Guest post by Daan Berg
There are many local radio stations in the Netherlands, 285 to be exact. I am a volunteer at one of these stations, where I produce and present a live weekly breakfast-with-news show every Saturday morning.
However, sometimes I need to cheat, when I need to be somewhere else during broadcast hours. Therefore, whenever I can't make a live show, I pre-record it and upload the three hours of material to the control room server, which plays the recordings during my broadcast hours as if I were there, talking live and playing music to my listeners.
I do my recording in a small studio booth in the cozy building of the combined radio and television station, in which all the professional equipment -- from audio mixers and microphones to professional recorders -- are installed. I can plug my laptop into an outlet of the mixer and start recording, which usually works fine. But recently, things went wrong.
I had just finished recording three hours of great radio with lots of enthusiasm, which one always needs when hosting any kind of show. I opened up WavePad which I always use for audio editing, to cut off the silences at the beginning and end of the files and listen if everything sounded OK. It didn't. What happened?
It turned out the internal sound processor of the audio mixer, the boards full of sliders and knobs you always see in front of radio producers, had its limiter set to a way too aggressive setting. Limiting is the act of bringing the volume of a device down quickly when it's too loud. For instance, you will notice that if you bring a microphone close to your mouth and shout into it, you will hear that your speakers can't cope. However, radio hosts shout into microphones from time to time. On the radio, it is very rare to hear this, as the limiter in the control room will automatically pull the volume of the microphone down to make sure no gear is damaged and to make the sound more enjoyable.
However, a limiter can also be set too aggressive. Instead of only pulling down peaks that go above a certain maximum level, a limiter can also see every peak as a peak that's too loud. The result: a recording with terribly annoying volume changes every tenth of a second, like someone is heavily abusing the volume knob on a radio.
So I was stuck with three hours of material that I couldn't use. Until I remembered that WavePad has an Automatic Gain Control function, which analyses the volume of the audio file and makes adjustments where needed.
It most certainly worked! Of course, the result wasn't perfect yet -- software can never 100% undo what was done with analog equipment -- but when the edited files were played back through the central server, it sounded fine. This had to do with the fact that the control room also sports a compressor, which is a machine that does the opposite of a limiter; it increases the volume when it's too soft.
Thanks to WavePad Audio Editor, I didn't have to start recording all over again. If I had done it all over with my enthusiasm completely gone it would've sounded terrible.
Daan Berg is a local journalist in the Netherlands. He writes for a national newspaper and hosts a weekly breakfast radio show on local radio. He also makes all kinds of media productions, from radio & television items and shows to websites.