How to Measure a Voice Coil

To order a new voice coil, measure your original voice coil for this info:

Inside diameter (ie: 1.518″, 2.018″- use a caliper)
Length of former
Windings width
Layers (ie: 2 layer single, 4 layer single, 4 layer dual
Impedance

measure length of former

measure inside diameter of voice coil former

measure winding width