Dynamic Leveling Equalizer for Flat Response at Low Volume

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Solution Overview

Problem

As the volume of playback devices decreases, human hearing becomes less sensitive to low frequency bands below 1 kHz and high frequency bands above 7 kHz, leading to reduced listening quality due to inability to distinguish sound components at low volumes.

Innovation Solution

A leveling equalizer is designed with a graphic equalizer circuit, multiplication circuits, an addition circuit, and a gain control circuit to dynamically adjust gain values, processing input signals into separate frequency bands and combining adjusted outputs to maintain a flat frequency response across all volumes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the volume of playback device is decreased, then power consumption is reduced, but hearing sensitivity to low frequency band and high frequency band deteriorates

Engineering Contradiction:

Improvepower consumptionVSAvoidhearing sensitivity

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic gain adjustment where the equalizer circuit changes frequency response characteristics based on detected signal characteristics. The gain values for different frequency bands are dynamically modified according to the energy distribution in the input signal, allowing the system to adapt to different listening conditions and maintain hearing sensitivity even at lower volumes.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the gain parameters of different frequency bands based on the detected signal characteristics. When low frequency or high frequency components are weak in the input signal, the equalizer increases the gain for those bands to compensate, ensuring balanced frequency response and maintaining hearing sensitivity across all volume levels.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the volume of playback device is decreased, then listening environment becomes quieter, but frequency response flatness deteriorates

Engineering Contradiction:

Improvepower consumptionVSAvoidfrequency response flatness

Core Design Contradiction:

Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The patent employs feedback mechanisms where the equalizer circuit continuously monitors the input signal characteristics and adjusts the frequency response accordingly. The detection circuit analyzes the energy distribution across frequency bands and feeds this information back to the equalizer, which then modifies its gain settings to maintain a flat frequency response regardless of the overall signal level.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The equalizer dynamically adjusts its frequency response characteristics based on real-time signal analysis. When the input signal lacks certain frequency components or when played at low volumes, the system automatically compensates by adjusting gain values, ensuring the frequency response remains flat and balanced across all operating conditions.

Inventive Principle:

Principle #15Dynamics

3Reliability

If gain adjustment is applied to compensate hearing sensitivity, then frequency response flatness is improved, but device complexity increases

Engineering Contradiction:

Improvehearing sensitivityVSAvoidequalizer circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the frequency spectrum into multiple bands and applies independent gain control to each band. The equalizer circuit is segmented into several parallel processing channels, each handling a specific frequency range with its own gain adjustment mechanism. This segmentation allows for targeted compensation of frequency deficiencies while keeping each individual processing channel relatively simple.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The equalizer circuit is designed to perform multiple functions: it detects signal characteristics, analyzes frequency distribution, adjusts gain values, and maintains frequency response flatness all within a single integrated system. This multi-functionality reduces the need for separate dedicated circuits for each task, thereby managing overall device complexity while achieving comprehensive hearing sensitivity compensation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11757420B2Method for dynamically adjusting adjustable gain value to equalize input signal to generate equalizer output signal and associated leveling equalizer

Publication Date: 2023.09.12 ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC

AI summary

A leveling equalizer includes a graphic equalizer circuit, a first multiplication circuit, a second multiplication circuit, an addition circuit, and a gain control circuit. The graphic equalizer circuit processes a first input signal and output a first output signal and a second output signal. The first multiplication circuit multiplies the first output signal and one of an adjustable gain value and a fixed gain value to generate a first adjusted output signal. The second multiplication circuit multiplies the second output signal and another of the adjustable gain value and the fixed gain value to generate a second adjusted output signal. The addition circuit combines the first adjusted output signal and the second adjusted output signal to generate an equalizer output signal. The gain control circuit dynamically adjusts the adjustable gain value according to the equalizer output signal.