Hey, Ive got a question. Im wanting to get a new Sub, Just to add on to my current ProMedia 5.1 Ultra. And im just wondering, If I get a new sub, will I have to get an Additonal AMP? Or will it come built in like on the ProMedia 5.1 Ultra. Also, I want a Sub That Hits extremly Hard, and hits that ultra low frequency that makes u dizzy. Any sujustions?