[phide]

By floating, I'm referring to using flexible stand-offs, in the same fashion as recording studios and movie theatres float floors and ceilings. In a typical studio, at least the floor and ceiling have no direct contact with the foundation, either by "hanging" (suspending a ceiling with a series of cables and wires) or using Z-shaped suspending metal brackets (in the case of the floor). Instead of a Z-bracket, or other type of device, however, I could use small rubber cylinders. The box that contains the pump, probably comprised of no less than 1/2" maple or other suitable wood, and sealed as completely as reasonably possible, would have no rigid contact with the outer box, which would be just as substancially thick. This all-encompassing box could then be floated in a similar fashion from the case. The question is whether or not the motor will have any issues with the additional heat typically dissipated by airflow. But since the coolant is the main avenue of heat dissipation, I imagine the casing will just come to a sort of equilbrium, and the heat typically expended by the casing would just get dumped entirely into the coolant.

The D5's whine is fairly high frequency which is actually ideal in this situation: the higher the frequency, the easier it is to attenuate without something as excessive as multiple layers of sound absorptive material. Depending on how well one can seal it within the inner box, the total attenuation could probably be as much as 30dB.

Or, yeah, I could just drop my D5s on eBay and get a couple DDCs with Radiical tops, but where's the fun in that?