I want to do my doors & my back hacth-area.But,so many people have done this different ways.Some use:1.)Rubberized Spray 2.)Dynamat 3.)B-quite 4.)Rammat 5.)Accumat,and 6.)Quite-note.I'am to find-out which is cheaper;but still works well.I Plan to install:two 15"subwoofers,or three...