Patent ID: 8620010

Claim:
Loudspeaker device, comprising first and second loudspeaker elements, which are located in close proximity to each other, wherein said first and second loudspeaker elements are arranged to radiate sound in a first direction of propagation, wherein said first and second loudspeaker elements are acoustically isolated and arranged to receive a first signal and a second signal having a first frequency range, respectively, at least part of said first signal being in anti-phase relative to said second signal, wherein said device further includes third and fourth loudspeaker elements, arranged to propagate sound in said first direction, said third loudspeaker element being located in close proximity to said first loudspeaker element and arranged to receive at least part of said first signal, the center of said third loudspeaker element being located such that a first axis intersecting the center of said first loudspeaker element and the center of said third loudspeaker element is inclined an angle Ï† relative to a horizontal plane, Ï† being in the range 0Â°-Â±30Â°, said fourth loudspeaker element being located in close proximity to said second loudspeaker element and arranged to receive at least part of said second signal, the center of said fourth loudspeaker element being located such that a second axis intersecting the center of said second loudspeaker element and the center of said fourth loudspeaker element is inclined at an angle Ï† relative to a horizontal plane, Ï† being 0Â°-Â±30Â°, characterized in said first and second signals to said third and fourth loudspeaker elements, respectively, being low-pass filtered, the cut-off frequency of said low-pass filters being less than or equal to 2.5 kHz, the signals being received by said third and fourth loudspeaker elements having substantially the same amplitude as the signals being received by said first and second loudspeaker elements in said low-pass filtered portion of said first frequency range.