I'm almost positive I've seen those drivers that are being used on the cutting head before... They look like.... yeah: Waterproof audio transducers, make by a

I'm almost positive I've seen those drivers that are being used on the cutting head before... They look like.... yeah: Waterproof audio transducers, make by a company called PQN and designed for hot tub sound systems. https://www.ebay.com/itm/174285036157 https://www.ebay.com/itm/174285036157 I guess that is one way to get a premade, high-displacement, powerful enough voice coil in an easy to mount package at a normal speaker impedance. Genius.