Lustre.
mastering room · build 39
totally free — master & filter your songs, no catch

Give machine-made music
its air back.

Totally free mastering and filtering — AI generators render gorgeous songs into a frequency ceiling — the shimmer above ~13 kHz simply isn't there, the low-mids congeal, and the dynamics arrive flattened. Lustre listens first, diagnoses your track, then rebuilds the missing spectrum with harmonic reconstruction — entirely in your browser. Nothing is uploaded anywhere.

Drop a track here, or click to choose
MP3 · WAV · M4A · FLAC — processed locally, exported as 24-bit WAV

The chain

Every stage is tuned by what the analyzer actually hears in your file — not a one-size preset. The order below is the signal path.

01 · Listen

Forensic analysis

Measures integrated loudness (K-weighted), true crest factor, stereo correlation, low-mid congestion, and — crucially — the exact frequency where your generator gave up.

02 · Recognize

Genre brain

Tempo, beat periodicity, sub weight, transient density, spectral flatness and vocal presence feed a classifier that guesses the genre — then reshapes every stage below to match. It shows its guess; you can overrule it.

03 · Clean

Surgical tone

Adaptive cuts in the 400–800 Hz mud and the 5–8 kHz digital fizz, sized to the measurements. A sub-shelf and a low-end harmonic bus restore the weight generators undersell.

04 · Widen

Mid/side field + lush dimension

Bass folds to mono below 130 Hz to kill phase smear, the sides open above it — and a modulated dual-delay dimension engine blooms your mono content out into the stereo field. The big, glossy, Flume-scale width.

05 · Secret sauce

Spectral Bloom

The signature move: upper-mid harmonics are excited through an asymmetric waveshaper and folded back in above the detected ceiling — regenerating real, musical air where the AI left silence.

06 · Breathe

Analog drift

Two sub-audible LFOs gently wobble level and tilt (±0.2 dB, ~8-second cycles), breaking the eerie spectral regularity of generated audio. Your ear reads it as "alive".

07 · Glue

Saturate · compress · limit

Tape-style saturation, a slow glue compressor, a crushed parallel bus for density, then loudness normalization through a lookahead true-peak limiter to your chosen target.

± · Tuning

415 → 444 Hz

Whole-track retune by high-quality resampling — from real Baroque pitch to the solfeggio "528". Honest note: no controlled study shows any tuning is objectively "healing" — but tuning is taste, and the loudness-matched A/B lets your ears judge fairly.

∞ · The booth — coming soon

A resident engineer

Describe the feeling you're chasing in plain words — with lyrics if you have them. The resident engineer reads your track's measurements, reads the song, then sets every fader, vibe, tuning, and texture on this console itself and renders. Prompting, but the output is sound. Opening soon.

± · Texture

Vinyl 45 · tape

Physically modeled patina: vinyl wow at exactly 0.75 Hz (one wobble per 45 rpm revolution) with dust ticks and surface hush, or tape with 60 Hz head bump, hiss and flutter — the noise runs through the glue so it sits in the master, not on top of it.

The console

Diagnosis

Genre brain

Character

choose a destination, then push the fader
100%
concert standard
A = 440.0
no added character
55%
40%
low ride: 0% = punchy & tight (kicks hit the limiter raw) · 100% = silky (the low end rides smooth, no hard ducking on drum hits)
60%
warmth: 0% = fully clean · 100% = deep tape glow · 100–150% = the hot zone: drives past calibration into the thick early-build richness (gorgeous on sustained synths, watch it on sharp drums)

Vibes

pure master — no vibe applied
* = invented here for fun — imaginative sound design, not medicine. every vibe is honest DSP underneath: speed, reverb, echo, filters, width, swell.
calibrated · safe transients · exact loudness

Undertow

no undertow layer
40%
shepherd tones are a genuine auditory illusion. the tone layers* are binaural beats; the weave layers* modulate the spatial field of the music itself — no added tones, the song is the carrier. all need headphones. entrainment evidence stays mixed (40 Hz has the most real research); if the motion ever feels uncomfortable, lower the depth.

The booth

a resident engineer that reads your analysis and lyrics, then dials in the whole console
coming soon
the booth is being wired up — create a free account and you'll be the first to hear when the engineer moves in

The proof

loudness-matched A/B across your last 5 masters — louder never gets to cheat  
bloom zone ↑ reconstructed air
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