Apparently I got the wrong idea of what you're looking for. We seem to be arguing whether or not fans make measurable noise, or if passive is better than fans to get less noise. I totally agree with what you are saying on this. My fanmate recommendation came because you seemed dead set on having fans, throttling them, and 300-1600 rpm was mentioned. That didn't make any sense to me. I totally agree that passive is better than fans, and that fans do in fact make measurable noise. I was just trying to give you a better option that anything that might jump to 1600RPM while you were in the middle of trying to record something important, which is what it seemed you were determined to do. If you can run passive, clearly go for it. If you must have a fan, my basic recommendation is simply to hard set it at a "tolerable" noise level and let it run, so you don't take any chances of it jumping in RPM and destroying something you're working on. That's all.