Abstract: A panel-shaped loudspeaker includes a panel (1) and an exciter coupled to the panel. The panel is provided with two parallel extending thin walls (1a, 1b) which are interconnected by a structure of thin strip-shaped partitions (1c) situated between the walls. The longitudinal axes of all partitions extend parallel to each other and give the panel an anisotropic bending stiffness. The material of the walls and the partitions of the panel has an internal damping which is at least 2.5% of the critical damping of the relevant material, used in the panel.

Abstract: Panel-shaped loudspeaker comprising a panel (1) and an exciter coupled to the panel. The panel is provided with two parallel extending thin walls (1a, 1b) which are interconnected by means of a structure of thin strip-shaped partitions (1c) situated between the walls. The longitudinal axes of all partitions extend parallel to each other and give the panel an anisotropic bending stiffness. The material of the walls and the partitions, used in the panel, has an internal damping which is at least 2.5% of the critical damping of the relevant material, used in the panel.

Abstract: A passive radiator comprising a frame (1) and a radiator body (3) which is connected to the frame and which is movable relative to the frame along a translation axis (T). The radiator is suitable for the displacement of comparatively large air volumes. The radiator body comprises a central mass element (3a) and at least one mass element (3b, 3c, 3d) which is concentrically arranged with respect to the central mass element. The radiator further comprises connection units (5a, 5b, 5c, 5d) for the movable interconnection of each pair of adjoining mass elements and for the movable fastening of one of the mass elements to the frame.

Abstract: A passive radiator comprising a frame (1) and a radiator body (3) which is connected to the frame and which is movable relative to the frame along a translation axis (T). The radiator is suitable for the displacement of comparatively large air volumes. The radiator body comprises a central mass element (3a) and at least one mass element (3b, 3c, 3d) which is concentrically arranged with respect to the central mass element. The radiator further comprises connection units (5a, 5b, 5c, 5d) for the movable interconnection of each pair of adjoining mass elements and for the movable fastening of one of the mass elements to the frame.

Abstract: A device including two bodies (3, 5) which are disposed coaxially with respect to a translation axis (1), and including a comparatively compact suspension via which at least one of the bodies is movable with respect to the other body along the translation axis. The suspension, which allows comparatively large and accurately defined axial excursions of the one body with respect to the other body, includes a set of at least three blade spring elements (7) which are positioned around the translation axis. These blade spring elements each include two blade springs (7a, 7b) which are inclined with respect to a plane (XY) oriented perpendicularly to the translation axis, the blade springs of each blade spring element each having two peripheral portions (7a1, 7a2; 7b1, 7b2) which each extend parallel to the plane which is oriented perpendicularly to the translation axis.

Abstract: A loudspeaker system is physically integrated with a monitor. The monitor has a CRT. The loudspeaker system comprises an electro-acoustic transducer, a passive radiator and a tube mounted in between. The tube has a circular cross-section. The tube has an axis that is in parallel with a plane of the CRT's shadow mask.

Abstract: A passive radiator comprising a chassis, a mass element suspended within the chassis, and a suspension means for flexibly suspending the mass element from the chassis. In order to obtain a large amplitude of the mass element, a sub-chassis extends between the chassis and the mass element, first flexible connecting elements connecting the mass element to the sub-chassis, and second flexible connecting elements connecting the sub-chassis to the chassis.

Abstract: A sound-reproducing apparatus comprises an acoustic horn which terminates in an opening in the wall of the apparatus. An obstacle is arranged in the acoustic duct of the horn, which provides a better frequency response.