I would say again, Speedfan...
because it does
work, and is
for this type of issue... if you've not got it working then you're most likely simply not creating a profile correctly!
Above I already made another two suggestions, but let me hightlight one of them for you again with this useful link to a fan controller review
for you to read.
When I have had noisy fans and there's no way for them to be attentuated then I've always considered doing three things, firstly - get as quiet and large a fan as possible, secondly, ensure your cooling fins/matrix are dust free and that any thermal paste is properly applied to the CPU or the chipset in question, and finally... there is always the technique of undervolting, whilst not always desirable - it can drastically reduce noise when a 7v or 5v modded power link is connected to a 12v fan...