Been very happy with my NH-D14 ever since i build this pc, but recently i have been trying to locate an annoying low humming noise comming from my pc, it seems like it is the NF-P12 fan aka the outer fan, tried running with just the middle fan aka the NF-P14 and the noise goes away.
Im guessing running with just the middle fan is perfectly fine? I have a 4670k running at stock right now, thinking of just running with the middle fan until i get a replacement.
Try to move the p12 fan to the other side and see if that helps.
If the p12 fan is now blowing air on to the cooler move it so it sucks air out of the cooler instead or the other way around if it sucks air now.
Right now i only have the P14 running and the P12 shut off, testing the difference in temps, seems pretty much no difference at all right now, but might give it a go and see if pulling air with the P12 is better, i guess the noise can come from one fan pusing air into the other?