what are you looking to spend? are you using either or on the bass setup? i run both amps in my current setup, but coming from a DC1100.1, i was going to stick with a 6.0 on the bass, but my dealer informed me that the 6.0 isnt great on the bass end of things because of heat issues. i would definitely go with a 9.0. i am super thrilled with that amplifier on the bass and the 6.0 on the fronts.