I received the IPC Queen fan and unfortunately I found it to be louder than the Cofan.
I did find a way to make the Cofan quieter. Someone suggested removing the label on the Cofan, removing the rubber plug, and adding an oil/grease mix. I did that but observed no real change to its volume.
Then I decided to push the fan blades off their spindle. Using both thumbs through the housing the blade assembly slid off revealing the sleeve bearing. I oiled and greased it, ensuring the oil went between the sleeve bearing and the spindle. I then reassembled it by pushing the blade assembly back on the bearing and mounted it back into the Tivo using O-rings on both sides of the screws to isolate the fan from the box as much as possible.
Now the Premiere is quiet. I can still hear the fan moving air but no other obnoxious fan sounds so that's good enough.
BTW, I tried pushing the fan assembly off the IPC Queen to lube it as well but it simply broke,