I've been looking into getting a fan controller but im not really sure on the specifics if anyone can help me out. First, does it get the temperature reading from the motherboard or are there external sensors or sensors on the controller. Second, does the controller plug into a normal fan plug on the motherboard and if so wouldn't it be a problem when the motherboard turned down the fan voltage which turned down the voltage to the controller? I've been thinking of getting this one unless anyone knows of a better one that's not to expensive.
If you have fans that are attached to motherboard headers, they can be controlled with a free app like speedfan, or by motherboard bios settings.
Even then, I prefer to set my fans at a constant speed. I find that it is much less annoying to hear a constant drone rather than a constantly changing noise.
If the parts occasionally get a bit hot, so be it; they are built to take heat, and protect themselves if things get really hot.