I have a 1.6 mazda 3 2010 non bose system, I would like to add an amp with kenwood, JBL, pinoner. All i know is that i will need a (LOC) so now im asking if i add the amp where should i put it as it will be big, and will it boast my speakers or will it have little effect? I am also thinking about putting a sub later on and tweeters, but my main question is pretty much will the amp make a difference or will i also need new speakers