Quote Originally Posted by mushaboom
im assuming this s true for most inline fans of quality, but for my vortex 6" 465 cfm model any time you turn down the speed it buzzes. its not too bad of a buzz until you go under about 75% power. below 50% it buzzes like crazy. i think your best bet is to just get an appropriate size fan for your areas size so you would not need to use a speed controller. (by the way speed controllers can be found at harbor freight for about 13 bucks, same controllers that hydro stores sell just not with a brand on it.)

have you thought about using an inline duct fan from a hardware store such as lowes? theyre pretty cheap and they should get the job done just as well. ive never used one myself but they defintely look like a good way to do things on the cheap.
Mushaboom,

I don't use Vortex, but have helped a freind with his two- 1- 6" and 1- 4". The 6" is on a speed controller running abt 80-85% of full speed, and is real quiet. While the slowing the fan a little we gained a great amount in "air noise" reduction while mechanical noise was about the same.

This buzzing sound that your fan makes; is it a electrical sounding buzz or a mechanical buzz?