Dynamic Parametric Equalizer Gain Adjustment via Lookup Table
Solution Overview
Problem
Conventional parametric equalizers face challenges in dynamically adjusting their gain to prevent signal clipping, requiring complex real-time calculation of filter coefficients, which increases hardware complexity and manufacturing costs.
Innovation Solution
A method and system that dynamically adjust the gain of a parametric equalizer by using a first signal processing unit with a preset transfer function H1 and a second signal processing unit with a transfer function H2, where the gain is adjusted based on the level of the input signal without real-time coefficient calculation, using equations H1=[H(z)−1]/(G−1), H2=G−1 for 0<Gin<1/G, H2=1/Gin−1 for 1/G≤Gin≤1, and H2=0 for 1<Gin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If real-time calculation of filter coefficients is performed to dynamically adjust gain, then signal clipping is prevented, but hardware complexity and manufacturing costs increase
Solution Approach 1:
The patent pre-calculates and stores filter coefficients for multiple gain values in a lookup table before operation. During real-time processing, the system simply retrieves the appropriate pre-calculated coefficients based on the current signal level, avoiding complex real-time calculations while maintaining dynamic gain adjustment capability and preventing signal clipping.
2Reliability
If real-time calculation of filter coefficients is performed to dynamically adjust gain, then signal clipping is prevented, but manufacturing costs rise
Solution Approach 1:
The patent pre-calculates and stores filter coefficients for multiple gain values in a lookup table before operation. During real-time processing, the system simply retrieves the appropriate pre-calculated coefficients based on the current signal level, avoiding complex real-time calculations while maintaining dynamic gain adjustment capability and preventing signal clipping.
3Device complexity
If preset gain is used without dynamic adjustment, then hardware complexity is reduced, but signal clipping occurs when input level is high
Solution Approach 1:
The patent implements dynamic gain adjustment by detecting the input signal level and selectively applying different pre-calculated filter coefficients from a lookup table. The system transitions from a static preset gain approach to a dynamic approach where the filter characteristics automatically adapt to the input signal level, preventing clipping while maintaining signal quality without requiring complex real-time coefficient calculation hardware.
Data Source
AI summary
The present invention relates to a method for dynamically adjusting a gain of parametric equalizer according to an input signal, a dynamic parametric equalizer employing the same and a dynamic parametric equalizer system employing the same wherein a gain of parametric equalizer is dynamically adjusted according to a level of an input digital audio signal to prevent distortion of output signal.