2 way Headphone crossover update

Hallo i want to construct a 2 way speaker crossover but i dont know how, im new to the electronics construction.The crossover for my application will be not for a speaker but for a 2way studio headphones from the 70s can anyone help me understand how to construct it and how to calculate and identify witch capacitor or coil to use for specifiec frequency ranges? and where to cuttof the freq ranges for smooth and natural sound?