Loudspeaker Control Device for Distortion Reduction and Membrane Protection
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Solution Overview
Problem
Loudspeakers introduce non-linear distortion due to magnetic circuit non-linearity and mechanical elements, leading to thermal compression and potential membrane damage from excessive displacements, which existing control solutions do not adequately address.
Innovation Solution
A control device for loudspeakers in an enclosure that processes audio signals to reduce distortion by generating a control signal through separate processing units for different frequency bands, limiting excursion and current/intensity to prevent membrane damage and thermal issues, while optimizing signal reproduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the loudspeaker is supplied with high power to improve sound reproduction quality, then the acoustic signal intensity is improved, but thermal compression occurs due to increased conductor temperature and resistance
Solution Approach 1:
The control device predicts future current values and takes preventive action before thermal damage occurs. By calculating predicted current values based on historical data and encoder feedback, the system attenuates the control signal in advance when thermal compression is detected, preventing temperature-related distortion before it affects sound quality.
Solution Approach 2:
The system uses encoder feedback to continuously monitor the loudspeaker's actual position and velocity, comparing these with predicted values to detect thermal compression effects. This feedback loop enables real-time adjustment of the control signal to compensate for temperature-induced resistance changes, maintaining optimal performance while preventing damage.
2Productivity
If the loudspeaker membrane is allowed to displace excessively to reproduce low frequencies, then the acoustic output is improved, but the membrane may be damaged
Solution Approach 1:
The control device predicts future membrane displacement and velocity based on encoder feedback and attenuates the control signal in advance when excessive displacement is anticipated. This preventive approach allows the system to maintain high acoustic output while preventing membrane damage by limiting excursions before they become harmful.
Solution Approach 2:
The system dynamically adjusts the control signal attenuation based on real-time encoder feedback about membrane position and velocity. By continuously adapting the attenuation level according to actual operating conditions, the system maximizes acoustic output within safe displacement limits, preventing membrane damage while maintaining productivity.
3Measurement precision
If existing control solutions are used to reduce distortion, then signal reproduction accuracy is improved, but protection of the loudspeaker membrane from damage is insufficient
Solution Approach 1:
The control device incorporates predictive attenuation that acts before membrane damage can occur. By predicting future displacement based on encoder feedback and attenuating the control signal in advance, the system maintains high signal reproduction accuracy while providing superior membrane protection compared to existing solutions.
Solution Approach 2:
The system uses encoder feedback to continuously monitor membrane position and velocity, enabling real-time detection of conditions that could lead to damage. This feedback mechanism allows the control device to maintain accurate signal reproduction while actively protecting the membrane by adjusting attenuation based on actual operating conditions.
4Reliability
If the control signal is attenuated to prevent thermal compression and membrane damage, then reliability is improved, but the sound reproduction quality may deteriorate
Solution Approach 1:
The system dynamically adjusts control signal attenuation based on real-time encoder feedback about membrane position, velocity, and predicted thermal conditions. By continuously adapting the attenuation level to actual operating conditions, the system maintains high sound reproduction quality while providing reliable protection, avoiding excessive attenuation that would degrade audio performance.
Solution Approach 2:
The control device changes the attenuation parameter dynamically based on predicted thermal compression conditions and actual membrane displacement. By adjusting the attenuation level according to specific operating conditions rather than applying fixed attenuation, the system preserves sound reproduction quality while maintaining reliable protection against thermal and mechanical damage.
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 control device effectively reduces signal distortion and protects the loudspeaker membrane by limiting excursion and voltage/current, thereby improving sound reproduction quality and extending the lifespan of the loudspeaker.
Implementation Method 1
Loudspeakers are electromagnetic devices that convert an electrical signal into an acoustic signal
Implementation Method 2
the loudspeaker comprises at least one coil
Data Source
Figure 1~2
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AI summary
The present invention relates to a control device (22) for a loudspeaker in an enclosure, the device (22) comprising: - a unit (36) for duplicating a desired dynamic signal (Sdyn) to obtain two identical desired dynamic signals (Sdyn1, Sdyn2), - a first processing unit (38) configured to process the first desired dynamic signal (Sdyn1) to obtain a first processed signal (Sdyn1') whose frequencies are less than or equal to a predetermined frequency, - a second processing unit (40) configured to process the second desired dynamic signal (Sdyn2) to obtain a second processed signal (Sdyn2') whose frequencies are strictly greater than the predetermined frequency, and - a combining unit (42) of the first and second processed signals (Sdyn1', Sdyn2') to obtain a control signal (Scommande) for the loudspeaker.