Financial restrictions are disallowing me from doing the stereo install I really want at this time. In place of 3000 dollars of equipment, I just want to replace the stock in-door coaxials with either coaxials, braxials or two way components and just use the stock reciever and amps.

I know that each speaker has its own amp, but I do not know how everything is wired up, or if the stock amps can properly drive aftermarket speakers.

Will I have any problems replacing the stock in door speakers?