THE AUDIO
GLOSSARY.

Stem Mastering

Stem mastering masters a track from a small number of instrument groups (stems) — typically drums, bass, music, and vocals — instead of a single stereo file. The extra separation lets the engineer rebalance elements and solve problems that can't be fixed on a summed stereo mix, making it a middle ground between stereo mastering and a full mix.

Headroom

Headroom is the gap between the loudest peak in your mix and 0 dBFS (digital full scale). Leaving 3-6 dB of headroom on your mix bus before mastering gives the mastering chain room to process — EQ, compression, and limiting all change level, and a mix that's already slammed against 0 dBFS leaves nowhere to work.

Dithering

Dithering adds a tiny, carefully-shaped layer of noise when reducing bit depth (for example 24-bit to 16-bit for CD or some distributors). It randomizes quantization errors so quiet fades and reverb tails stay smooth instead of developing gritty digital distortion. Apply it once, as the very last step, only when actually reducing bit depth.

Mastering

Mastering is the final stage of music production — the polish applied to a finished mix to make it loud, cohesive, and consistent across every playback system. It sets the final tone, loudness, and stereo image so your track translates from studio monitors to club systems to phone speakers and holds up next to commercial releases.

LUFS

LUFS (Loudness Units relative to Full Scale) measures how loud a track actually sounds to human ears, not just its peak level. Streaming platforms normalize to a LUFS target — Spotify and YouTube to about -14 LUFS — so mastering to the right LUFS is how you control loudness after normalization.

True Peak

True peak (dBTP) measures the actual analog peak a signal reaches after digital-to-analog conversion, including inter-sample peaks that sit between samples. It can run 1-3 dB higher than the sample peak your DAW shows. Master to a -1 dBTP ceiling so streaming codecs and consumer DACs don't clip.

Clipping

Clipping happens when a signal exceeds the maximum level a system can handle, so the peaks get flattened off. Digital clipping produces harsh distortion and is usually a mistake. But controlled clipping — used deliberately before the limiter — is also a modern loudness tool that shaves peaks so the master can go louder cleanly.

Loudness Normalization

Loudness normalization is how streaming platforms play every track at a consistent perceived volume: they measure a track's loudness in LUFS and turn louder masters down (and sometimes quieter ones up) toward a target, about -14 LUFS on Spotify and YouTube. It ended the loudness war by making raw loudness pointless.

Limiter

A limiter is a fast compressor with a very high ratio that stops a signal from exceeding a set ceiling. In mastering, a brickwall limiter is the final stage — it raises overall loudness while catching peaks so nothing clips. Push it too hard and you crush transients and add distortion, so it's about finding the loudest clean setting, not the loudest possible.

Dynamic Range

Dynamic range is the difference between the quietest and loudest parts of a track. Wide dynamic range keeps transients punchy and lets a chorus hit harder than a verse; narrow (heavily compressed) range sounds consistently loud but can feel flat and fatiguing. Good mastering controls dynamic range without destroying it.

Multiband Compression

Multiband compression splits the signal into frequency bands (for example lows, mids, highs) and compresses each independently. It lets you tame a boomy low end or harsh highs without pumping the whole mix, making it a precise tool for mastering and for controlling problem frequencies that a full-band compressor would over-react to.

Sidechain Compression

Sidechain compression uses one signal to trigger compression on another. The classic use: the kick drum ducks the bass (or the whole mix) every time it hits, so the kick punches through cleanly. It's both a mixing fix for kick-bass clashes and a creative pumping effect central to house, EDM, and modern pop.

Compression

Compression reduces the dynamic range of a signal — it turns down the loudest parts so the quiet and loud sections sit closer together. This makes a track sound more even, controlled, and often louder and punchier. It's one of the most used and most misunderstood tools in mixing and mastering.

Saturation

Saturation adds subtle harmonic distortion that emulates analog gear — tape, tubes, transformers, consoles. It makes sounds feel warmer, denser, and louder without raising the peak level, because it adds harmonics rather than gain. Used gently across a mix or master, it's the difference between a clean-but-sterile record and one with analog character and glue.

Equalization (EQ)

Equalization (EQ) adjusts the balance of frequencies in a signal — boosting or cutting specific ranges like the lows, mids, or highs. It's the primary tool for shaping tone: removing mud, adding air, carving space so instruments don't clash, and making a mix sound clear and balanced across the frequency spectrum.

Reverb

Reverb is the effect that recreates the sound of a space — the wash of reflections you hear in a room, hall, or plate. In a mix it adds depth, dimension, and glue, placing elements at a believable distance and making a dry recording feel like it exists somewhere rather than in a vacuum.

Mid/Side (M/S) Processing

Mid/side processing splits a stereo signal into a mid channel (what's common to both speakers — usually vocals, kick, bass, snare) and a side channel (what differs — usually reverb, wide synths, stereo effects). Processing them independently lets you EQ, compress, or widen the center and the sides separately for precise stereo control.

Stereo Imaging

Stereo imaging is the perceived width and placement of sounds across the left-right field. Good imaging makes a mix feel wide and three-dimensional while keeping the important elements — vocal, kick, bass, snare — anchored in the center. Over-widening can sound impressive on headphones but collapse or go hollow in mono.

Mono Compatibility

Mono compatibility means a mix still sounds right when its left and right channels are summed to a single channel. Club systems, phone speakers, and many Bluetooth devices play essentially in mono, so a mix that collapses in mono (vanishing leads, hollow drops) fails on exactly the systems dance music lives on.

Gain Staging

Gain staging is setting the level at each point in your signal chain so every plugin and channel receives an optimal input — not too hot, not too quiet. Proper gain staging keeps analog-modeled plugins in their sweet spot, prevents cumulative clipping, and gives you consistent headroom from the first insert to the master bus.

De-esser

A de-esser is a frequency-specific compressor that tames harsh sibilance — the 's', 't', 'sh', and 'f' sounds in vocals that spike in the 5-10 kHz range. It reacts only when those frequencies get too loud, smoothing them without dulling the rest of the vocal. Uncontrolled sibilance is one of the fastest tells of an amateur vocal mix.

Mixing

Mixing is the stage of production where the individual tracks in a song — drums, bass, vocals, synths — are balanced into one cohesive stereo recording. Using level, EQ, compression, panning, and effects, the mix engineer makes every element sit in its own space so the song sounds clear, punchy, and intentional.