Pop filters are vital in the recording process mainly because microphones don’t work like human ears. Microphones “hear” different sounds than we do, and one of those things is the blast of air that comes when singers make certain sounds.
Human ears work by picking up on pressure differences in the eardrum. Air blasts aren’t strong enough to put pressure on the drum, so we hear them as a hissing noise.
Mics, however, are totally different. A microphone hears with a thin piece of metal foil that vibrates. It can’t tell the difference between types of vibration. If you blow on it, it thinks it’s just getting hit with a giant wall of sound. This comes out in the track as a loud pop that often ruins the recording.
This effect is even worse for studio mics, since they’re designed for sensitivity and sound depth. They hear everything well, meaning they pick up on even small air blasts.
Why Pops Happen
No one thinks they’re blowing on their mics. But singers are, all the time, because the English language has a lot of sounds we call “plosives.”
The plosives are sounds we make by pushing air out of our lips, explosively. If you put your hand in front of your mouth and say “button up your all-star jacket,” you’ll feel the air on the “b”, “p” and “t”, but not so much on the “l”, “r”, and “k.”
How Pop Filters Work
A pop filter has two jobs:
- Blocking the air from plosives.
- Letting the sound pass through without any changes.
These jobs aren’t difficult. Most cheap or DIY pop filters work out great, stopping all pops without affecting the rest of the sound.
Choosing a Pop Filter
Pop filters are incredibly cheap, as far as recording gear goes. Most use a vinyl mesh that scatters air blasts. The vinyl ones are good for starters, but can slightly dampen the high-end. Pros tend to go with metal mesh. The metal mesh models can scatter the air, but take a little bit more vocal control to use properly.
Making Your Own Pop Filter
Pop filters are cheap, but if you’re just the kind of person who DIYs everything, they’re also easy to make. Use a single sheet of stocking nylon, stretched across a circular frame. You can use any kind of frame; we’ve even seen ones made from plastic rings purchased at toy or dollar stores!
If you want to go the metal mesh route, a metal kitchen colander works great. All you have to do is figure out a way to hold it in place.
Whether you make or buy a pop filter, make sure you do it before you start serious recording!