I am in the process of selling my current sub/amp/box setup and going more SQ this time. I have decided on the Phoenix RSd 12" sub in a 1.8^3 sealed enclosure. Now time for the amp, originally i was going to get the bigger brother of the m450, the MRP-M650. But recently ive been thinking if i should get something with possible upgrade room, maybe the Hifonics BXi 1206D. That way if i ever got another sub i could run them at 1ohm, or any sub that would do 1ohm. I believe the RSd can take 700-900rms through what ive read. So would the Hifonics be a better decision, its only like ~$30 more.