How do I stop popping Ps and harsh S sounds in a recording?

People reach for a pop filter for both problems and it only solves one. Telling them apart takes one listen: plosives are low-frequency thumps on specific consonants, sibilance is a high, hissy edge on S and T sounds.

Step by step

1. Identify which one you have.Plosives are brief low-frequency thumps that show on the waveform as a sudden bulge, on P, B and sometimes T. Sibilance is a bright, piercing hiss on S, SH, Z and CH sounds, continuous rather than percussive.
2. Fix plosives at the source.Angle the microphone so your mouth is not pointing straight at the capsule — offset it above, below or to one side. This alone removes most plosives, because the air blast is highly directional and your voice is not.
3. Add a pop filter as the second line.A mesh or foam screen five to eight centimetres from the capsule breaks up the air stream. Mesh is generally more transparent than foam, which absorbs some high frequency along with the blast.
4. Use a high-pass filter.Plosive energy sits mostly below 100Hz, which is below the useful range of most voices. A high-pass filter at 80 to 100Hz on a male voice, a little higher on a female voice, removes it along with room rumble and traffic and costs almost nothing audible.
5. Repair individual plosives in editing.For a pop that survived, select just that syllable and apply a steep low cut, or reduce the gain of that fraction of a second. It is a two-second fix per instance and far better than processing the whole track.
6. Understand where sibilance comes from.It is a natural peak in the voice, usually somewhere between five and ten kilohertz, exaggerated by close microphone placement, by bright condenser microphones, and by any compression or high-frequency boost applied afterwards.
7. Move off axis for sibilance too.The high frequencies are the most directional part of the voice, so a small angle change reduces sibilance noticeably while barely affecting the body of the sound. Backing off a couple of centimetres helps as well.
8. Use a de-esser rather than an equaliser.A de-esser is a compressor that acts only on the sibilant frequency band, and only when it is present, so the rest of the voice is untouched. Cutting the same frequencies with a static equaliser dulls the whole recording.
9. Check your processing chain.Compression brings quiet detail up, including sibilance, and any high-frequency boost or exciter makes it worse. If a recording became harsh after processing, the processing is the cause, not the microphone.

Tips

• A pencil taped vertically across the front of the microphone splits the air blast and works surprisingly well as an emergency pop filter.
• Dynamic microphones are generally less prone to both problems than bright condensers, which is one reason broadcasters use them.
• Some people are naturally very sibilant. A microphone with a smoother top end suits them far better than trying to process it out.

Common mistakes

• Using a pop filter to fix sibilance — A pop filter breaks up air movement and does very little to high-frequency content. Sibilance needs placement changes or a de-esser.
• Cutting treble across the whole track — It removes the clarity and air from the voice along with the sibilance, leaving a dull recording. A de-esser acts only when the sibilance occurs.

If it doesn't work

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