摘要 |
Loudspeaker ROTOSUB including a motor driven rotor provided with wings or blades that are adjustable to their pitch and where the pitch is modulated by a signal, in particular electric, corresponding to a desired sound. In particular at very low frequencies the loud speaker rotor that during each sound wave length has time to rotate many revolutions can move large amounts of air that in turn can provide a large air and sound pressure. The technic is based on the generation of sound waves by modulating the angles of the wings. At low frequencies the rotor has time to rotate several revolutions per signal cycle which provides increased pressure. Since the wings can be pivoted in arbitrary angles the pressure can be controlled in the desired way. |