So I was using a fan grille that I had found on here, and printed to make my printer look cooler. However it made my hot end fan very noisy. I realized it was causing the fan blade to chop the air, which kinda how air raid sirens work.
It also caused the fan to speed up, which means less air flow.
Don't believe me?
Cover the intake on your hair dryer it speeds up, and the air flow stops. It's like spinning in a vacuum it's not doing as much work but it's getting the same amount of power.
The base plate is slightly bigger than the fan will be, but the id should be close to the id of the fan housing. The holes are slotted for ease of installation The grille is minimal and is raised up above the fan so there's plenty of air for the fan to move, and no chopping.
I don't have decibel numbers, but when I put it on I was like OOOOOOH OK.
Its quick to print even though you have to use supports.