Audio Mastering Glossary: LUFS, True Peak, LRA, Dithering, and More

Mastering comes with plenty of technical vocabulary that can trip up newcomers. This glossary breaks down the most important terms you need to know for professional-sounding results, with practical context for each one.

LUFS

LUFS (Loudness Units relative to Full Scale) is the standardized scale of perceived loudness used by streaming platforms and broadcast standards alike. Unlike a peak meter, LUFS reflects how the human ear perceives loudness over the course of an entire track. Read more in What Is LUFS?

dBFS

dBFS (decibels relative to full scale) measures a digital signal's level, where 0 dBFS is the theoretical maximum sample amplitude. Negative values show how far below that maximum a signal sits. dBFS says nothing about perceived loudness — it's purely a measure of amplitude.

True Peak (dBTP)

True Peak (sometimes written dBTP) measures the peaks that appear from interpolation between samples, especially when a file is converted to MP3 or AAC. The recommended ceiling of −1 dBTP prevents clipping introduced by that encoding. More detail in What Is True Peak?

LRA (Loudness Range)

LRA is a track's overall dynamic range, measured in loudness units. It's the gap between the quiet and loud sections of a track. Low LRA (2–4) means a tight, compact sound; high LRA (8–12) preserves more life and dynamics.

Headroom

Headroom is the gap between a track's peak level and clipping (0 dBFS). Reasonable headroom (typically −1 to −3 dBFS) prevents digital clipping during processing. In mastering, headroom is kept in reserve for additional processing and as a safety margin when exporting to different codecs.

Compression

Compression is dynamics processing that reduces the amplitude of the louder parts of a signal. Key parameters: Ratio (how much reduction), Threshold (where it kicks in), Attack (how fast it engages), and Release (how fast it lets go). Compression is the primary tool for controlling dynamics and shaping LRA. Learn about multiband compression in our Multiband Compression Guide.

Limiter

A limiter is a compressor with an effectively infinite ratio (∞:1) that stops a signal from ever exceeding a set threshold. On the master bus, a limiter prevents clipping and guarantees the track doesn't exceed its target True Peak (typically −1 dBTP).

Dithering

Dithering adds a very low-level noise before reducing bit depth (for example, exporting from 24-bit to 16-bit). It improves sound quality in low-amplitude passages and minimizes quantization artifacts. Most modern software applies dithering automatically on export.

Equalization (EQ)

Equalization boosts or cuts specific frequency ranges in a signal. Common types include shelving, peaking, and high-pass/low-pass filters. In mastering, EQ balances the overall spectrum, removes unwanted noise, and emphasizes the frequencies you want to stand out. Magic Master's 17 genre presets automatically apply an appropriate EQ curve for each style.

Multiband Compression

Multiband compression applies compression independently to separate frequency bands. For example, you can compress the bass harder than the vocal without touching the mids or highs. It's a powerful tool for precise dynamics control and clarity — see the full Multiband Compression Guide for details.

Crossover

A crossover is a filter that splits a signal into multiple frequency bands (low, mid, high). It's used in multiband compression and multiband EQ to process different ranges independently. Crossover quality affects artifacts and phase shifts.

Mid-Side (M/S) Processing

Mid-Side processing splits a signal into Mid (the centered mono content) and Side (the stereo difference). This lets you process center and side elements independently — for example, tightening bass in the center while widening vocals in stereo. It's useful for controlling stereo image in mastering.

Stereo Image

Stereo image describes how elements are positioned across the stereo field, from fully left to fully right. In mastering, stereo image control balances mono content (bass, kick) against stereo content (vocals, pads). A well-controlled stereo image adds clarity and a sense of width.

Saturation

Saturation is nonlinear processing that adds harmonics and gently softens peaks, producing a "warmer," denser sound. It's often used on vocals, bass, and drums to add character. Subtle saturation on the master bus can help glue a mix together.

Crossfade

A crossfade blends two sounds by simultaneously lowering the volume of one while raising the other. In mastering, crossfades are used sparingly, but they matter when blending transitions between sections of a track or automating effects.

Oversampling

Oversampling temporarily increases the sample rate (for example, from 44.1 kHz to 192 kHz) for more accurate calculation of nonlinear processing like compression, limiting, and saturation. It reduces aliasing and improves processing quality, at the cost of more computation. Magic Master uses this technique internally.

Gain Compensation

Gain compensation automatically lowers a processed signal's output level so you can compare it fairly against the unprocessed version. Without it, processed audio simply sounds louder — which can trick your ears into thinking it sounds better when it's really just louder.

Phase Shift

Phase shift is the timing difference between two versions of the same signal, usually introduced by filtering or processing. Large phase shifts can create noticeable artifacts and reduce clarity. When using a crossover, it's important to choose linear-phase filters to minimize this effect.

AI Mastering

AI mastering applies processing — compression, EQ, limiting, True Peak control — automatically, using neural network models trained on professional masters. Magic Master uses AI to analyze your track and choose optimal settings in about 20 seconds, saving time and making professional results accessible to everyone.

Conclusion

Understanding these terms will help you evaluate your own sound and make more informed mastering decisions. If you're just getting started, begin with LUFS and True Peak, then work your way into more advanced techniques. Use the LUFS analyzer to check your tracks, and let Magic Master handle the heavy lifting for a fast, professional result — whether you're mastering pop, EDM, hip-hop, or podcast content.