in the dash there are 2 4x6 inch speakers on the custom floor kicker mounts there are 2 6.5inch with tweeters, and behind me are two speakers of withc i dont know what size and under neath my seat is an Alpine 3522 amp, i want to replace these speakers but i have now idea what to get but i also have two brand new subs and amp coming in to put behing the seats so i guess the overall question is what should i get for speakers?