Help Fan Speed Sabertooth X79

[T3DDY]

TL;DR
Does anyone know if it's possible to mod the bios of an Asus TUF Sabertooth x79 to allow lower fan speeds than 60 percent.

Hello,
First of all thank you for taking the time to read this.
I have an Asus TUF Sabertooth X79 Motherboard and recently installed some new Case Fans (Arctic P12 Max). Unfortunately they are running way to fast and loud. The fan speed bios options only allow me to set a minimum fan speed of 60 percent. In my infinite wisdom I decided to look into bios modding ( I don't know anything about this ) instead of buying a PWM Fan hub Controller thingy and now I am to proud to give up. After quite a bit of research I found out that I have an AMI Aptio IV (4) uefi bios and that there's a tool for Configuration. After some more Research I found a thread on this Forum that linked me to a Download of AMIBCP 4.5, but not even this tool allows me to set a fan speed below 60 percent. I don't know where to search for Information anymore. Does anyone know if it's possible to mod the bios to allow lower fan speeds.

Thank you in advance.