Ok im on like my 4th box for the Treos b/c im unable to build a portd box for em that will fit in my trunk and still sound good. Right now i have 2 sealed at abotu 2cu.ft. each and it sounds better than any ported ive had so far. My question is that if i get rid of my 2 15" SSIs would 1 SSX pound harder? given the fact that i woudl have room for a proper enclosure and all? I have a Diamond audio 1750rms amp to power it. My thinkin is that one SSX in a good ported box will be louder than the two SSIs sealed, but i could be wrong...I may upgrade the amp also.