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.

Removing the metal "grill" on the front of the 600T and 650D chassis (not the metal mesh over the filter) is a popular mod for these cases to both reduce noise and to improve airflow. It also allows mounting thicker fans without moving the HDD cages, such as the CM Megaflow 200mm x 30mm (the fan itself has to have the rear mounting ears removed), since the fan can be mounted with the mounting flange outside the chassis and the fan body inserted into the resulting hole left by removing the "grill". I cut mine out using a Dremel tool with a straight cutting bit in a compass jig designed for the purpose. I had the case stripped down at the time so I didn't have to worry about metal chips getting into anything they shouldn't (something I STRONGLY recommend before cutting metal on a case, no matter the technique used).

 

While the two cases are no longer in production, this is something Corsair should have done to begin with instead of punching the myriad round holes for a grill. Even a punched hexagonal grill would have been much better than the round holes.

my Corsair C70 makes the same awful noise if you remove the filter which I need to for better air flow. I pull my front cover/panel off then reinstall it starting from the top and leave the bottom out about 1/2 inch and the noise is gone. the C70 has small holes in the front, I wish it had oval/bigger holes like the 450D, my friend has the 450D with the same Noctua fans I have and he has no noise.

You're probably right, but please remember the 600T and 650D were among our very first cases. It's an ongoing learning process, it's a minor miracle those cases turned out as good as they did in the first place. ;)

 

And, in my not so humble opinion, the 650D was one of your best cases ever.

We weren't aware this was an issue, but the tip is appreciated nonetheless for the 600T holdouts. :)

I have two 600T cases so I did some research. The frequency of the hum is independent of both speed of the fan and the distance of the fan to the metal mesh. That means it is a standing wave caused by the vacuum created by insufficient airflow becuase of the small size of the holes and the diameter of the fan. The metal case itself vibrates acting like a guitar's sounding board but not true with the fan (I tried pushing in the fan's hub center with a ballpoint pen (a bearing surface) and that did not make any difference.)

 

In order to get rid of this very obvious, annoying, and avoidable resonant noise (along with the vacuum created by restricted air flow), THE DESIGN OF THE MESH MUST BE CHANGED.. The mesh must be made less air restrictive to let in more air flow. The case's mesh holes look pretty but are defeating the purpose of them, sufficient air flow to cool the case. Corsair needs to have a design team use a resonating template like 1/8 temperboard and try different configurations of slots and holes until both the restricted airflow and the resonating hum is fixed.

I am not sure why the Corsair Graphite series 600T midtower case (my two are white) is "out of production" since it is still listed on the Corsair product pages and sold by Amazon as the "Corsair CC600TWM-WHT Special Edition Graphite Series 600T Mid Tower Gaming Computer Case". Besides the Vengence series looks like the same exact mesh pattern for the front intake air flow.