I have replaced both speakers of my Mac Pro A1398 Mid 2015, on three (3) times. Still it keeps on bursting the edge of the speaker - rattling sound. I THINK APPLE SPEAKERS ARE DEFECTIVE FROM THE TIME OF MANUFACTURE. I have ordered another set this time from Ali express. Last replaced in December 2017. Last pair bought from ifixit, it lasted for 6 months - longest period it lasted. Now again rattling.