Ok. I have a couple of questions. Right now i have an alpine ida-303 deck in my 350z along with 2 10 inch he2s 400rms on a sony xm-1s amp in a sealed box.... my friend just gave me his 12 inch fosgate p3 500rms. i dont have a box for it but what would be louder? and if i do get a box for the p3 it would be a ported box... thanks