Got a set of db6500s about a week ago. They've worked fine until today, when one of the tweeters started making a rattling or buzzing sort of noise that went with the bass in the music. It happens unless the stereo is put at a pretty low volume. I looked at the speaker while it buzzed, and noticed that you could see that membrane thing under the grill vibrating profusely when it makes the buzzing noise.
Is there anyway to fix this, and what could have caused it?