Richard -
Are you sure the noise floor in the room is only coming from the PC? Often times there is air conditioner rumble, especially if you're in an office building, and machine noise from other rooms vibrating through the walls and ceilings.
In a way, it doesn't matter where the noise is coming from. The important thing is to isolate the noise floor (from points in the clip where the speaker is silent - which you're doing), and then remove it from the audio.
The
frying noise you're talking about - could this be a battery in the mic on its' way out, or is it just a cheap lav mic? Another thing to check is the gain on your mic while you're recording - is that coming through a mixer with a master volume? You might be introducing noise there as well. There will always be some noise in the audio, due to ambient sources and RF interference, and a million other possibilities. The key is to track down the ones you can control
before you record, and remove the ones you can't in post. Since every audio recording situation is different (unless you're in a studio), and mics are all over the place as far as signal/noise ration, there is no useful number in db to give you.
Joe Bourke
Owner/Creative Director
Bourke Media
http://www.bourkemedia.com
