I assume there must be a crossover somewhere in the Fit Sport which ensures that the factory tweeters are fed with the correct frequencies. Does anybody know where this crossover's located? I know very little about ICE so please accept my apologies if I've asked my question in a technically incompetent manner. In fact, is there an external crossover or does the head unit have a dedicated output to the tweeters?

 

The tweeters are protected with a simple capacitor. They are fed from the same signal as the door speakers. Its very simple, fairly reliable and rugged. Once you upgrade to an aftermarket set of components you will get a set of crossovers with the mid/tweeter combo.