Just got a Corsair Obsidian 450D case and well it's a great case the stock intake fans are extremely loud, I'd say at least 35 dB. I've been trying to find some high quality PWM fans to replace them. Turns out there aren't a lot of airflow PWM fans. One fan I have is a Fractal Design Venturi HP (high pressure)140 fan on my CPU heatsink. Now, I know the difference between and purpose between a static pressure fan and an airflow fan but would it really hurt my cases cooling capabilities by replacing the stock Corsair AF-140L fans with these Venturi HP fans? If so, what are some equally quiet (you literally can't here this fan, even with the case open and being right up next to it) PWM controllable 140mm airflow optimized fans I could throw in the front of my case? Preferably black/grey, or dark colored.