Brand new professional motor sounds different.

[Raceman17]

I have owed 3 different models of the Phantom 3 series quad copters. All of the motors sound the same when you free spin them with your fingers. They kinda have that high speed pitch sound to them. I received a new professional model in the mail today and one of my motors sounds completely different. You can still feel the different magnet position as you rotate it slow but if u try to spin it fast with your fingers the sound is a much lower pitch. Kinda like a bearing issue. Has anybody seen this type of behavior on a new out of the box Phantom?
Thanks