I have an Asetek 550LC, which is the OEM Corsair H60. There's tons of topics/videos about how these Corsair Hydro pumps buzz and there's no definitive solution. Some have RMA'd multiple times with the same issue. Some were able to undervolt the pump with success. My current setup is:
MSI Z170I Mini-iTX motherboard
Pump in CPU_FAN header (0.2A)
Radiator + Case fans in SYS_FAN header via 3-pin splitter (0.6A)
I've tried controlling the CPU_FAN header with the BIOS, but it seems it only controls with 4 pins, because it stays at 100% regardless of what I put the curve at. I've tried switching fan headers, then my fans go full blast in CPU_FAN, so I can't hear the pump to check anyway.
One thing to note is that it seems the buzzing loudness comes and goes. There's always a light hum, which is fine. This isn't air bubbles, it's definitely an electrical sound. Any insight is appreciated.