OK just replace the Papsts with 2 Panaflo L1As at 9 volts (lowest voltage my Nexus Fan Controller will give with fans of this power rating). All I hear now is the sound of air moving
Apart from..... the Neo2 Platinum NF3 chipset fan
But since I am going to replace this board soon with a DFI NF4 Ultra-D I'll live with it.
Looks like the postion of the NF4 chip on the DFI board means it will be a ***** to fit a w/b to.....