At the moment my desktop is rather noisy, I would like to know whether I'm better off investing in either a fan controller or replacing the stock intel heat-sink that I currently have installed. My CPU runs at about 30-40 degrees so there's no issue with temperature. I also have 5 case fans installed but I don't think they're so much of a problem. Currently it is just too loud, any advice is gratefully received! 
Thanks in advance, Jack
Specs are as follows:
-Intel i7 (3rd gen)
-Asus P8Z77-v lx board
-Corsair 550W PSU

Thanks in advance, Jack
Specs are as follows:
-Intel i7 (3rd gen)
-Asus P8Z77-v lx board
-Corsair 550W PSU