The e46 standard sound is pathetic to say the least. The speakers are cheap sounding dual paper cone units powered by an average quailty 20x4 amplifier in the head unit, add to this that the front door spekers are mounted directly on the door pad, and not in the door itself, and you sort of get the idea why it sounds so crap.
As an audiophile, I knew what i was getting into when i purchased the car, its just that I never really gave thought to what a headache it would be to upgrade the sound system. The head unit is basic, with no MP3 (unless you have an '05 model), no RCA outputs, no USB, etc, so already its suitability as the basis for a good sound setup is diminished. If you are willing to install an aftermarket head unit with faceplate, then you will be better off, but then it sticks out like a sore thumb on your console. Then theres the issue of running cables, opening panels, mounting amps, etc, which in a solidly put together car like the e46, is a mission.
Its not impossible to install a good sound system in an e46, just that if you DIY, then be prepared to put in alot of work, or if you going to use a fitment centre, then be prepared to shell out. I have replaced the speakers and tweeters in my car with good quality Pioneer units after a standard rear speaker popped. To be honest the increase in overall sound quality has been minimal, same crappy bass response, although it is much better in the clarity department and at high volumes it doesnt sound strained.
I have decided to leave it be, and just ensure that the next BMW i buy has a factory upgraded sound system.
I curse BMW for the standard sound system in the e46, especially when you compare it to the Mercs and Audi's of the same period....
