We measured the noise output of our entire system from a distance of 1m while the CPU cooler's fan(s) operate at 100% (indicating the maximum noise output).
Lower noise levels can be achieved by utilising the Phanteks PH-TC90LS CPU cooler's 4-pin PWM operated fan with a dynamic profile.
The 2,500 rpm Phanteks PH-F90 fan is slightly louder than the NF-A9x14 model used on Noctua's NH-L9i and noticeably more audible than the unit on Intel's Core i5 3570K heatsink.
Lower noise outputs can be achieved by utilising the PH-F90 fan's PWM operation, but not via a low-noise adapter as Phanteks decides not to supply one.