750D bottom intake vibration

Hey everyone. I recently purchased a 750D, and I'm having a little bit of trouble with the vibration coming from the bottom fan mounts. When I crank my AF120 RED LED fans to 1500rpm, they vibrate the case and gives off an annoying sound. I then thought that I should take some of the rubber washers that came with the case, and put them under the fans (Case --> rubber washer --> Fan). This didn't fix the issue. What could be a way to fix the vibration and sound?



Also, any good type of after market dust filter for the bottom intake? Ive seen some really cool ones that Silverstone makes, but im still not sure