Short ground wire. Not to battery. Tight ground point=no noise.

 

Ok , for those installing the Rockford Fosgate PBR300X2 amp.... I had a long talk with the tech dept at RF today about the setup of the amp, as some had asked and I needed to know as well.. FIRST thing...." on a motorcycle system GROUNDING TO THE BATTERY IS PERFECTLY FINE AND RECCOMENDED" .." if you have a less than stellar grounding terminal due to the fact that the frames are usually powdercoated .. AS PER YAFFE'S INSTRUCTIONS".... Next , and I quote again "the instructions that come with the amp are basically designed for cars", as the frame/body of cars usually has excellant grounding points and the amp is usually too far from the battery .. ground wire needs to be 4' or shorter and #10AWG.. as per RF's tech man....

now as far as tuning the system...turn gain down fully (counterclockwise ) ... then start with the amp frequency selector set on HIGH PASS ... then adjust the frequency control **** clockwise fully to block out all bass (lows)... and only pass high frequency....turn up radio to about 70-80% volume .. now start turning the frequency dial down to start allowing more bass --you want full clear sound with no distortion.. stop when you hear it starting to distort and back up a touch...range is 50-500

now with radio up to about 70%-80% volume and no discernable distortion, start adding gain , just as you did the last step.. stop when you get distortion...(I actually had to back my head unit down to about 50% to do this as it was killing my ears at that volume )
More head unit and less gain is better , ...... now this is all word for word as I wrote it down as I was talking to the tech guy...
so I came home and did exactly as he said , and ended up with these settings on my amp for my Polk MM651 speakers .....

frequency selector on ...High pass
frequency dial on..... 110
gain set on .....5

and this thing rocks !!! at exactly 1/2 volume of the head unit , I though the window glass was coming out of my garage !! and crystal clear ... hope this helps ....

 

Thanks for taking the time to post this- I'm going to pull the outer fairing and go through setup again. I didn't consider the head unit itself would be distorting when I had the output at 100%. I have to wear earplugs when I am setting it up- damn this thing is loud.

Why did you set the crossover so high? I think you could probably run it lower and catch some more bass- its hard to tell with fairing off when setting up but with the polk crossovers they should keep the speakers from getting damaged due to too low a frequency.... I think....

 

Man, I can't wait until I get mine in!!! Wish UPS would have delivered my Hawg Wired install kit today!

 

NCJohn, i set the frequency as much bass as I could before the speakers started to vibrate , I had the bass control on the head unit about 3/4 when I did my setup though so that will also make a difference... just gotta play with it , like the tech told me ... everyone has a different ear ... but mine are bleeding right now !!! man this thing is freakin loud!!!!!!..

 

HP=hi pass LP=low pass AP= all pass, Im going to try AP, I want all my music loud.

 

all pass will be loud and....distorted.and .... blow speakers.

 

Excellent. I was wondering why the sound did not impress me. I will battle with the faring tomorrow and start tuning it. A big thank you.

 

Any idea on what to set the Variable High Level Adjustment I'm using high level inputs

 

High Pass is mis leading. People assume Hi pass is a setting you would use for tweeters but Hi pass in that amp is only blocking out anythang under 80hz. I ran on All Pass for few wks. Switch'd to Hi Pass last week. Much Much cleaner sound. All Pass lets way too low frequencies thru. A 5 1/4 or 6 1/2s like I have are not meant to run that low off a frequency.