I usually read the touring section but I hope I will get a better answer here.

I have a deadcenter fairing and I have installed a Sony DSX 100 head unit, Polk MM651 speakers and ARC 125.2 (very tight fit) amp.

The instructions with the amp on set up are vague and I read the sticky on setting gains but that is way beyond me. I read in another thread that with this amp I am better off turning off the BX because at the high volume on a bike it just distorts sooner.

Can someone give me the amp setting for dummies version.

I am also planning on wrapping the speakers with polyfil, I dont know if it will do anything but its cheap.

I also read something about line levelers, I dont know what they are but should I add one?

 

yes sir here you go.

1. turn your radio's bass, treble, eq settings all to FLAT, not - or + numbers but flat
2. turn your gains on your amp down to 0 (usually all the way to the left)
3. drop in a good CD and turn your radio volume up until you start hearing distortion then back it off a hair
4. now turn your amp gains up until you start hearing distortion and then back if off a little
5. now you're set.

As for the BX, i'm not 100% sure what to tell you there but I've read many a times that's exactly what it does. Whatever you do, make sure to wrap those speakers in your fairing with polyfil.

 

imo it sounds better with the BX in the off position.