What is the difference in the voice coil of a tweeter and a subwoofer?

Question

I am trying to build an audio system from scratch and want to specialize each of the parts.

Answer 1

The subwoofer coil will be bigger just like the speaker itself is bigger.  Because it's for low frequencies it doesn't need to move as fast as a tweeter.  A tweeter is smaller and lighter to move faster.  

Make sure you compute the impedence correctly.  You'll need to know the inductance of the coils in the magnet to do this.