I do have the MBQuartz. Just wondering how many speakers came with the car, I can count 4. Just wondering if I can add any or change them to get more bass. Thanks

 

Most S2000s have a single set of component speakers -aka four total. Are you using the stock deck? What year is your S?

 

To elaborate, you have 2 6.5" speakers in the door and two tweeters. The best upgrade would be a set of components with an in-line crossover. This would be more noticeable with a proper amp, of course! The AP2's came with slightly better stock speakers, but a good head unit and upgraded components goes a long way.