Are you in some place that blocks access to google docs? It's a detailed breakdown of every speaker in the car with specs, measurements, and performance graphs I measured with a calibrated microphone and some speaker testing software. It's intended as a guide for anyone who is thinking of replacing any of the B9 B&O speakers.

In my car I've replaced the subwoofer, front door woofer, front door mid, and rear door woofer.