So I want to upgrade my 2004 Honda Civic SI stock sound system. The stock system has two front and two rear speakers. Let's say I replace these speakers with 3, or even 4-way speakers combined with a two channel 200W amp and also a subwoofer (not sure about size). Would it be necessary to add tweeters? I realize sound quality may totally vary on the quality of the speakers, amps, etc... But I would be happy to hear any advice, ideas, or criticism to what I've suggested. I'm fairly new to car audio.