Dynamic Bass Compression EQ for Small Speaker Distortion Control
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Solution Overview
Problem
Inexpensive speakers in audio and video systems, such as TVs and computers, often have poor low-frequency response and are prone to distortion, failing to meet the audio quality expectations of discerning consumers without the need for additional speakers.
Innovation Solution
A system that enhances the low-frequency response of internal speakers by using a crossover network to separate audio signals into frequency bands, with a signal compressor that provides amplification for low-energy signals and attenuation for high-energy signals to prevent overdriving, while also including a signal summer and peak limiter to protect the speakers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If small inexpensive speakers are used to minimize cost, then manufacturing cost is reduced, but low frequency response quality deteriorates
Solution Approach 1:
A signal compressor is introduced as an intermediary device between the audio source and the small speakers. The compressor dynamically adjusts signal levels, providing gain for low-energy signals to enhance bass response and attenuation for high-energy signals to prevent distortion. This mediator enables inexpensive speakers to deliver improved low frequency performance without requiring additional hardware.
2Manufacturing precision
If signal amplification is applied to enhance bass response, then low frequency response is improved, but speaker distortion increases due to overdriving
Solution Approach 1:
The patent employs dynamic signal processing through a compressor that continuously adapts its behavior based on instantaneous signal energy levels. During low-energy periods, the compressor applies amplification to boost bass response. During high-energy periods, it automatically applies attenuation to prevent overdriving the speakers. This dynamic adjustment resolves the contradiction by making the system's behavior variable rather than fixed.
Solution Approach 2:
The signal compressor monitors the energy level of the low frequency portion of the input signal and uses this feedback to control the amount of amplification or attenuation applied. The compressor responds to the actual signal conditions in real-time, automatically reducing gain when signal energy becomes too high, thereby preventing speaker distortion while maintaining enhanced bass response during normal playback levels.
Data Source
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AI summary
A system for and method of enhancing the low frequency response of a loudspeaker for relatively low input level audio signals and protect the loudspeaker for relatively high input level audio signals is disclosed. The system comprises: a crossover network configured so separate an audio input signal into at least two frequency bands including a low frequency band; and a signal compressor responsive to the energy level of the low frequency portion of an input audio signal in the low frequency band and configured to provide amplification gain on the low frequency portion of the input signal when the energy level of the low frequency portion of the input signal is relatively low so as to enhance the low frequency response of the loudspeaker, and attenuation of the low frequency portion of the input signal when the energy level of the low frequency portion of the input signal is relatively high so as to protect the loudspeaker from being overdriven. The system is configurable so that it can be used to enhance the loudspeakers of audio and video play devices such as televisions and computers.