Steerable Speaker Array With Nested Drivers For Directional Control
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Solution Overview
Problem
Conventional speaker systems face challenges in providing optimal directivity and aesthetic design for voice applications in environments like offices and conferencing spaces, due to spatial and aesthetic limitations, as well as high computational complexity and cost, especially in achieving directional control across all frequencies.
Innovation Solution
A steerable speaker array with a concentric, nested configuration of drivers, where each driver is positioned at different radial distances from a central point, allowing for improved directivity and main-to-side lobe ratio over a prescribed steering angle range, combined with a beamforming system for enhanced audio features like acoustic echo cancellation and spatialized audio streams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a two-dimensional speaker array with multiple line arrays is used to provide directional control in all directions, then directivity control is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent applies nesting by arranging multiple line arrays within a single housing structure, where each line array consists of multiple transducers positioned at different depths. This nested configuration allows the system to achieve three-dimensional directional control without requiring a large two-dimensional array, thereby reducing the total number of drivers while maintaining adaptability for steering sound beams in multiple directions.
Solution Approach 2:
The patent transitions from two-dimensional array arrangements to a three-dimensional configuration by positioning transducers at different depths within the housing. This dimensional change enables directional control in elevation and azimuth using fewer drivers, as the third dimension (depth) provides additional spatial degrees of freedom for beamforming without increasing the footprint area.
2Reliability
If larger cone size speakers are used to provide high fidelity full-range response, then sound quality is improved, but spatial requirements and visual impact increase
Solution Approach 1:
The patent uses nesting to place multiple transducers of varying sizes at different depths within a compact housing. This allows the system to incorporate larger transducers for low-frequency reproduction without increasing the external footprint, as the larger elements are positioned internally rather than externally. The nested arrangement maintains high fidelity full-range response while minimizing visual impact and spatial requirements.
Solution Approach 2:
The patent exploits the depth dimension to accommodate larger transducer elements without increasing the horizontal or vertical footprint. By arranging transducers at different depths within the housing, the system can include larger cone size speakers for high fidelity sound reproduction while keeping the overall speaker array compact and aesthetically suitable for office and conferencing environments.
3Adaptability or versatility
If transducers are positioned closer together to improve directional control at higher frequencies, then directivity is improved, but side lobe growth increases
Solution Approach 1:
The patent applies local quality by assigning different spacing configurations to different groups of transducers based on their positions and functions. Rather than using uniform spacing throughout the array, the system optimizes spacing locally for each transducer group to achieve appropriate directional control at various frequencies while minimizing side lobe generation in specific directions. This localized optimization allows closer spacing where beneficial while maintaining larger spacing where it prevents side lobe growth.
Solution Approach 2:
The patent implements dynamic spacing adjustments through electronic beamforming control, where the effective spacing between transducers can be varied programmatically depending on the desired beam direction and frequency. This dynamic approach allows the system to optimize directional control by adjusting phase and amplitude relationships between transducers, effectively changing the acoustic spacing without physical movement, thereby controlling side lobe growth adaptively across different operating conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a more consistent and improved directivity index with reduced side lobe growth, allowing for wider beam steering and better frequency response across the voice range, while minimizing the number of drivers required, thus reducing system size and weight, and enhancing audio quality and intelligibility in voice applications.
Implementation Method 1
Line arrays provide the ability to steer the sound beams output by the individual speakers towards a given listener using appropriate beamforming techniques
Implementation Method 2
the transducers of an upright column speaker can provide a controlled degree of directionality in the vertical plane
Data Source
AI summary
Embodiments include an audio system comprising a speaker array comprising a plurality of drivers arranged in a first planar configuration; a microphone array comprising a plurality of transducers arranged in a second planar configuration; and a beamformer communicatively coupled to the speaker array and the microphone array, the beamformer configured to: generate an individual speaker output signal for each of the drivers in the speaker array based on one or more input audio signals received from an audio source, and generate a microphone output signal for the microphone array based on one or more microphone signals captured by one or more of the transducers. Embodiments also include a method performed by one or more processors coupled to a microphone array having a plurality of transducers and a speaker array having a plurality of drivers.