I might be better off with that..
It's mainly the noise why I want to swap them as my electricity is free.
go for:
Fan Speed 10
Start Voltage 0.635 / 0.635 / 0.635 / 0.635
Max Voltage 0.64
with the above voltage settings, i got the fan reported at 6%, it's on auto and ambient temps ~23C
I'm already using fans at 6 atm. With even higher voltages.
I have ordered an Noctua NF F12 Industrial to try if it makes any difference in noise or if the case is the problem.