Stock Speaker Question
 

Does anyone know how the front (tweeters and door panel) stock base (non-Infinity) speakers are wired?
Specifically, are they using the same channel to power both and crossed over? Are they bi-amped via the stock radio? Or does full bandwidth go to door speakers and tweeters just have simple hi pass filters? etc.
I'm asking cause I'm looking into putting in an aftermarket radio but using the stock speakers for now. I need to know if I need crossovers and how to wire the radio exactly, etc.