Abstract: The present invention relates to a loudspeaker device, comprising first and second closely located and individually acoustically isolated loudspeaker elements. The first and second elements are arranged to receive a first signal and a second signal, respectively, at least part of said first signal being in anti-phase relative to said second signal. The device further includes third and fourth loudspeaker elements, being located in close proximity to said first and second loudspeaker elements, respectively.

Abstract: The present invention relates to a method and a device for processing and reproducing an audio stereo signal. The method produces a left output signal for transmission to a left loudspeaker in a loudspeaker pair, which is, or is equivalent to, the sum of the mid input signal (M) and the side input signal (S), the method further produces a right output signal for transmission to a right loudspeaker in said pair, which is, or is equivalent to, the sum of the mid input signal (M) and the side signal (S) phase shifted 180° . The method further being characterized in that at least part of the side input signal (S) or the mid input signal (M) is phase shifted approximately 45°-135° relative to the other signal prior to or at the production of the left and right output signals. The invention further relates to such an audio stereo signal reproduction system.

Abstract: The present invention relates to a loudspeaker device, comprising first and second closely located and individually acoustically isolated loudspeaker elements. The first and second elements are arranged to receive a first signal and a second signal, respectively, at least part of said first signal being in anti-phase relative to said second signal. The device further includes third and fourth loudspeaker elements, being located in close proximity to said first and second loudspeaker elements, respectively.

Abstract: The present invention relates to methods and devices for processing one or the other of two types of common input audio stereo signals so that the output signals will reproduce normally wide stereo sound from an audio stereo reproduction system comprising a pair of identical loudspeakers positioned adjacent or close to each other. Thus, the invention relates partly to a method and a device for producing that specific pair of left and right output signals from one kind (M+S) of input signals, and partly to a method and a device for producing a similar type of left and right output signals from another kind (L+R) of input signals. Finally, the invention relates to an audio stereo signal reproduction system comprising a pair of identical louspeakers positioned adjacent or close to each other and intended for reproduction of normally wide stereo sound from one (M+S) of said kinds of input signals.

Abstract: A method of processing and reproducing an input audio stereo signal in an audio signal processing system comprises the steps of (1) splitting a side signal into a first and a second intermediate signal, where the first intermediate signal is equal to the side signal and the second intermediate signal is equal to the first intermediate signal phase shifted 180°, (2) attenuating the mid signal by a factor a which compensates for imperfections in the balance between the mid and side signals appearing in the audio reproduction stage, (3) adding the attenuated mid signal to both of the first and second intermediate signals, so as to form the output audio stereo signal, and (4) directing the output stereo signal to an audio stereo signal reproduction system, comprising a pair of loudspeaker units located in close proximity to each other.