Computer fan power content for ac dc outlet?

I'm not using it for a computer lol I'm trying to put them on the back of my entertainment stand so I can slide my xbox in the cubby whole and have air flow tats why I need converter!
 
I've been thinking I was just gonna get a 12v usb port and use the usb adapter instead of outlet and probably gonna have to use a 5v to 12v usb booster right? Not sure if that'd work.
 
It would work, but I think it would be simpler to just get an adapter, unless you are not comfortable with soldering. You can just strip the wires and wind them together. You can then use a glue gun to insulate it.

Still, I'd highly recommend soldering it together, because that method is really a last-choice.