motor speed controller

Does anybody know if this will work for controlling the speed of fans?

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

I assume it should, all the fans we are using are the cheap inline duct fans, they are really loud and Im hoping that router speed controller can be used.

I have also found:

http://www.bghydro.com/BGH/itemdesc.asp?ic=AFAGS&eq=&Tp=

Looks exactly the same as the one from harbor freight but is half the price. Is there any differences between these too besides the corny "speedster" name?

thanks for any help guys

Yes. It the same as you find in the hydro stores.
I bought 4 from Harbor Tools.

Have you been successful with quieting fan noise? Just wondering cause Im a little worried it may also not provide enough power for ventilation. I know the cfms are reduced, but by how much? Im pretty much asking...am I making these fans useless just to quiet the noise they make?

They have those at harbor freight, sweet. Just online or at ur store

I don't use them to decrease energy useage or to muffle motor noises.
I turn down my intake fan slightly for negative air pressure in my tents.

My fan (410cfm) seems to become louder when I decrease its power.
I think I read it had something to do with harmonic fluxuations.