Nope, just you. My R5 is perfectly silent. Check the hinges. That door is designed to be 'rehinged' on the other side. It's a sweet little gimmick that'll let you pick which way the door opens. When the door is open, there's stress on the hinges (gravity) which will dampen vibrations from the intake fan(s). If the hinge is even slightly loose, when you close the door, the hinge is no longer stressed so is now free to vibrate.
Only other option I can think of is when the door is closed, it's not hitting the bumper stops right, so the door itself is on a plastic-plastic meeting with the case.
Either should be a really easy fix.