Having absolutely no experience in car audio installations, I am confused with some of the terminology which is greatly affecting my choices in component speakers, namely speaker mounting depth. What are the differences in "top mount", "surface mount", "bottom mount"? (Take it easy!!) Do any of these options result in cutting out the door panel speaker grille? If so, does that give extra depth? I don't mind this option if I can get more depth, or more importantly, the speakers that I really want to fit in to relatively limited speaker depth area. Thanks in advance!