Abstract: A loudspeaker arrangement (800) having first and second loudspeakers mechanically coupled to each other. Either a first side of a first sound radiating surface faces a first side of a second sound radiating surface, and the first side of the first sound radiating surface and the first side of the second sound radiating surface both face a first cavity having a first opening facing towards an internal air volume, or a second side of the first sound radiating surface faces a second side of the second sound radiating surface, the first side of the first sound radiating surface faces a second cavity having a second opening facing towards the internal air volume, and the first side of the second sound radiating surface faces a third cavity separate and distinct from the second cavity, the third cavity has a third opening facing towards the internal air volume.

Abstract: In at least one embodiment, a loudspeaker assembly is provided. The loudspeaker assembly includes a supporting ring, a flexible surround, a voice coil, a dome, and a bearing ring. The flexible surround includes a first end being attached to the supporting ring and a second end positioned opposite to the first end. The voice coil is positioned about the flexible surround. The dome is positioned about the voice coil and the second end of the flexible surround. The bearing ring is attached to the voice coil and separates the flexible surround from the dome.

Abstract: A method for generating a signal having a defined bandwidth and a desired crest factor is disclosed. The signal is composed of a number of individual sinusoidal signals, each having an amplitude and a frequency. The method includes determining an exponent to be used in a specific exponential function and corresponding to the desired crest factor, the exponent being determined based on an a priori known relationship between crest factor and exponent; calculating a phase value for each sinusoidal signal using the specific exponential function and the previously determined exponent; and superposing the sinusoidal signals to obtain the signal having the desired crest factor, whereby the phases of the individual signals are maintained.

Abstract: The present invention is directed to systems and methods of distinguishing acoustic noise from valid plate contacts in vibration sensitive devices such as vibration sensing touch panels. The energy content of the detected vibration spectrum can be analyzed for features characteristic of noise, for example a higher relative contribution from high frequencies due in part to preferential coupling of above coincidence frequencies over below coincidence frequencies.

Abstract: A loudspeaker comprising a panel adapted to support bending waves and an exciter for exciting said bending waves employs an exciter having an effective size with which it acts on said panel, the effective size varying in dependence on the frequency with which the exciter acts on the panel. Exciters suitable for use in such a loudspeaker are also disclosed.

Abstract: A method of and apparatus for producing acoustic output employs a bending wave member to which a number of exciters are coupled over at least part of the area. The exciters are individually addressable to generate impulses in response to digital input that has been suitably shaped and delayed, the impulses being integrated in the panel so that a form of synchronous summation takes place by bending action making use of the dispersive properties of the device. The resulting acoustic output has a reinforced fundamental frequency and reduced harmonics.