In our noise level tests we switched off all the case fans and replaced the AMD Radeon HD 7950 graphics card with a HD 5550 passive model so were just taking into account the noise generated by the cooler fans themselves.
We measured the noise level with a Digital Noise Level meter at a distance of 1 m from the front of the system.
In this test, the acoustic performance of the NZXT X60 isn't that great although it is no worse than the H110 in ‘Extreme' mode. With the fans running at maximum speed, the cooler was excessively loud, though.