4010 ender fan duct silent and quiet

thingiverse

I am trying to make my stock 4010 fan a little bit quieter. I already tested with the straight duct and has a good results, works as a muffler, the noise perception show a good result... The negative bellmouth buffs the noise more, but the noise perception has not good results... The outsider duct can be mounted directly on the fan housing, it is not necessary to print the first duct... Please, I would love if you can test in your printer and share the results with me :) PS: I decided to mount the fan outside of fan housing to be easier to make some tests with buffer materials as foam...