Thanks. I tried that a year and a half ago when I had a problem with the crossover, but I never heard back from him. I ended up fixing it myself. Besides, I bought the cab used.
So today I tested the speaker by gently pushing down on the cone, and I heard a crunching sound. So I thought it was blown. I took it out, tested it again, and heard much less noise. Put it back in, and it seems to work better now. However, the original buzzing/rattling sound is not totally gone. Its much quieter and higher pitched. It only makes the sound when I crank it and play hard. It's not a normal speaker break up sound. Does this sound like a blown speaker? Or is it something else? I'm pretty sure it's not a problem with the baffle or bracing.