Dynamic Range Compensation for Audio Distortion Control
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Solution Overview
Problem
Audio systems face challenges in preventing distortion due to the inherent non-linearities and mechanical properties, leading to hard and soft distortions, which are difficult to address through coordinated design of components like power amplifiers, loudspeakers, and enclosures.
Innovation Solution
A system utilizing a total harmonic distortion (THD) modeling system applies a chirp signal to identify distortion frequency bands and uses dynamic range compensation by applying a ramping signal to limit the input signal amplitude at these bands, employing dynamic equalizers and multiband dynamic range controllers to prevent distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If coordinated design of components (amplifiers, loudspeakers, enclosures) is implemented to prevent distortion, then distortion reduction is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces mechanical/coordinated design approaches with signal processing. Instead of designing amplifiers, loudspeakers, and enclosures to work together mechanically to prevent distortion, the system uses digital signal processing to identify distortion frequency bands and apply dynamic range compensation to limit signal amplitude, substituting physical coordination with electronic control.
Solution Approach 2:
The patent changes the parameter approach by dynamically adjusting signal amplitude parameters based on measured distortion characteristics. The system measures total harmonic distortion across frequency bands and modifies signal parameters (amplitude limiting) in real-time to maintain distortion below thresholds, rather than relying on fixed mechanical design parameters.
2Reliability
If dynamic range compensation is applied to limit signal amplitude at distortion frequency bands, then distortion levels are reduced, but signal processing complexity increases
Solution Approach 1:
The patent segments the audio signal into multiple frequency bands using filters. Instead of processing the entire signal uniformly, the system divides it into distinct frequency ranges, applies distortion measurement and amplitude limiting independently to each band, then recombines them. This segmentation allows targeted distortion control without processing the entire signal space.
Solution Approach 2:
The patent implements feedback by measuring the actual distortion output of the audio system, comparing it against predetermined thresholds, and using this information to adjust signal amplitude in real-time. The distortion measurement unit continuously monitors output, and the dynamic range compensation unit adjusts input signal parameters based on this feedback to maintain distortion control.
3Reliability
If multiband dynamic range controllers and equalizers are used to manage distortion thresholds, then distortion-free sound quality is improved, but system complexity and processing time increase
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing distortion thresholds for different frequency bands and signal conditions. The system has predetermined distortion thresholds that are established in advance, allowing rapid comparison during real-time signal processing without performing complex calculations at the moment of distortion detection.
Data Source
AI summary
A system for controlling distortion comprising a total harmonic distortion (THD) modeling system configured to apply a chirp signal to a system and to identify one or more frequency bands at which distortion is present, and to apply a ramping signal to identify for each of the one or more frequency bands an input signal level at which distortion is initiated. A signal processing system configured to receive an input signal, to determine whether frequency components are present in the input signal that are associated with the one or more frequency bands at which distortion is present, and to limit the amplitude of the input signal at the one or more frequency bands, such as by applying dynamic range compensation.