Any advice for reducing drive noise?

I've recently upgraded from a node 304 to a CX4712 which is my first rack mount case. I'm really liking it so far apart from the hard drive noise. The general sound of the motor is the same as before but when they read/write any data the sound of the arm moving seems to be amplified by the case and it's much louder. Has anyone got any tips on reducing the noise?

Thanks!