Red 4 To WD4003FFBX whistling


I just bought 2 RED PRO SATA HDD 2 days agos
I use them in Raid Mirror in a be quiet case ( hdd cage with Decoupled installation )

The both HDD are whistling ( high note ) all the time… it’s really annoying.

I tried only one disk, whistling too.
I tried both on separate power cable, whistling too.
I really dont know if both are oki, if it’s a manufacturing problem or something else.

Does someone have same problem ?