Spectral Smear

Parameters

Blur Frames — Number of spectral frames averaged together, 1–100. The “blur radius” — at 1 there’s no smearing (frame passes through unchanged); higher values average more frames together. With 16 frames at hop 1024 / 48 kHz, that’s about 340 ms of smearing, which feels like a soft blur on transients while preserving sustain. Push to 100 for full motion-blur character where transients vanish into a smooth wash.

Mix — Equal-power blend between dry (0) and the smeared signal (1). Lower values blend the original transients back in so the smear sits underneath rather than replacing them.

Output Gain — Output level in dB, −24 to +12. Smearing tends to slightly attenuate peaks (since transients get averaged out), so this brings the level back up.

Additional controls

Shape — Smearing kernel shape. Box — simple uniform average across frames; the most surgical, predictable smear. Gaussian — bell-shaped weighting (heavier at the center frame, lighter at edges); smoother, more natural blur character. Exponential — heavy weighting on the current frame, lighter weighting back in time; produces a “trailing tail” character — the current moment is mostly preserved with a subtle echo trail behind.

Direction — Direction of the smear. Forward — smears forward in time only (current frame averaged with future frames; produces a “look ahead” pre-echo character). Backward — smears backward (current frame averaged with past frames; produces a trailing reverb-like smear, the most natural-sounding choice). Symmetric — smears equally in both directions (the most “stationary blur” — current frame surrounded by neighbors). Backward is the safest default; Forward and Symmetric have specific creative uses.

Preserve Transients — When on, transient frames are detected and protected from smearing — they pass through with their attack intact while the rest of the signal blurs around them. Useful for “smear the sustain, keep the transients” effects. Off blurs everything uniformly.

Transient Threshold (dB) — When preserve_transients is on, this sets the dB threshold above which a frame is considered transient and protected from smearing, −60 to 0. Higher (less negative) values protect only the loudest hits; lower (more negative) values protect more frames including subtler attacks.

About Spectral Smear

Spectral Smear is “motion blur for audio” — where motion blur in video averages adjacent video frames to convey movement, this averages adjacent spectral frames to convey time-domain blur. The result depends on blur_frames: small amounts produce subtle softening (great for taming overly-clicky transients); medium amounts produce a clear smearing/diffusion effect (useful for ambient and dreamy textures); large amounts approach a frozen-spectrum character (each frame is so smeared that the output stops changing). Pair with preserve_transients to keep transient definition while smoothing sustained content. The shape and direction options let you customize the smear character — Backward Gaussian is the most natural-feeling combination; Forward Box gives the most clearly artificial pre-echo character.

Generated 2026-05-05 from K2K_Dev@96730bdc by scripts/gen_lexique.py. Edit _intros/ or _overrides/, not this file.