Directional Audio Transducer Array Harmonic Filtering
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Solution Overview
Problem
Conventional transducer arrays face challenges in achieving directional control of low-frequency sound reproduction due to large wavelengths, leading to the need for large arrays, increased costs, and compromised sound quality, especially in reproducing a wide frequency range with a single type of transducer.
Innovation Solution
The method involves processing audio signals by filtering harmonics in a directionally controllable frequency band to represent low-frequency content using higher frequency harmonics, allowing for directional sound reproduction with a compact transducer array, utilizing the phenomenon of virtual pitch to enhance perceived sound quality and reduce array size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a large transducer array is used to achieve directional control at low frequencies, then directional control is improved, but device size and cost increase
Solution Approach 1:
The patent applies parameter changes by processing low-frequency bass signals through non-linear processing to generate harmonics in higher frequency ranges. This transforms the frequency parameters of the signal, allowing the transducer array to reproduce bass content through harmonics rather than directly reproducing low frequencies, thereby achieving directional control without requiring a large physical array size
Solution Approach 2:
The patent substitutes the mechanical approach of using a large physical transducer array for directional control with a signal processing approach. Instead of mechanically increasing array size to control low-frequency directionality, the system uses digital signal processing to generate harmonics that can be directionally controlled by a compact array
2Ease of manufacture
If a single type of loudspeaker driver is used to reduce cost, then manufacturing cost is reduced, but frequency range reproduction capability deteriorates
Solution Approach 1:
The patent makes a single type of loudspeaker driver perform multiple functions by using non-linear processing to generate harmonics. The same driver type reproduces both the fundamental bass frequencies and the generated harmonics, effectively extending the frequency range capability without requiring different driver types for different frequency ranges
Solution Approach 2:
The patent changes the frequency parameters of the input signal through non-linear processing, generating harmonics at integer multiples of the original frequency. This allows a single driver type to effectively reproduce a wider frequency range by synthesizing higher frequency content from lower frequency inputs
3Device complexity
If simple geometry arrays like line arrays are used, then device complexity is reduced, but directional control in multiple dimensions deteriorates
Solution Approach 1:
The patent substitutes the mechanical solution of complex multi-dimensional array geometries with a signal processing solution. By generating harmonics through non-linear processing, the system achieves improved directional control without requiring complex array geometries, maintaining simple configurations while enhancing performance
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
This approach enables effective directional control of sound across a wide frequency range with a single type of transducer, reducing the size and cost of the transducer array while maintaining high sound quality, allowing for targeted sound reproduction in specific directions.
Implementation Method 1
reproducing directional sound representing said input audio signal based on said plurality of generated driver signals using said transducer array
Implementation Method 2
processing said input audio signal by signal processing to generate a processed audio signal, wherein said processing comprises filtering harmonics in a directionally controllable frequency band
Data Source
AI summary
Disclosed is a method for directionally reproducing an input audio signal by a transducer array comprising a plurality of transducers, the method comprising receiving said input audio signal and processing by signal processing to generate a processed audio signal, the processing comprising filtering harmonics in a directionally controllable frequency band, each of said harmonics corresponding to a lower order harmonic in a bass frequency band, wherein said bass frequency band comprises frequencies below said directionally controllable frequency band, generating a plurality of driving signals for said plurality of transducers, wherein said plurality of driving signals are generated on the basis of said processed audio signal by application of directional control filters, and reproducing directional sound representing said input audio signal based on said plurality of generated driver signals using said transducer array. A transducer array system for directionally reproducing an input audio signal is further disclosed.