Tabletop Vibration Audio Device (TVAD) Digital Speaker.

NDR Tabletop Vibration Audio Device (TVAD) digital speaker that uses, instead of diaphragms, a tabletop (wood, glass, plastic or any solid sheet) and such, on which it is placed, to render sound. The device mainly uses a super magnetostrictor that extends and shrinks in line with magnetic field changes. The actuator converts input sound into vibration and conveys it to the tabletop so it renders sound. TVAD has no moving coils, cones or surrounds, which makes the TVADS extremely reliable to withstand abusive environments and maintain a long service life.