自动增益控制（AGC），用于外部麦克风 [英] Automatic Gain Control(AGC) for external mic
问题描述
我有记录使用PCM-WAV格式的Android市场上的录音应用。
我的应用程序还提供了自定义的增益控制（[-20dB，○分贝]），所以我改变与用户选择的增益值的原始音频数据。
I have an audio recording app on android market which records using PCM-WAV format.
My app also offers custom gain control ([-20dB, +20dB]), so I alter the original audio data with user selected gain value.
它的工作原理pretty以及使用设备内置的麦克风时，但我有一个使用插入到他的设备的某些外接MIC用户，输出太响，充满扭曲的（因为他的分机话筒响度）。甚至当他将增益设置为-20dB，输出是响亮而包含的扭曲。
It works pretty well when using device built-in mic, but I have a user which uses some external mic plugged into his device, and the output is too loud and full of distortions (because of the loudness of his ext mic). Even when he set the gain to -20dB, the output is loud and contains distortions.
我想我应该补充AGC控制到应用程序的情况下，因为这。
I thought I should add AGC control into the app for cases as this.
现在我的问题：
使用设备内置的麦克风时，该AGC仅适用？或使用插入到一个手持话筒分机时，也适用？
推荐答案
这是很可能的是，真正的问题是，他的麦克风过驱动输入插孔 - 如果是这样的话，软件无法修复的问题，因为什么A / D转换器看到的是绝望已经扭曲。
It's quite likely that the real problem is that his microphone is overdriving the input jack - if that is the case, software can't fix the problem as what the A/D converter sees is already hopelessly distorted.
您客户可能需要一个衰减器（电阻分压器）添加到输入信号。
Your client may need to add an attenuator (resistive voltage divider) to the input signal.
此外，如果输入信号是不对称的，可能通过串联电容，以阻止任何DC分量是必要的耦合。
Also, if the input signal is asymmetric it may be necessary to couple through a series capacitor to block any DC component.
做一个记录，没有增益，并研究在诸如大胆的音频编辑器产生的波形很可能是资料性的。
Doing a recording with no gain, and examining the resulting waveform in an audio editor like audacity would probably be informative.
（通常我不会发布这个东西作为投机性的答案，但specificaly要求从原来的产品作为注释转换为一个）
(Normally I would not post something this speculative as an answer, but was specificaly asked to convert it to one from its original offering as a comment)
这篇关于自动增益控制（AGC），用于外部麦克风的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
