A word of caution. I looked into this and it seems extraordinary complex to design your own speakers. Even build them seems tricky. Here is a German shop that

A word of caution. I looked into this and it seems extraordinary complex to design your own speakers. Even build them seems tricky. Here is a German shop that sells kits: https://acoustic-design-online.de/de/ https://acoustic-design-online.de/de/ They had once kits to build your own electrostatic speaker (warning, high voltage, danger!): http://silberstatic.de/ http://silberstatic.de/