Directional loudspeaker, has contracting main membrane and resonating auxiliary membrane arranged in dipole housing, where main membrane produces ultrasonic pressure in housing inner area that is provided with rearward or lateral openings

摘要

The loudspeaker has a contracting main membrane (1) and a resonating auxiliary membrane (2) that are arranged in a dipole housing (4). The main membrane produces an ultrasonic pressure in a closed housing inner area (3) that is provided with rearward or lateral openings. The auxiliary membrane is moved based on an inner pressure for oscillating the main membrane, where physical characteristics of the auxiliary membrane control an overlapping of pressure and dipole radiation.