.8v), so if you think that's enough for this sub, then it may just work for you. I want to get either an 823D or Image Dynamics ID8 D2 and see how this amp matches up. I bet two of these amps and two of either of those subs would be impressive!

Let us know if you pick one up how it works with the Alpine 823D.


----------



## kvndoom (Nov 13, 2009)

sirvent_95 said:


> How do we REALLY know they didn't send this to you for review, HUH?
> 
> I would like to see documented evidence of all mail and packages
> you receive at your home and workplace. Just to be sure I'll also need
> ...


Show me the birth certificate! uh, birthsheet!


----------



## bigdwiz (Oct 7, 2010)

pjc said:


> My brother runs this mono and the 4 channel in his wife's Solstice. The mono runs a factory 8" at 2 ohm if I remember correctly. He was able to find a factory enclosure and sub for cheap. He was going to eventually replace it with an aftermarket. But he swears it sounds really good. I think for his application and just lack of space it's perfect. He loves it and swears by it and the 4 channel. If there was a 2 channel or the 4 was bridgeable I would definitely try em out.


Yeah, I was hoping RF would come out with a 5ch version using the two combined. I'm planning on getting the 4 channel one soon as well. Plans are to use both along with a JL Stealthbox in our Sequoia for a completely stealth system. Amazing with the size of the SUV, you'd think there would be room for amps...


----------



## GoLow (Mar 4, 2010)

Good review.Thanks


----------



## Coppertone (Oct 4, 2011)

I have ordered this from Amazon and should be here by Friday. Review to follow based on my opinion. Looking forward to this lol.


----------



## underdog (Jul 5, 2011)

Good to see your still going

Thanks.


----------



## bigdwiz (Oct 7, 2010)

I just updated the original post with the 2nd Part of my review, showing the RMS power output test...


----------



## GoLow (Mar 4, 2010)

bigdwiz said:


> I just updated the original post with the 2nd Part of my review, showing the RMS power output test...


Excellent.What toy are you testing it with in the vid?


----------



## bigdwiz (Oct 7, 2010)

GoLow said:


> Excellent.What toy are you testing it with in the vid?


I'm guessing you are referring to the o'scope? It is a Velleman HPS50. I also have a couple of resistor banks (only one is shown below). I can now support 4 ohm loads (1, 2 or 4 channels), 2 ohms (1 or 2 channels) or 1 ohm (1 channel). I can also support 8 ohm loads, but I only use these for testing home audio gear.


----------



## GoLow (Mar 4, 2010)

bigdwiz said:


> I'm guessing you are referring to the o'scope? It is a Velleman HPS50. I also have a couple of resistor banks (only one is shown below). I can now support 4 ohm loads (1, 2 or 4 channels), 2 ohms (1 or 2 channels) or 1 ohm (1 channel). I can also support 8 ohm loads, but I only use these for testing home audio gear.


Nice little setup there.Now I want one. Thanks


----------



## Jonny Hotnuts (Mar 15, 2011)

...yeah....gonna need to see a gut shot!!!!

If I ask real nice you figure you could pop the bottom off so we could see how much **** RF was able to pack in a 5 pound sack????
They not only have a power supply and outputs big enough to make 300(ish) but also XO in that small box? Kudos to RF no doubt. 

BTW:

REALLY enjoy your reviews and vids. Cool stuff and keep up the good work. 

~JH


----------



## PPI_GUY (Dec 20, 2007)

I knew there was something suspicious about Dereck...he's a Heel fan!!! LOL!
Wondering how RF got to their claim of 315 watts rms @ 1 ohm with less than 1 volt more without clipping? That's about 20% more output. 
And honestly, they should just leave that "944 watts peak" junk out. I've always thought RF should be beyond outlandish claims like that. The only way that little amp is going to make 944 watts is if a Delorean and a Clock Tower are involved.
Another good job Dereck! 
And *GO CATS!*


----------



## bigdwiz (Oct 7, 2010)

Thanks guys. I wanted to open this little joker up, but didn't want to void my warranty. You can get a pretty good idea of the "guts" by seeing the video Steve Meade took back in January 2011 at CES. The RF engineer gives a great description of the technology and how the amp works. 

And to Mark, no hatin' on my UNC 1982 Championship Can!!

See the vid here:


----------



## trumpet (Nov 14, 2010)

I was trying to find that video last night but I found another good video that explains the Boosted Rail topology.


----------



## bigdwiz (Oct 7, 2010)

^^ Great vid, not sure how I missed it. It looked like an ad on YouTube so this may be why...


----------



## niceguy (Mar 12, 2006)

Guys I hope it's cool to bump this instead of making a new thread about the same thing (if not, please move it):

I'm going to be needing an amp for my front door speakers (ID CTX65 coax for now, old DIY comps later) soon and all I have now is an old Next Vrz4.400 that's really too bulky to fit under my '08 Uplander seat. Yesterday my little brother tells me about these RF amps that are the size of a deck of cards almost so here I am...

I haven't found much info except on motorcycle sites, but has anyone here been running any of these mini amps? I'm mostly concerned about durability and reliability-they seem too good to be true and more like a novelty item and I'm just looking for some feedback on them if possible.

I'm using an old (are you sensing a trend here lol?) Pioneer 860mp so I don't need an active capable amp, and something small like these tiny amps would be so cool....

Thanks!

Jeremy


----------



## Chaos (Oct 27, 2005)

We have been installing them for about a year now, mostly on motorcycles and other recreational vehicles. They have been reliable so far, but I would not recommend them for high fidelity applications.


----------



## rich20730 (Feb 13, 2012)

I've been running my rears and tweeters off of the 300x4 since January and haven't had any problems with it.











Sent from my iPad using Tapatalk HD


----------



## niceguy (Mar 12, 2006)

It's so tempting....I know some don't recommend it for front stage duty but since I'd be using my HU for processing, it's so tempting because of the price.

I'm not in a hurry to add a sub since my work van has such limited space so a 4 channel would be fine for now and later this year I could find a decent 5ch mini (Polk, Alpine, Kenwood,etc)....


----------

