Today I want to talk to the “other”-casters out there… the web- net- pod- [insert your favorite prefix here]-casters. Traditional radio broadcasters already know this stuff, but it may be new to the “new media” folks.
When you listen to most radio programs, the announcer, the commercials, the phone callers, the music, all sound pretty much the same volume. But many podcasts have little or no consistency at all… each new source of audio is at a vastly different volume than the one before. What are the radio people doing to keep the sound consistent?
Most local radio programs are handled by one person, who splits his attention between speaking, setting up the next commercial or song, and mixing the audio. Mixing usually becomes the lowest priority… if any sound at all is coming through, it’s close enough.
This “close enough” audio is sent through an audio processor before it goes to the transmiter. The processor instantly and continuously adjusts the sound to an ideal “target level” that is competitively loud, while at the same time guarding against “clipping” (the harsh distortion that occurs when the sound is louder than the equipment can deal with). This all happens in real time, with no attention from the on-air talent.
I hear you saying “but I can just normalize the audio with my recording software.” Yes you can, if you have the time and patience. Normalizing, equalizing, compressing, and limiting each individual track, and then the complete program, can take a lot of your time. With a broadcast audio processor, “post-production” time is almost eliminated.
Radio broadcast processors can cost over $10K. Fortunately, there are lower-cost options for non-radio use. These are more than simply a compressor-limiter. They provide intelligent gain control, multi-band compression and equalization, and multi-band peak limiting. They also have systems to avoid or reduce the “swirly” background noises often heard on webcasts.
Then there’s always microphone processing to consider… I’ll save that for another time.