The ground does not have to be run back to the battery, any bare metal spot on the frame or triple tree should do. I have mine grounded to the unused threaded hole in the triple tree with no issues. You could try the spot that UltraNutZ mentions on the side of frame near neck if you want to by-pass the triple tree. I have my RF set to HP with freq between 60-70hz and gain @ 5 with no problems and I push it fairly hard.

 

10 guage kit that I purchased from Car Toys with a 30 amp fuse. Ground running to triple trees. I believe my amp is set at AP with gain around 11 o'clock position. Used the "by ear" method in UltraNutz instructions.

Check out UN's step by step installation for this setup in the stickys. I followed it to the letter, and have had no issues at all. I run this thing blasting all day long. Of course, only have about 3000 miles on the setup so far, so can't speak to longevity, but really am not having any of the issues that others have been reporting.

 

in your first post you stated that you're running 4 ohm speakers. In this post you state that you're running MM651 which are 2.7 ohm speakers. Can you clarify for me please

 

They are Polk Audio MM651UM which are listed as 4 ohm

 

RF techs usually won't recommend something like this if they think it won't help. The running of the ground back to the battery is not a big deal as long as you don't wind up with engine noise.

You mention that you think the ground is suspect. What size ground wire are you using and where exactly is it grounded.

 

Are you sure you have the Polk MM651UM's? The grills on those are not removable so you can't mount them in the fairing and they are 4 ohm speakers. The Polk MM651's are 2.7 ohms even though I believe they say 4 ohms on the box. The MM651's are what you should have if you have them mounted in the fairing. The link below shows what you should have...

http://www.sonicelectronix.com/item_...dio-MM651.html

 

I listed the correct part number...I 'removed' the grills to make them fit properly.

 

I cant remember what guage the ground wire is...I used what came with the 10 ga install kit that I purchased.

 

RF and Yaffe both recommend running the ground to the battery..

 

I had this problem with the 4 channel amp. The issue is the amps over heat as you crank the volume on the radio. You need to get a high/low bypass filter and install in on the speaker wires coming out of the radio. Very simple. One end connects to the 4 speaker wires which then connect to the fosgate harnes which you plug into the amp. There is a dial on the bypass for left & right. Set the amp gain at 5 and then put the volume on the radio to the "M" on volume. That should be a good starting point to adjust every thing.

I have an FLHTC and after connecting the bypass all my volume, clipping issues were over. I have Hertz 6.5 speakers and the sound is awesome...

Just make sure you connect the ends correctly not backwards.

Also I leave the high pass filter on the amp to normal giving me nice low end, just keep the bass and the treble low on the radio, maybe 2 or 3 bars tops.

Bykerbill