JustinThyme
Can you explain what's the main idea to get working noise cancellation that you describing?
D5 pumps themselves vary in noise and usually an exact pump/top unit with its exact mount needs to find its most comfortable running speed (though yes, software controlled pumps are best while looking for most comfortable and less resonating speed). But in any exact pump/top unit, good anti-vibration mounts are key to quiet operation. Any pump, even the best ones, that is hard mounted to the case - will be loud and create much annoying resonating sounds from the case or panel its mounted on. Even most known-good antivibration D5 pump mounts, e.g. EK-Revo or Aquacomputer ULTITOP, though being good, are not enough dampening for a demanding owner. I recommend additional rubber thumbs for any pump mount out there.