Abstract: A tweeter with a light, thin sandwich plate which can be excited into multiple reflected bending waves, and a driver which makes a vibrating contact and excites the sandwich plate, where the driver is designed for higher sound frequencies and the sandwich plate for propagating bending waves with low damping. The sandwich plate is freely carried with low damping by holding elements, where the latter are designed to be low damping at higher sound frequencies.

Abstract: The invention relates to the embodiment of so-called panel loudspeakers working according to the bending wave principle. Said panels are generally formed by a panel (11), at least one driver (12) and a frame (13), the panel (11) being connected to the frame (13). In order to achieve appropriate bending wave induction in the panel (11), very complicated assessments must be made in order to determine the corresponding positioning areas (15) in which the driver (12) excites the panel (11) or is connected to the latter. Furthermore, the size of the panels (11) can change considerably depending on the application so that assessments must only be made repeatedly in the case of panels that can be easily modified. The invention aims at providing general positioning areas (15) for the driver (12) in or on the panels (11) so that no further assessments need to be carried out regarding the positioning area (15).

Abstract: The invention relates to a system with multi-mode radiator panels used to reproduce sound. The multi-mode radiator panels include at least one driver, a core layer and two cover layers connected to the core layer. The panels are typically mounted in a frame with attachments providing a connection between the frame and the unit formed of the core layer and the cover layers. To protect the system against overload and damage, the entire driver electronics is housed in a hermetically sealed air space located between the frame, the core layer and the attachments. The driver electronics includes a power amplifier powered by low-voltage power supply. The voltage supply may be buffered by a battery to keep the average power supplied to the electronics small, while still being able to reproduce infrequently occurring peak power events.

Abstract: The invention concerns the embodiment of panel loudspeakers working according to the bending wave principle. Said loudspeakers are generally formed by at least one acoustic panel (11) and at least one driver (12), the driver (12) being connected to the acoustic panel (11). When such acoustic panels (11) are used for reproducing low frequency audio signals, the acoustic panel (11) must be arranged in sufficiently large sound walls in order to exclude the occurrence of an acoustic short circuit between the front part and the back part of the panel. Apart from being costly, only one side of the sound walls is actively used for sound generation as a result of the separation of both acoustic panels (11). Hence, the invention aims at providing a panel loudspeaker (10) that does not require any additional sound walls in order to exclude the occurrence of an acoustic short circuit while at the same time enabling full utilization of the surface of the acoustic panel (11) for sound generation.

Abstract: The invention proposes a contact connection for sound reproduction devices according to the flexural wave principle. Since the drive systems 21 of such installations require high current intensities and such current intensities could only be properly transmitted by massive contact connections which however hinder the flexural wave propagation, the object of the invention is to propose a contact connection which eliminates the problems of the state of the art, and which is also very easy to implement. To that end it is proposed that at least one of the two cover layers 12 and/or the core layer 11 contain conductive areas 17 which are connected to the lines 32 of a sound signal source. It is particularly advantageous if the conductive areas 17 can be manufactured together with the components that are also used to manufacture the core layer 11.

Abstract: The invention relates to the embodiment of panel loudspeakers 10 working according to the bending wave principle. Such loudspeakers 10 generally consist of an acoustic panel 11 and drivers 12, whereby the drivers 12 are connected to the acoustic panel 11. For the formation of bending waves in the acoustic panel 11, it is essentially important that the drivers 12 do not unnecessarily rigidize the acoustic panel 11. This has led to the arrangement of the drivers 12 at a distance from the acoustic panel 11 in a separate frame. In view of the complexity of such an arrangement, the invention aims at providing a connection between the drivers 12 and the acoustic panel 11 that can be supported directly on the acoustic panel 11 and which does not impede the propagation of the bending waves. This is achieved by connecting the drivers to the acoustic panel only at very few points 24 or by providing elastic member 25 in the fixing area of the drivers. A combination of both embodiments is also described.

Abstract: A projection screen, having a projection surface formed of at least two segments, of which at least two segments are sound radiating segments capable of radiating sound waves from the projection surface and designed to reproduce different frequency ranges.

Abstract: The invention concerns the embodiment of drivers for panel loudspeakers. Panel loudspeakers working according to the principle of bending waves are already known in prior art. Said loudspeakers generally consist of an acoustic panel (11) and at least one driver (12). As a general rule, the driver (12) is arranged on an auxiliary frame at a distance from the acoustic panel (11). Said embodiment makes it possible to use conventional drivers (12) that can also be utilized in cone loudspeakers. A series of problem arise when the drivers (12) are to be integrated on or into the acoustic panel (11) itself. Said embodiment requires inter alia that the different components of the driver (12) be directly mounted on the acoustic panel (12). Hence, the invention aims at providing a driver for panel loudspeakers that can be connected with little complications to the acoustic panel (11) as a pre-fabricated component.

Abstract: A tweeter with a light, thin sandwich plate which can be excited into multiple reflected bending waves, and a driver which makes a vibrating contact and excites the sandwich plate, where the driver is designed for higher sound frequencies and the sandwich plate for propagating bending waves with low damping. The sandwich plate is freely carried with low damping by holding elements, where the latter are designed to be low damping at higher sound frequencies.

Abstract: The invention presents a sound reproduction device which operates in accordance with the flexural wave principle. Such devices have in common that a panel 10 is provided in which flexural waves are produced by a drive arrangement 16. The drive arrangements 16 in the state of the art are connected to one of the surfaces of the panel 10 and are held by a support structure which functions as a countersupport. Such support structures either hinder the propagation of the flexural waves along the surface of the panel 10 and/or lead to an increase in the constructed depth of such a sound reproduction device. To avoid these disadvantages of the state of the art, the drive system 16 is located in a cutout 15 of the panel 10.

Abstract: The invention relates to acoustic walls for large public events. Traditionally, sound is reproduced by using a plurality of large and heavy loudspeaker boxes which requires a complicated and expensive support system. The present invention provides a segmented acoustic wall which has an essentially flat shape and is also extremely lightweight. Several of these segments can be integrated to form an acoustic wall by coupling the different segments with one another, whereby the entire surface area of the acoustic wall can be used to radiate sound without requiring additional sound sources in the audience space. The various segments can be optimized for certain frequency ranges by tuning the surface area and depth of the respective segments to the respective transmitted frequencies. Several acoustic walls can be placed side-by-side to flexibly conform to different requirements in the audience space.