hey guys what size are the tweeters and speakers (below the tweeters) in the 03 s2000? I wna put my buddies in if they fit. what head unit do u guys recommend? and what else would I need for the quality n loudness 2 go up for example how u can't hear jack on the freeway

 

Start here:

S2000 specific Audio FAQ:
https://www.s2ki.com/forums/index.php?showtopic=295344

 

That's a great FAQ, I know it answered a lot of my questions. I basically had about the same concerns as you, to be able to hear the music loudly while cruising at 75 on the highway with the top and the windows down. Since, I really didn't have much of a reference point, I did it piece by piece. I started out replacing the headunit (they all put out around the same wattage) and added some Alpine Type R 6.5" 100 RMS speakers to the doors, hoping this would solve the problem. Well, I could certainly hear it much better now on the highway, but not loud enough. And when I said loud, I don't mean mind-numbingly loud, just kind of like at a live bar band type loud. So, my next step is to add an Alpine amp and a Sub. This should do the trick, so I hope this helps with your decision. Bear in mind that I have an MY '00, so the headunit/speakers were really crap. I believe the 03's and on were much better. The funny thing is, not only is there a huge difference volume/clarity-wise between top down and top up, but there is also a big if you have the windows up or down when your top is down. With the windows up, it is louder and clearer, with both the windows and the top down, you literally have to turn the volume up a couple of notches to compensate for all the extra wind noise that would other-wise have been blocked out by the top and windows.