Remove the front metal mesh on 600T case to get rid of resonance.

Folks, because of the lack of adequate size of the mesh holes on the Corsair 600T cases, any intake fan will create an annoying resonant hum. Since the top fan is an exhaust fan, it does not have this noise. NOTHING TO DO WITH THE FAN OR ITS SPEED The only solution is to remove the mesh. two ways to do it without making fine metal pieces floating about. Turn off computer and UNPLUG it. Remove front bezel (Optical drives need to be removed first). Remove the fan. Use a number one Phillips screwdriver to bend and break a few of the connections between the outside holes. I then used tin snips to finish the rest but you can continue with the bend/break technique. Use caution and gloves. Use a pair of pliers to straighten out any bent tabs of metal. Put a 200 mm finger guard protector over the hole, vacuum up any loose pieces, and replace the bezel and fan filter.

If you want to Dremel out the mesh, use a sheet of cardboard and keep the vacuum running while cutting.

No more resonant buzz.