02 745li and of course the dealer wants to replace the Logic 7 system for 1600. However, my question is does anyone know if these speakers are hooked in series? The reason for the question is a mechanic yesterday stated the speaker on my drivers side rear door and the center channel speaker center of dash by security light needs replaced. Acoording to him, he thinks if these are replaced my system may work. Now, I only get some scratchy sound out of the drivers side column speaker. Also, does someone know where I can get a electric diagram of this system? Thanks..