I was thinking about making a mod for an external fan that is attached to the bottom plastic grill, blowing air into the 360. Got a few basic questions.

My idea is to use two 80mm PC fans, attached to the grill and powered by the USB port.

I know that USB is 5v - so is it possible to power these fans using that (standard 12v fans), or would the low voltage be an issue? Should I wire the fans in series or parallel? I wasn't too good at electronics in school.

I know it would be much better to use the 12v source on the motherboard but I'd like to be able to do this without voiding the warranty..

Any idea's/ suggestions greatly appreciated.

Oh and I could use both the front USB ports (5v a piece I'm guessing) because I only use wireless controllers anyway...

Yes 5v would work and you'd wire them in parallel. You can also splice into the PSU line to get 12v, this won't void your warranty.

Cool. Would it make any difference if I used LED fans over regular fans? I guess the extra power consumption would be nominal.

Shouldn't make any difference except the led's might not work since it's expecting a 12v power source.

Cool.

One more thought. Would it be possible to combine two ports to make 10v?

No.

Ahh ok, thanks MickRaider! You've been most helpful.