i just installed one today, i set it up with the manual control the little pontetiometer thingy, i had to figure it out ma self coz the instructions jus told me how to do the lights on the coolmod, and a bit bout the 3 modes u can put the smart fan in. i chose the 3rd mode which is manual fan control.
on its lowest settin the fan is superbly quiet. my HDD are louder!!, (but there are two of them)
ok ill admit, its abit loud on full whack, and with the ccase side off,(i got a shoddy case with no airflow whatsoever) it sound like a industrial grade fan, but it dont half get the job done.
u may have just installed it in fixed mode, which is full speed at all times.
dont bother with the little temp sensor, its fiddly to install an busts if u put too much pressure on, and goin on how much i had to push jus to get the clip on, im glad i never coz i reckon it would be broken by now.