make a fan controller?

[jaibot]

hey,
so i have 4 high speed panaflows on my rad and they are extremely loud. They have succeeded in driving me, my family, and friends on vent absolutely nuts.
So i would like to build a fan controller to keep the noise under load.
I dont know much about electricity, etc, but from what i can gather resistors resist voltage depending on how many amps are going through them and diodes always resist a set amount of volts. Therefore i think i would think that i would like to use diodes in my controller.I would like three settings, full 12v, maybe a 9v, and maybe a 7v or 6v. I guess i could make my own switch, or maybe get one, but i am not sure what to look at.
Furthermore i was wondering if heat will be an issue. THe diodes will be resisting 1v (about) each, with 2a going through them. How much heat will this generate, and should i make heatsinks for the doides.
In summary
-brush me up on specifics of resistors, etc
-what to do for a switch
-how much heat will diodes give off
thanks in advance for your help, it is much appreciated

 

[Krispy Kritter]

You can buy them for about, or not much more than the parts will cost you.

Check out: http://www.frozencpu.com/

Unless I'm mistaken, a basic one uses just switches and supplies the voltages already present on a molex. Three settings, off, 7v, 12v...no resistors or diodes necessary.

 

[tuberc]

If you just wanted to reduce voltage to the fans install a resistor in line on the fan cable, obviously its the easiest way but non adjustable,
just buy a handy fan controller like the one I just got for my project, its cheap and better quality that the average person could ever make.

http://hardforum.com/showthread.php?t=1363417

 

[Mystic-Micro]

Could you not just switch the wires from the molex adater if you wanted no control over fans speeds?