Audio Signal Gain Filtering for Stable Small-Speaker Volume
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic devices with small speakers face challenges in maintaining consistent audio volume due to the limitations of existing Auto Gain Control (AGC) mechanisms, leading to volume fluctuations.
Innovation Solution
A processing system with a Class-D audio amplifier, a decoding module, a filtrating module, and an amplifying module that predefines a cutoff frequency and gain to attenuate and amplify audio signals, ensuring consistent sound output by differentiating between frequencies below and above 600 Hz and applying a preset gain to stabilize sound intensity differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size of the speaker is reduced, then the electronic device becomes more compact, but the audio output volume decreases
Solution Approach 1:
The patent changes the electrical parameters of the audio signal by applying different gain values to different frequency ranges. The amplifying module adjusts the gain parameter based on frequency, boosting high-frequency signals (above cutoff frequency) with a first gain and low-frequency signals (below cutoff frequency) with a second gain, thereby compensating for the reduced speaker output volume while maintaining compact device size
Solution Approach 2:
The patent segments the audio signal into different frequency ranges using the filtrating module, which separates signals above and below a cutoff frequency. This segmentation allows independent gain adjustment for each frequency band, enabling targeted amplification of high-frequency components to compensate for the small speaker's limited output capability without affecting the overall device compactness
2Power
If the Auto Gain Control (AGC) mechanism is used to increase volume, then the audio output volume is boosted, but the volume fluctuates
Solution Approach 1:
Instead of using AGC which dynamically adjusts gain based on overall signal level (causing fluctuations), this patent applies fixed gain values (first gain and second gain) to different frequency ranges. This frequency-based static gain approach eliminates the volume fluctuations inherent in dynamic AGC while still achieving volume enhancement, particularly for high-frequency content
Solution Approach 2:
The patent applies different gain qualities to different parts of the frequency spectrum. High-frequency signals receive a first gain while low-frequency signals receive a second gain, creating localized quality enhancement in the high-frequency range. This local quality approach stabilizes overall volume by avoiding the global dynamic adjustments that cause AGC fluctuations, while still achieving the desired volume boost
Data Source
AI summary
In a method of reproducing audio signals using an electronic device, the electronic device decodes an audio file to generate original digital audio signals, and attenuates the original digital audio signals having frequencies that are lower than a preset cutoff frequency. The electronic device further amplifies each of attenuated digital audio signals and the original digital audio signals having frequencies that are higher than the preset cutoff frequency with a preset gain. Once the electronic device converts the amplified digital audio signals into analog audio signals, and outputs the analog audio signals to an audio amplifier, the audio amplifier amplifies the analog audio signals to drive a speaker to output the analog audio signals.