Frequency-Domain Gain Control for Loudspeaker Excursion Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio devices struggle to effectively control the dynamic range of loudspeakers to prevent damage while maintaining optimal audio performance, as current methods often result in audio artefacts and inadequate protection against excessive diaphragm displacement.
Innovation Solution
A gain function controller that determines a frequency-domain-gain-function for sub-band signals based on the power of a full-band signal and a predetermined compression curve, allowing for superior control of the dynamic range and preventing loudspeaker damage by limiting diaphragm displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing dynamic range control methods are used, then loudspeaker protection is provided, but audio artefacts are generated and audio performance deteriorates
Solution Approach 1:
The patent divides the audio signal into multiple frequency sub-bands and applies independent gain control to each sub-band. This segmentation allows selective attenuation of problematic frequency components while preserving other frequency ranges, thereby preventing audio artefacts while maintaining loudspeaker protection. The frequency-domain processing enables granular control over different spectral regions.
Solution Approach 2:
The patent applies different gain values to different frequency sub-bands based on local signal characteristics and loudspeaker excursion risks. Rather than uniform compression across all frequencies, the system tailors the dynamic range control to specific frequency regions, applying stronger compression only where necessary to prevent diaphragm displacement while maintaining audio quality in other bands.
2Reliability
If aggressive dynamic range compression is applied to prevent loudspeaker damage, then protection is improved, but audio reproduction quality deteriorates
Solution Approach 1:
By segmenting the audio spectrum into multiple sub-bands, the patent enables selective application of compression only to frequency ranges that pose a risk to loudspeaker diaphragm displacement. This frequency-selective approach preserves the natural dynamics and quality of audio content in safe frequency regions while providing protection only where physically necessary.
Solution Approach 2:
The patent dynamically adjusts gain parameters for each frequency sub-band based on real-time analysis of signal power and predicted loudspeaker excursion. The compression ratio and threshold parameters are adapted per frequency band, allowing aggressive compression for problematic frequencies while maintaining gentle or no compression for frequencies that do not threaten loudspeaker safety, thus preserving overall audio reproduction quality.
Data Source
AI summary
A gain function controller may be configured to: receive a first plurality of sub-band-signals; determine a frequency-domain-gain-function for a second plurality of sub-band-signals, based on: the first plurality of sub-band-signals; a power of a first full-band signal; and a predetermined compression curve; and apply the frequency-domain-gain-function to the second plurality of sub-band-signals to provide a frequency-domain-output-signal.