We measured the noise output of our entire system from a distance of 1m while the CPU cooler's fan operated at 100% (indicating the maximum noise output).
Lower noise levels can be achieved by utilising the 4-pin PWM operation of the Cooler Master Seidon 120M CPU cooler's fan.
Acoustic performance isn't a strength for the Seidon 120M – the cooler is loud at 100% fan speed. We would wholeheartedly recommend making use of a PWM profile which allows the fan's speed to be decreased at lower CPU temperatures.
When not being overshadowed by the fan's noise, the Seidon 120M's pump unit is actually very quiet and inaudible over low speed case fans.