System Noise
Here's where things get really interesting. SilverStone's Heligon HE01 offers great cooling performance, but it also has a tendency to get frustratingly loud. be quiet!'s Dark Rock Pro 2, on the other hand, sacrifices a bit of of performance but in doing so happens to be one of the quietest high-end coolers on the market.
The Phanteks PH-TC14PE slots in between. The bundled PWM adapter does a good job of keeping noise in check, and the cooler is neither silent nor loud; it's quiet enough when idle and though it's clearly audible under load, it isn't too obtrusive.