crossovers?

Ok here's the scoop....... Exactly what you told me lol. New amp with rcas ran to it (not factory bmw hook up) and new speakers of my choice. The only thing that can stay (excluding hu) is the factory speaker wire. I would. Give names but I'm doing this from a phone and its nearly impossible to copy and past links. So I will just give the credit to www.e46fanatics.com (if your a BMW owner check it out. THANKS Viking and all you other guys for the help. Probably be needing more help soon so see you next time.