PostmanPot
Honorary Master
What temps are you running at?
Mine are all inbetween 40° and 45° with a 120mm fan on 3 of them and a Vantec VTX on the Raptor - yet it still sounds like an anvil in gravel when writing or reading from the drive.
That seems a bit hot. My 3 HDDs run between 28'C and 35'C with 1 x 80mm fan blowing at them from the front of the case. Case is a relatively cheap Chenbro Gaming Bomb.
Not sure about Raptor average temps though.