The schematics shows the electronics that is in the speaker box.
At the top you find high voltage source. It is based on the classic multiplier circuit. The 400 MOhm to ground removes the charge slowly when power is off. It also gives a more stable voltage and a little lower voltage that reduced a tendancy to arc.
In the middle left is the step up trafos. Four toroid mains voltage trafos in series giving a step up ratio around 150.
In the middle right is the segmented ESL including ladder resistors.
In the bottom you find connections to the bass speaker.