Abstract: Apparatus for reproducing sound including at least three loudspeakers (5, 6, 7) mounted in a substantially sealed enclosure. The three loudspeakers may be mounted to a wall of the enclosure so that they are all directed away from, and evenly spaced around, a common point. Two speakers may be driven with the respective out of phase signals comprising the difference between two stereo channels and another speaker with the sum of those channels.

Abstract: Apparatus for reproduction of stereo sound from a two channel signal, having one or more first transducers (3a, 3b) for reproducing a signal comprising one of or the sum of the two channels, and one or more second transducers (5) for reproducing a signal comprising the difference between the two channels. The apparatus is arranged such that the signal generated by the one or more first transducers (3a, 3b) is transmitted from an output plane in a direction substantially orthogonal to the output plane. The apparatus also has a duct (6) associated with the one or more second transducers (5) and is arranged to conduct the signal generated by the one or more second transducers (5) such that it is transmitted along a direction substantially parallel to the output plane from a point spaced from the plane in the direction in which the signal generated by the one or more first transducers (3a, 3b) is transmitted.

Abstract: Apparatus for reproducing stereo sound having a housing (1, 25) defining an at least partially enclosed space. A first transducer (7) or pair of transducers (28, 29) is provided and arranged to reproduce one, both or the sum of two audio signals. A pair of transducers (10, 32) is also provided and arranged to reproduce a signal comprising the difference of the two audio signals. As the transducers communicate with the at least partially enclosed space, and the transducers arranged to reproduce the difference between the two audio signals are each arranged to direct their output primarily in a direction generally at right angles to the direction in which the first transducer or pair of transducers primarily direct their output. The apparatus may be arranged to be placed on or adjacent a generally flat surface, and the transducers arranged to reproduce the difference of the two audio signals may be arranged to direct their output towards the flat surface.

Abstract: A method of using an audio device (2) for improving a user's (1) listening experience. The audio device has a transducer (12) for producing output sound and the method comprises the steps of driving the transducer to produce an output sound and placing the audio device against the body of the user so that the user experiences a physical response to the sound while simultaneously listening to the audio device. The audio device may be arranged to produce a resonance in a part of the user's body. Preferably the audio device is positioned on the user's chest to produce a resonance in the chest cavity of the user's body. The audio device may comprise a sum and difference speaker system.

Abstract: Apparatus for reproducing sound including at least three loudspeakers (5, 6,7) mounted in a substantially sealed enclosure. The three loudspeakers may be mounted to a wall of the enclosure so that they are all directed away from, and evenly spaced around, a common point. Two speakers may be driven with the respective out of phase signals comprising the difference between two stereo channels and another speaker with the sum of those channels.

Abstract: A method of using an audio device (2) for improving a user's (1) listening experience. The audio device has a transducer (12) for producing output sound and the method comprises the steps of driving the transducer to produce an output sound and placing the audio device against the body of the user so that the user experiences a physical response to the sound while simultaneously listening to the audio device. The audio device may be arranged to produce a resonance in a part of the user's body. Preferably the audio device is positioned on the user's chest to produce a resonance in the chest cavity of the user's body. The audio device may comprise a sum and difference speaker system.

Abstract: Apparatus for reproducing stereo sound having a housing (1, 25) defining an at least partially enclosed space. A first transducer (7) or pair of transducers (28, 29) is provided and arranged to reproduce one, both or the sum of two audio signals. A pair of transducers (10, 32) is also provided and arranged to reproduce a signal comprising the difference of the two audio signals. As the transducers communicate with the at least partially enclosed space, and the transducers arranged to reproduce the difference between the two audio signals are each arranged to direct their output primarily in a direction generally at right angles to the direction in which the first transducer or pair of transducers primarily direct their output. The apparatus may be arranged to be placed on or adjacent a generally flat surface, and the transducers arranged to reproduce the difference of the two audio signals may be arranged to direct their output towards the flat surface.

Abstract: An apparatus and method for reproducing stereo sound. A transducer (14) is provided for reproducing two audio signals which are substantially out of phase with each other. Means, such as duct (11), are associated with the transducer to conduct at least one of the audio signals to a location such that the two substantially out of phase signals are transmitted from respective spaced apart locations. The duct (11) may lead to ports (4). These may be elongate and arranged to transmit sound across a flat surface. A second transducer (8) may be provided for transmitting a second audio signal. A conventional two channel stereo audio signal may be reproduced by the sum and difference system.