BMW 328Ci Speaker Size

Front Kick Panel Speaker

Rear Side Panel Speaker

Front Door Panel Speaker

Rear Deck Lid Speaker

Cargo Area Speaker

BMW 328Ci Speaker FAQ

What speakers should I replace first in my BMW 328Ci for the biggest sound improvement?

Replace the front door panel 5.25 inch speakers first. These handle most of your music's frequency range and sit closest to your ears. The 328Ci's front doors typically accept 25-40 watts RMS component or coaxial speakers. Component speakers separate the tweeter from the woofer - you'll get clearer highs since the tweeter can be angled properly. But coaxials work too if you want simpler installation. The factory speakers probably peak around 15 watts, so any decent aftermarket option should sound noticeably better.

Can I upgrade the kick panel speakers in my BMW 328Ci without affecting the tweeters?

The kick panel setup is tricky because you have both 2.5 inch midrange drivers and separate 1 inch tweeters in the same location. You could replace just the 2.5 inch midrange speakers with something handling 20-30 watts RMS. Look for drivers that reproduce 200Hz to 5kHz effectively. The existing tweeters might stay functional, but... the crossover network probably won't match perfectly. Better to replace the whole kick panel system as a component set if you want proper integration. Otherwise you'll get weird frequency gaps or overlaps between the old tweeters and new midrange.

What's the difference between installing coaxial vs component speakers in my BMW 328Ci rear deck?

The rear deck lid accepts 6.5 inch speakers rated around 20-35 watts RMS. Coaxial speakers put the tweeter right in the center of the woofer - easier installation since it's one piece. Component speakers let you mount the tweeter separately, maybe angle it toward your head instead of pointing at the ceiling. But in the rear deck location, coaxials often work fine since rear speakers mainly provide fill and ambiance. The 328Ci's rear deck placement isn't terrible for imaging. Component sets cost more and need extra wiring for the separate tweeter. Unless you're building a serious system, coaxials handle this spot adequately.

Should I bother upgrading the small 2.5 inch rear side panel speakers in my BMW 328Ci?

These 2.5 inch rear speakers probably only handle 10-15 watts and focus on mid-frequencies. They're not terrible but replacing them ranks low priority. The small size limits bass response below 150Hz anyway. If you do upgrade, look for full-range drivers rated 15-25 watts RMS. Some people disconnect them entirely when running a good front stage. The rear side panel location in the 328Ci doesn't add much to soundstage width. Save your money for the front doors and maybe the rear deck first. Unless the factory ones are blown or buzzing, they're adequate for background fill.