I started my Axiom journey with M2's and a small Yamaha sub and they sounded really good together. IMHO adding a sub will really step things up for you, and I find it add realism to the music experience. Depending on the size of your room and listening levels an 8in and at most a 10 inch sub should do the trick. For music you don't want to over do it, just enhance .
DOG is GOD spelled backwards. What others think of me is none of my business. M80 V3 MY GLOSS Cherry