bass-foundry/docs/planish/README.md

# Planish

Planish is upward and downward compression (OTT) in four bands whose edges are
harmonic numbers of the played note. Current version **0.2.0**.

Planishing hammers a metal surface smooth and even. OTT does the same to a bass:
it pushes loud bands down and lifts quiet ones, and it is on almost every riddim
patch. A normal OTT splits the bands at fixed frequencies, though. A split at
88 Hz and 2.5 kHz puts harmonic 2 of F1 in the low band but harmonic 2 of C2 in
the mid band, so the same setting squashes different harmonics on every note.
Planish moves its band edges with the note: with the default split, band 1 is
the fundamental, band 2 harmonics 2–4, band 3 harmonics 5–16 and band 4
everything above, on F1 as on G2.

![Planish](assets/editor.png)

## Install on Windows

Copy `Planish.clap` into `C:\Program Files\Common Files\CLAP\`. In FL Studio
2024.1 or newer, open Options → Manage plugins, enable Verify plugins, and Find
installed plugins. Load Planish in a mixer slot of the bass. Keep the font
license with redistributed packages.

## Work with it

The editor opens on the **MAIN** page with the split, Drive, Depth, Upward,
Downward, Time and Output. The **ADVANCED** switch in the header adds the band
gains, Smooth, Gate and Snap.

1. Play the bass. The note readout shows what Planish tracks. The ruler at the
   top shows harmonics 1–64 and the four bands; the columns below show each
   band's level (steel) and gain (pink for a cut, blue for a lift).
2. Choose a split, or drag an edge on the ruler:
   - **Classic** (1, 2–4, 5–16, 17+, the default): fundamental on its own.
   - **Sub + body** (1–2, 3–6, 7–24, 25+): the octave stays with the sub.
   - **Tight** (1, 2, 3–8, 9+): close control of the first harmonics.
   - **Wide top** (1, 2–3, 4–32, 33+): one big mid band, the top is fizz only.
3. Set the amount:
   - **Depth** blends each band with its compressed copy. 0 % is a clean sum
     of the bands; the default is 50 %.
   - **Drive** moves the band levels against the thresholds: more drive, more
     squash. It does not change the level by itself.
   - **Upward** and **Downward** scale the two directions. Downward pushes a
     band above −30 dB down at about 20:1; Upward lifts a band below −42 dB at
     about 4:1, by at most 24 dB.
   - **Time** scales every attack and release. Lower bands are slower: at
     100 %, attack is 30, 15, 8 and 4 ms and release 200, 160, 120 and 90 ms
     from band 1 to band 4.
4. On the ADVANCED page, **Band 1–4** set each band's gain after its compressor. Like the
   compression, they are scaled by Depth.

**Output** trims the level. **Bypass** crossfades to the delayed dry signal.

### Pitch source

**Pitch from** in the header chooses where the note comes from: **AUDIO**
detects it, **MIDI** follows MIDI notes sent to Planish, and **NOTE** uses a note
you set. For heavy FM, formant or noise basses, NOTE with the drop's root is the
safest choice. Key lock and Follow bends tune the detection. While detection is unsure of the note, the band edges hold on the last sure note and the readout shows **?**. See
[Pitch source](../pitch.md).

**Gate** (ADVANCED page) sets the input level that counts as a note in AUDIO
mode. **Snap to semitone** rounds the detected pitch; it is off by default,
because the level is measured over one period of the pitch in use, and a
detuned patch fits its real period better.

## Measured

- At Depth 0 the bands sum flat: sines from 35 Hz to 12 kHz come out within
  0.05 dB.
- The same setting changes the same harmonics on every note. At Depth 100 %
  on a saw bass, harmonic 1 is cut by 13.6 dB on F1, C2 and G2; harmonics 1–12
  differ by less than 0.2 dB between the three notes.
- No ripple at the fundamental. A 40 Hz sine at Drive +12 dB and Time 10 % gets
  no harmonics above −110 dB.

## Timing and limits

Planish delays the audio by about 67 ms of pitch-detection lookahead and
reports it to the host for delay compensation, so the edges are on the new note
when its attack leaves the plugin. Pitch range is 30–500 Hz, one note at a time.
Before the first note the edges sit on 55 Hz; between notes they hold the last
note. On a new note the edges slide to it over 6 ms, so the crossovers do not
click.

An edge is a slope, not a wall. The crossovers are 24 dB per octave, so the
harmonics next to an edge partly reach the next band, by the same amount on
every note. Both channels get the same gain per band, so the stereo image does
not move. Quiet signals below about −84 dB are not lifted, so noise floors and
tails stay down.

Planish detects the pitch like Lathe and Temper. Put it before Knurl, or use
MIDI: see [Signal chain](../chain.md).

## How it works

A note tracker (shared with Anvil, Lathe, Temper and Knurl) detects pitch and
note starts ahead of the delayed audio. Three Linkwitz–Riley crossovers split
the signal at √(k(k+1)) × f0, halfway in log frequency between harmonic k and
k+1, and allpasses keep the lower bands in phase with the upper ones, so the
bands sum to an allpass. The crossovers retune every 16 samples and glide with
**Smooth** on bends. Each band's level is the RMS over exactly one period of
the note, so a steady note gives a steady level and the gain does not wobble
at f0. The level goes through attack and release smoothing, then a static
curve with an upward and a downward threshold sets the gain.