So you think the noise is originating at the speaker itself? Have you tried swapping the speaker cables (right swapped with left, either at amp end or speaker end) to see if the sound moves over to the opposite speaker or remains with the same one? If it is indeed in the speaker, the crossover would be the first place I'd look if it were a sound as you describe, but if you haven't swapped sides yet I would not assume it was in the speakers.
Merlin Tsm Static/ crackle from right channel
I have isolated to the one speaker.... just short of shipping back to Bobby.... What could have happened?