What is the difference between LUFS and dBFS peak?

dBFS (Decibels relative to Full Scale) measures instantaneous peak amplitude without considering human perception. LUFS (Loudness Units relative to Full Scale) measures integrated perceptual loudness over time using K-weighting filters that account for human hearing sensitivity across different frequencies.

Why does my master distort on 808 sub-bass when limited?

Low frequencies have long physical wavelengths. A 40Hz sub-bass note takes 25 ms per single cycle. If your limiter release is set to 15 ms, the limiter modulates the individual peaks and valleys of the sine wave, converting a clean sine into a distorted square wave. Keep release times > 35 ms on sub-heavy tracks.

Should I use Auto-Release on my mastering limiter?

Modern limiters (like FabFilter Pro-L 2, Ozone Maximizer, Weiss MM-1) feature advanced program-dependent auto-release algorithms that use ultra-fast release for brief transient snare hits and slower release for sustained sub-bass. However, manually verifying tempo-synced timing remains the gold standard for dance, techno, and pop.

Will Spotify turn down my song if it is mastered to -9 LUFS?

Yes. Spotify normalizes music to -14 LUFS Integrated by default (with Loudness Normalization turned on in user settings). If your master is -9 LUFS, Spotify will simply attenuate the playback volume by 5 dB. The track will not be damaged, but it will sound identical in volume to a master with higher dynamic range.

Why should I use a clipper before the final peak limiter?

Using a transparent soft clipper (like StandardCLIP or KClip) to shave off 1 to 2 dB of unnoticeable snare and kick transient spikes prevents the peak limiter from having to work too hard, preserving high-end punch and avoiding limiter pumping.

Free Audio Limiter Threshold & Release Tempo Calculator

🎛️ Song Tempo & Loudness Targets

Song Tempo (BPM) e.g. 124 for House / EDM

Release Note Value

Current Mix LUFS (Integrated) Unmastered mix loudness

Target Master Loudness

True Peak Ceiling (dBTP)

Lowest Bass Sub Freq (Hz) Determines min distortion-free ms

⚡ Limiter Settings & Distortion Safety

Tempo Synced Release -- Milliseconds (ms)

Limiter Drive / Gain Push -- dB of gain increase

True Peak Output Ceiling --

Minimum Safe Release (No Sub Distortion) --

Triplet Sync Alternative --

Dotted Sync Alternative --

Dynamic Crest Factor Estimate --

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The Mathematics of Mastering Peak Limiters and Streaming Targets

The final peak limiter in an audio mastering signal chain serves two crucial purposes: catching rapid inter-sample transients to prevent digital clipping, and increasing perceived acoustic loudness (LUFS) to match commercial industry standards. However, dialing in incorrect limiter attack and release times creates catastrophic side effects—either destroying transient punch and causing unnatural "breathing" pumping, or generating harsh harmonic buzzing across 808s and sub-bass synthesizers.

Why Limiter Release Must Match Song BPM

When a kick drum or snare hits the limiter threshold, the gain reduction circuit immediately attenuates the audio level. How fast the limiter releases (recovers back to unity gain) determines the groove and transparency:

Too Fast: If the release time is shorter than one-half of a bass waveform's period (for a 50Hz sub, a single wave takes 20 ms), the limiter opens and closes within a single cycle of the sine wave. This wave-shaping distortion sounds like gritty, buzzy square-wave distortion.
Too Slow: If the release time is overly sluggish (e.g. 300 ms on a 130 BPM dance track), the limiter remains pulled down during the subsequent downbeat, sucking the life and dynamic energy out of following instruments (limiter pumping).
Tempo-Synced Sweet Spot: Setting the release to an exact musical note division (such as 1/32 or 1/16 note based on Release ms = (60,000 / BPM) × Note Division) ensures the limiter snaps back to 0 dB gain reduction just in time for the next groove element.

True Peak (ISP) and Streaming Normalization

Standard peak sample meters only measure the value of discrete digital audio samples. When audio is converted back to analog through a DAC (Digital-to-Analog Converter) or compressed into lossy codecs (Ogg Vorbis, AAC, MP3) for Spotify, YouTube, or Apple Music, the reconstructed continuous waveform can rise 0.5 to 1.5 dB higher than the highest digital sample. These are known as Inter-Sample Peaks (ISPs).