Nonlinear Loudspeaker Control for Bass Extension and Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional loudspeakers suffer from nonlinear audio distortion, which impairs sound quality and speech intelligibility, particularly in smaller-sized designs that trade size for portability, leading to increased audio distortion and reduced bass output.
Innovation Solution
A nonlinear control system for loudspeaker drivers that uses a controller to determine target displacements and sound pressures based on physical models, generating control voltages to control the actual displacement of the diaphragm, thereby preventing excessive excursion and overheating, and enhancing bass output through nonlinear control of cone motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the loudspeaker size is reduced for portability, then the device becomes more portable, but nonlinear audio distortion increases and bass output decreases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the control voltage parameters to compensate for nonlinear distortion. The controller modifies the electrical parameters (voltage, frequency) in real-time based on the physical models of the loudspeaker system, allowing the reduced-size loudspeaker to maintain audio quality by changing operational parameters rather than physical dimensions.
Solution Approach 2:
The patent implements feedback control by using physical models to predict the loudspeaker's response and continuously adjusting the control voltage to compensate for nonlinear distortion. The controller receives feedback about the actual displacement and sound pressure, compares it with target values from the physical models, and generates corrected control signals to minimize distortion in the compact loudspeaker design.
2Weight of moving object
If the loudspeaker size is reduced for portability, then the device becomes more portable, but bass output is reduced
Solution Approach 1:
The patent uses parameter changes to enhance bass output in compact loudspeakers by dynamically adjusting control voltage frequency and amplitude parameters. The physical models enable the controller to optimize electrical parameters for low-frequency reproduction, allowing small loudspeakers to achieve extended bass response through parameter optimization rather than physical size.
Solution Approach 2:
The patent applies dynamics by implementing real-time adaptive control that continuously adjusts operational parameters based on the loudspeaker's actual response. The controller dynamically modifies control signals using physical models to optimize bass output at different frequencies and volumes, enabling the compact loudspeaker to adapt its performance characteristics to maintain strong bass reproduction despite reduced physical dimensions.
3Device complexity
If conventional control is used, then the system is simple, but excessive diaphragm excursion and overheating occur
Solution Approach 1:
The patent implements feedback control to prevent excessive diaphragm excursion and overheating by continuously monitoring the loudspeaker's response and adjusting control voltage accordingly. The physical models enable the controller to predict and limit diaphragm displacement, preventing mechanical damage and overheating while maintaining reliable operation.
Solution Approach 2:
The patent applies preliminary anti-action by using physical models to predict and prevent excessive diaphragm excursion before it occurs. The controller proactively adjusts control voltage to keep diaphragm displacement within safe limits, preventing mechanical damage and overheating before they can occur, thereby ensuring reliability without requiring complex mechanical protection systems.
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 nonlinear control system effectively compensates for nonlinear audio distortion, improves power consumption, and enables bass extension while ensuring mechanical protection of the loudspeaker, resulting in improved performance and reduced distortion.
Implementation Method 1
A nonlinear control system for loudspeaker drivers that uses a controller to determine target displacements and sound pressures based on physical models, generating control voltages to control the actual displacement of the diaphragm
Data Source
AI summary
One embodiment provides a vented box loudspeaker system comprising a speaker driver and a controller configured to receive a source signal for reproduction via the driver, determine a target displacement of the driver and a target sound pressure based on a first physical model of the system, and generate a control voltage based on the target displacement, the target sound pressure, and a second physical model of the system. Another embodiment provides a passive radiator loudspeaker system comprising an active speaker driver and a controller configured to receive a source signal for reproduction via the driver, determine a target displacement of a component based on a first physical model of the system, and generate a control voltage based on the target displacement and a second physical model of the system. In both embodiments, an actual displacement of the driver during the reproduction is controlled based on the generated control voltage.