This type of dual voice coil driver/motor topography is much different that the typical dual voice coil driver, say for for car audio, where the dual coils are wound together on the former, have separate lead outs for multiple impedance options with two sets of terminals and share the same voice coil gap.
This is in the family of "Differential Drive" transducers that have two voice coils wound separately on the same former and have two voice coil gaps.
The idea is to separate the travel of each coil and magnetic field into two separate entities. When the one voice travels toward the direction of the opposite gap, a braking force is applied to that coil while the opposite coil is charged to move in the reverse direction. This is said to reduce motor induced distortion. Ferrite magnet models have a third coil that sets in between the drive coils and acts as a magnetic braking system to help stop the movement of the entire coil assembly before it reverses direction.
Hope the explanation helps. Here's the tech note on the technology.
https://www.jblpro.com/pub/technote/...-33%20rev3.pdf