Need help to control fans

Solution
The motherboard only sees one fan because you use a splitter.

The motherboard can control each fan header, so if you connect multiple fans to the same header, through a splitter, the motherboard will control them as if they were one fan.
The motherboard only sees one fan because you use a splitter.

The motherboard can control each fan header, so if you connect multiple fans to the same header, through a splitter, the motherboard will control them as if they were one fan.
 
Solution
not for a splitter...as vexillarius mentioned, splitters dont allow for individual fan control. fan control is based on the fan header. there is 1 control per header. anything connected that that, is controlled as if it is 1 fan regardless of whether it is 1 fan, or 100 fans.
 
A solution would be a fan controller. Those bypass the motherboard altogether. You hook the fans up to the controller (which is usually mounted in a 5.25" bay) and the controller to the PSU. You can then control individual fan speed through buttons or switches on the controller.