Stereo Sound Apparatus Using Perpendicular Difference Transducers
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Solution Overview
Problem
Conventional two-channel stereo sound reproduction systems face challenges in recreating the stereo effect when loudspeakers are close together or when listeners are not positioned optimally, leading to a poor stereo experience, and existing sum and difference systems have not been widely adopted due to practical difficulties.
Innovation Solution
The apparatus employs a housing with a single transducer for the sum signal and two transducers for the difference signal, oriented at right angles and directed towards a flat surface to enhance the stereo effect, combining advantages of conventional two-speaker systems and sum and difference systems, with the transducers sharing a common acoustic enclosure to simplify construction and increase perceived depth and width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If loudspeakers are spaced close together to fit in compact equipment, then device size is reduced, but stereo effect quality deteriorates
Solution Approach 1:
The invention divides the stereo reproduction function into two separate signal processing paths: sum signal path and difference signal path. The sum signal (L+R) is reproduced by a first transducer while the difference signal (L-R) is reproduced by second transducers positioned at right angles. This segmentation allows compact physical arrangement while maintaining stereo effect quality through directional sound field manipulation.
Solution Approach 2:
The invention introduces a spatial dimension solution by positioning difference signal transducers perpendicular to the main listening axis. Instead of increasing separation distance along the horizontal axis, the system utilizes the vertical/dimensional space by directing difference signals at right angles, creating a three-dimensional sound field that preserves stereo effect in compact form factor.
2Manufacturing precision
If loudspeakers are spaced far apart to improve stereo effect, then stereo effect quality is improved, but device size increases
Solution Approach 1:
The system resolves the size-quality contradiction by transitioning from one-dimensional horizontal separation to three-dimensional spatial arrangement. Difference signal transducers are positioned and oriented perpendicular to the main listening direction, creating vertical/dimensional separation that achieves stereo effect without increasing horizontal device footprint.
Solution Approach 2:
The invention changes the spatial orientation parameter of the transducers from conventional horizontal alignment to perpendicular alignment. By orienting difference signal transducers at right angles to the sum signal transducer, the system creates directional sound fields that achieve wide stereo effect in compact configuration.
3Manufacturing precision
If the sum and difference system is implemented with conventional speaker arrangements, then stereo effect should be improved, but practical difficulties arise resulting in poor sound quality
Solution Approach 1:
The invention segments the speaker system into functionally distinct groups: a first transducer for sum signal and second transducers for difference signals. This clear functional segmentation simplifies the implementation of the sum-and-difference system by assigning specific roles to each transducer group, avoiding the confusion and practical difficulties of conventional mixed arrangements.
Solution Approach 2:
The system changes the orientation parameter of difference signal transducers to be perpendicular to the sum signal transducer. This parameter change simplifies the acoustic field manipulation required for sum-and-difference decoding, making the system more practical to implement while achieving the theoretical stereo effect quality.
4Manufacturing precision
If difference signal transducers are oriented perpendicular to the listening direction, then stereo width and depth are enhanced, but transducer arrangement complexity increases
Solution Approach 1:
The invention segments transducers by signal type and orientation function. First transducers handle sum signals in the main listening direction while second transducers handle difference signals perpendicular to it. This segmentation of functional roles simplifies the overall arrangement complexity by creating clear spatial and functional zones within the device.
Data Source
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AI summary
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. All 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.