Second-Order Acoustic Differential Loudspeaker Array Directivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Differential loudspeaker arrays face limitations in directivity as frequency decreases, with first-order arrays limited to about 6 dB, and existing technologies struggle to maintain directivity at low frequencies, necessitating an improved approach for sound reproduction systems.
Innovation Solution
A calculation unit for a sound reproduction system with at least three transducers, including input means and a processor to generate second or higher-order acoustic differentials, allowing for better directivity performance across various frequency ranges by using different transducer configurations and passband characteristics to control the loudspeakers effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If first-order differential arrays are used, then directivity can be achieved, but the directivity level is limited to about 6 dB and does not improve at lower frequencies
Solution Approach 1:
The patent changes the order parameter of the acoustic differential from first-order to second-order or higher. This parameter change enables the system to achieve greater than 6 dB directivity and maintains directivity performance at lower frequencies where first-order arrays fail. The second-order differential creates a more pronounced null in the opposite direction, providing improved directivity control across the frequency spectrum.
2Measurement precision
If higher-order gradient loudspeakers are used, then directivity may be improved, but the system becomes less efficient and requires more transducers and signal processing
Solution Approach 1:
The patent makes the transducer array universally applicable across multiple frequency ranges by implementing second-order or higher differentials. The same array configuration that provides improved directivity at mid frequencies also maintains effectiveness at lower frequencies, eliminating the need for additional specialized transducers for different frequency bands. This multi-functional approach resolves the contradiction by achieving higher directivity without proportionally increasing transducer count.
3Measurement precision
If differential loudspeaker arrays are used, then directivity can be achieved, but the directivity level decreases to zero as frequency goes to zero
Solution Approach 1:
The patent changes the differential order parameter from first-order to second-order or higher, which fundamentally alters the frequency response characteristics. Second-order differentials maintain a non-zero directivity level as frequency approaches zero, unlike first-order differentials whose directivity vanishes at low frequencies. This parameter change enables sustained directivity performance across the entire frequency spectrum including bass frequencies.
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 improved sound reproduction by generating second or higher-order acoustic differentials, enhancing directivity performance in specific frequency ranges while avoiding limitations of lower-order differentials in other ranges, allowing for more effective sound reproduction across a broader frequency spectrum.
Implementation Method 1
a calculation unit for a sound reproduction system including an array having at least three transducers... calculate at least three individual audio signals such that a second or higher order acoustic differential is reproduced using the array
Implementation Method 2
Directive microphones are usually implemented by means of measuring a sound pressure gradient... First order gradient has a figure-of-eight directivity pattern
Data Source
AI summary
A calculation unit for a sound reproduction system includes an input unit, a processor and at least three outputs for controlling at least three transducers of an array. The input unit has the purpose to receive an audio stream to be reproduced using the array, wherein the audio stream has a frequency range. The processor is configured to calculate three individual audio signals to be output using the at least three outputs, such that a first acoustic differential having a second or higher order is generated using the array.