Linear Response was the aim of these rare 'speakers : whatever the output level, same frequency response.
Through CAT and laser-holography, the heat & pressure-formed cones and stiffening coatings were to allow more linear motions...
The drivers are made of a mix of cellulose, mineral and metal fibres.
Formed by 2 separate enclosures with the top being able to rotate on the drivers' magnet axis.
The LS-1900 is a very rare item, coherent in Kenwood's then completely incoherent mix'n'match of market-specific export-only and Japan-only items, lineups and ambitions...