@surfchina, nice res mount mod, I like that. I may be doing a fan silicon rad gasket velcro soft mount soon.
@surfchina and Oxzz, both you guys.
Never heard any high frequency sounds from my two D5s except when some air remained within the pump top while filling the loop.
Mostly the noises I heard at first were low frequency hum and rumble which drives me nuts so I isolated my D5 to complete silence using two EK UNI mounts and four 3/4inch sorbothane feet.
It’s not so difficult to isolate a D5 to complete inaudibility if you simply make certain that no portion of the pump or pump top make any hard contact with any part of your case or any other component part other than the isolation material you are using.
In my set up those isolation materials are the four sorbo feet mentioned above and soft tubing filled with coolant which also acts to absorb/isolate low frequency noise.
You have to look at what you are building, what components are in hard contact or hard communication, those components will transmit the noise energy and must be considered a single assembly when building.
In this second photo, my D5, EK plexi pump top, two monsoon fittings, and the AquaComputer thermal sensor are all in hard communication and are the “single assembly” that must be isolated. You also need to think of the direction of the forces, my assembly is simply resting on the sorbo feet and EK UNI mounts by gravity alone, no hard mounting allowed if you want absolute inaudibility.
That assembly does not make contact with any other component in the build except the noise absorbing sorbothane feet and soft tubing filled with coolant.
Does that mean my D5 is completely inaudible up to 100% power or 5000rpm? No, my set up in these photos is only inaudible up to 50% power or 3500rpm, but that’s fine since with the short “CPU only” loop I’m running I never need to use the pump beyond 35% PWR, above that speed there is no cooling benefit for the CPU.
For those with larger longer loops including many more components that need to run an everyday D5 rotational speed above 50% power, then more robust noise-energy absorption can easily be designed, moving to larger diameter sorbothane feet, OR getting the material in sheets and cutting it custom to fit your setup.
Sound expensive? It’s not too bad, The Sorbothane feet are a dollar each so $4. They make you buy a pack of 16, so save the extra 12 for the next build, I put 2 under the front of my keyboard, perfect for raising it up to just the right angle.
And the two EK UNI mounts work extremely well. The D5 housing slips down into the hole in the EK mount and none of the D5 makes contact with the mount since that would violate
the rules of noise energy isolation and transmit the noise.
These two pics show the sorbo feet "in action" and an overhead view of the single assembly that needed to be isolated.Edited by iBruce - 1/21/16 at 8:50am