My noise is definitely the differential but it is not enough of a concern now that I see others have the same small noise with light pedal pressure.

My blown speaker is the door lower right. I am ordering a set of 609CS Infinity for $130. From what I read they are a great improvement and if I am ripping apart the door I am changing them all to new ones. I also had one of the tweeters act up once in a while so they are all going... $130 is a good price for the 609CS...upgrade to our current speakers...comes with crossover too for adjustments.