I only heard or noticed the noise WITH THE BELT OFF while I was changing a pulley. I rotated the pulley back and forth by hand and could hear a clunk. The clunk sounded like the rotors trapping each other.
I was only wondering two things. First, if too tight of a belt would put unwanted stress on the s/c bearings to the point of causing damage. Secondly if it's normal to hear a little clunking when rocking the pulley by hand.
I did find out elsewhere that you should only run too small of a belt for a track run, and then put the right size back on for daily driving.