Was the fan definitely bad with your HX1000? I just finished doing the same thing to my Ultra X3, since I was getting some noise from it. Once I took everything apart, I determined that the unit was packed so tightly that there wasn't any vibration isolation between the fan and the rest of the PSU. The fan is pretty quiet, it just wants to vibrate when it contact with anything solid. I stuck a few pieces of foam on the bottom of the fan frame, and now the noise is gone - just a bit of an air whoosh at idle.
__________________ i7 2600K | ASUS Maximus IV GENE-Z | GTX Titan | Corsair DDR3-2133 |