Noise Level Results
Increasing fan size has its advantages, even if it delivers less static pressure. Here we saw raw RPM winning over with more airflow. The bonus is that these fans at stock levels are some of the most silent fans I have used with a 24dB rating at roughly 750 RPM.
Even with full power to the NF-A15 PWM fan, they are barely audible, and you have to be within a foot or two to even hear them.
I had to take the reading a couple of times and I even changed the battery of the measuring device to be sure the 37dB rating I was getting was in fact correct for these fans.