So I'm on a Corsair H60 which has been a trusty servant but I've got a project to 100% silence my PC in idle and this thing gives off a noticable hum. It's an AIO water cooler, and in truth I don't mind going passive as long as the temps don't suffer. But aside air coolers, what would be the quietest (read: silent) AIO cooler for CPU? PS I don't want a small noise, I don't want a little hum - I literally mean genuinely inaudible. Any recommendations?