TC rear disc noise

mine squeaks and chrips all the time. one day i had the rear jack and was tapping with my hand various spots to see if i can find the noise and when i started tapping the wheels, it made the chirping noise. i would like to know what causes that. to this day i have not figured it out and hopefully we can soon
 
I thought mine was the wheels too because one of mine was warped a little.I got a new set of cobra r's but it still made the same noises after I put them on. Some days they chirp worse than others.I've tried just about everything. I'm stumped!!