what's the difference between microphone gain and microphone “level” and “boost” in Windows?

Question

I have an USB microphone that has a gain control knob. As I understand, the gain here means the voltage amplifier gain inside the microphone. USB microphone will have an maximum output voltage of 5V, so if the gain here is too high, sound might be clipped.

In Windows 7, when you go to microphone properties, you can adjust the mic "level" from 0 to 100, and also mic "boost" in decibels. Can you help me make sense of those two concepts and how they work?

I have an noise evaluation application where the amplitude of the signal is highly important so it'll be good to understand and control these parameters properly.

Thanks

Answer 1

USB microphone will have an maximum output voltage of 5V

No. No microphone has a 5V max output level, microphones use far lower levels. The 5V supplied by USB is irrelevant here.

if the gain here is too high, sound might be clipped

yes.

you can adjust the mic "level" from 0 to 100,

That's in % of maximum input. This is the gain setting.

and also mic "boost" in decibels

This is another gain control, adjustable in 10 dB steps. Use this when setting the mic level to 100 does not produce enough volume.

Use any audio application with a volume meter and waveform display to check and adjust your levels.

• the volume meter shows you if the Windows volume settings are ok
• he waveform display can help you detect clipping in the microphone: if you set the microphone gain too high, the waveform won't be a nice collection of sine waves, it'll be clipped.

Answer 2

"..Gain and volume are very similar concepts, but their difference is very important to your mix. Volume is how loud the OUTPUT of the channel or amp is. ... Gain is how loud the INPUT of the channel or amp is.." LINK