Tutorials Audio

De-Essing Explained

Beginner · ~20 min

Overview

Sibilance (the harsh, whistly "sss" and "sh" sounds in speech) gets worse the closer a mic is placed and the more you compress or brighten a vocal. This guide covers finding the exact problem frequency and setting up a proper de-esser, the natural next step after learning EQ and compression basics.

What You Need

A recorded vocal or dialogue track with noticeable sibilance
A free de-esser plugin (many DAWs include one, TDR Nova and ReaFIR both work as free options)
The site's Vocal Sibilance Finder app to pinpoint the exact frequency

Steps

Find the sibilance frequency by ear

Sibilance typically lives between 5-8 kHz, but the exact peak varies by voice. Some sit closer to 4 kHz, others past 9 kHz. Sweep a narrow EQ boost through that range while listening to an "s"-heavy phrase until it sounds most harsh and piercing.

Confirm it with a spectrum analyser

Use the site's Vocal Sibilance Finder to run an FFT analysis on the track and see the exact frequency band where "s" and "sh" sounds spike. This removes the guesswork from step 1.

Add a de-esser plugin

A de-esser is a compressor that only reacts to a specific frequency band, insert one after your main EQ and compression in the chain, since sibilance often gets amplified by earlier processing.

Set the frequency and threshold

Dial the de-esser's target frequency to what you found in steps 1-2, then lower the threshold until it engages only on the "s"/"sh" sounds specifically, not on every word.

Check in context, not solo

Listen back within the full mix, not soloed, over-de-essing creates a noticeable lisp-like effect that's more obvious in solo than in context, but under-de-essing is more obvious in a full mix. Adjust with both references.

Pro Tips

Sibilance gets worse the closer the mic, if a specific take is unusually harsh, check whether the speaker leaned in during that section.
De-ess before, not instead of, good mic technique. A slight off-axis mic angle reduces sibilance at the source more effectively than any plugin fixes after the fact.
Automate de-esser intensity per section if one part of a recording is much worse than another, rather than setting one aggressive setting for the whole track.

Knowledge Base

Why Sibilance Happens

"S," "sh," "ch," and "t" sounds are naturally high-frequency and high-energy, condenser mics (more sensitive at high frequencies) and close mic placement both exaggerate them further. Compression and bright EQ boosts, both common in podcast and VO chains, make already-present sibilance more prominent rather than creating it from nothing.

De-Esser vs. Standard EQ

A static EQ cut at the sibilance frequency reduces sibilance evenly across the whole recording, including on words that don't have any "s" sounds, dulling the voice unnecessarily. A de-esser only engages dynamically when sibilance actually occurs, preserving natural brightness everywhere else.

Free De-Esser Options

TDR Nova (free, includes a dynamic EQ band that works well as a de-esser), ReaFIR (bundled free with REAPER), and most DAWs' stock channel strips include a basic de-esser. A dedicated paid de-esser plugin is rarely necessary for typical podcast/VO work.

Where This Fits

This guide covers one specific part of mixing and colour. The wider picture. The full mix workflow from gain staging and balance through bus processing and knowing when to stop, is in Mixing a Full Song: From Rough Levels to Final Bounce, which frames the discipline as a whole and links out to the detailed guides underneath it, including this one. If you are starting from scratch rather than solving a specific problem, read that first and come back here.

FAQ

Q: Can I de-ess too aggressively?
A: Yes, over-de-essed vocals develop a subtle lisp-like quality where "s" sounds seem to disappear or lisp rather than sound naturally reduced. Back off the threshold if you hear this.

Q: Should I de-ess before or after compression?
A: After, compression tends to bring up sibilance along with everything else, so de-essing afterward catches the actual post-compression problem rather than guessing at it beforehand.