For anyone who doesn't know, the NF-F12 iPPC 3000 PWM is a cursed abomination that sounds like a drone motor at full speed while blowing gale force winds, and makes this horrendous B-flat whine at low speeds that sounds like a vuvuzela.
And the sad truth is that there's a sweet spot where, beyond that point, adding more airflow gives you diminishing returns-- and that spot is about where the normal line of noctua fans are.