chenishead

Mine are rattling and I want to fix it. Offhand, I do not know much about audio, but is it possible to replace the speakers and keep the stock head unit? I

diagnosticator1

You must remove the door panels. Yes, replacement speakers are a sure improvment.

chenishead

speakers? Or can I just buy whatever fits and hook it up?

diagnosticator1

There is a lot to consider regarding replacement speakers, the size must be compatable, and the impedance must be correct, IE, 4 or 2 ohms. Besides, these requirements, the depth must not be too great, or window interference will occur. One excellent speaker upgrade is Infinity Kappas.
I recommend you consult an installer. I installed upgraded speakers in my A4, but to do so, I had to use the OE speaker chassis, modified to mount the replacements on. The new speakers have coaxial tweeters, and the cross over is mounted inside the OE speaker chassis. Finally, the tweeter channel wires must be disconnected from the OE tweeter speaker and connected to the new speaker cross over inside the modified OE speaker chassis.

MacSub

Make sure you get proper 2 way components with their own crossover.

diagnosticator1

I see your contentious contributions to my replies continues...but your comments are important info for the OP regardless. :&gt