Hi, the front plastic bezel/panel on my antec three hundred two case vibrates (mech movement from hardware), and it's an annoyance. Tried putting rubber bands on the parts that snap into place, but that doesn't help.
Make sure that the drive mounting hardware (plastic slides) are properly seated on the drive, and make sure that they are fully inserted into the slot (you should hear a click when inserted).
If the drive is creating the vibration when properly seated, try removing the drive, and powering up the system just to verify. I have 4 hard drives, a DVD and BluRay player - no vibrations were detected on my system.
If it is the drive, there could be an alignment problem with the spindle causing the vibration - hard drives aren't silent, but they shouldn't emit loud vibrations...you might want to consider replacing the drive.
Ok, I've finally been able to check for the loud vibration's origin, and two of the hard drives were vibrating, due to not being seated properly. Then there's a vibration coming from the top-rear exhaust fan, transferring the noise to the case surfaces.