Audacity Forum

<<<Microphone inputs are massively more sensitive than line inputs>>>

That's not exactly the only difference. Microphones designed to be plugged into a PC are frequently powered from the PC (bottom illustration)...

http://www.kozco.com/tech/audioconnecto ... ctors.html

Those microphones have no sound at all if you plug them in the wrong place, but you do need to keep that in mind because the plugs are the same. The top illustration is what's in your Mac and the difference in volume is on the order of a thousand to one in addition to the stereo-mono thing.


That's a pending experiment here. The Line-In of a Mac is very well behaved and I wondered if, in desperation, I could force a microphone into the Mac and bring it up with the Audacity tools. The noise floor last time I measured it was some -85dB in real numbers. If the mic level is, say, -50dB, that still gives me 35dB of noise floor. Not great, but if I reeeely needed something to work, that might be enough.

It would get better if I yelled and had a microphone with higher natural output. Filter my brains out. Then perform Audacity 1.3 noise reduction....

I need to try that.

Koz

I hope you guys don't mind me bumping this up again but I just a bought a new, USB microphone but the recording is still just as quiet. Well, like before, only recording over music is quiet. Help?

USB microphones are normally quiet because they have no choice. Low sound is easily fixed by several tools inside Audacity, but overload distortion from too loud a signal is permanent and fatal to the show. Since there's no mixer or human intervention during the recording step, low is good.

Capture and production are two steps. Capture low to make sure you get it all in with no damage and then, later, in post production, mix with other clips and segments.

Koz

Some USB microphones include software that allow you to change the sensitivity. Check on the website for your microphone manufacturer to see if they supply such a utility. The effect of such a utility is usually the same as using the "Amplify" effect in Audacity after you have recorded. If a "Sensitivity applet" is not available for your microphone, just record at the default level, then use the Audacity "Amplify" effect on your recorded track. You may notice that the background hiss from the microphone is increased but the "Noise Removal" effect in Audacity can help to improve that. Noise Removal in Audacity 1.3 is much better than in Audacity 1.2.

The recording level from a microphone will be considerably increased by using the microphone closer to the sound source. If you are recording a voice with the microphone close you may want to use a "pop shield" http://www.soundonsound.com/sos/may05/a ... hields.htm or carefully place the microphone so that you do not blow directly onto it.