Function keys on CM Storm QuickFire Rapid

[llo...@gmail.com]

OS X version: OS X 10.11.6

Karabiner version: Karabiner 10.22.0

Mac hardware: MacBook Pro

Keyboard: CM Storm QuickFire Rapid

I'm very new to Karabiner and non-Mac keyboard, but I haven't been able to figure this out with some searches.

I enabled just one option in Karabiner: "For PC keyboards: Change f1...f12 to brightness control, ....". That did work and pressing F12 changes the volume. The problem is that pressing Fn + F12 doesn't work as F12 anymore (also changes the volume). Is there a way I can have pressing the F-keys do the media control action, but pressing Fn+F key does the function key?

Thanks.