Biketronics is the way to go for amps (and speakers) IMO. The amp will make a huge improvement in volume and clarity as you won't be driving the head unit so hard which will distort the sound when you get towards the north end of the volume scale...The 2180 will suffice, if you plan on more speakers down the road, bite the bullet and get the 4180. I have the 4180 running Biketronics 7.1's up front and 6.5's in the saddlebags; Hogtunes tweeters are running off the Sony head unit and my bike has great CLEAR sound well beyond a volume my ears can handle.

 

I have the boom audio setup and my quality of sound is poor unless I use my iPhone using the radio sound is like it is distorted or a lot of treble