# Hessian

> A punchy hybrid voice: a short, clicky transient on every note over a grainy digital tone and a warm low-pass, for plucks and stabs.

- Instrument id: `org.sournd.instrument.hessian`
- Kind: instrument (a synth you play with notes, keys or MIDI)
- Voices: 8 voices
- Tier: Paid
- Version: 0.1.0
- Price: £4.99 once (yours for good, with updates), or in the Synths and Everything plans

## Get it

Buy it once for £4.99 (https://sournd.com/sounds/hessian/, PayPal, no account), or get every synth with the Everything plan (https://sournd.com/pricing/index.md). An AI agent can quote it with the MCP tool `get_price` and start a checkout with `create_checkout`.

## Parameters

| Id | Key | Name | Min | Max | Default | Unit |
|---|---|---|---|---|---|---|
| 0 | `cutoff` | Cutoff | 30 | 18000 | 2000 | Hz |
| 1 | `resonance` | Resonance | 0 | 0.98 | 0.25 | - |
| 2 | `env_amount` | Filter envelope | -1 | 1 | 0.45 | - |
| 3 | `key_track` | Key tracking | 0 | 1 | 0.5 | - |
| 4 | `drive` | Drive | 0 | 1 | 0.1 | - |
| 5 | `filter_attack` | Filter attack | 0.5 | 10000 | 1 | ms |
| 6 | `filter_decay` | Filter decay | 5 | 10000 | 300 | ms |
| 7 | `filter_sustain` | Filter sustain | 0 | 1 | 0.25 | - |
| 8 | `filter_release` | Filter release | 5 | 10000 | 350 | ms |
| 9 | `attack` | Attack | 0.5 | 10000 | 1 | ms |
| 10 | `decay` | Decay | 5 | 10000 | 500 | ms |
| 11 | `sustain` | Sustain | 0 | 1 | 0.6 | - |
| 12 | `release` | Release | 5 | 10000 | 400 | ms |
| 13 | `detune` | Detune | 0 | 50 | 0 | cents |
| 14 | `unison` | Unison | 1 | 7 | 1 | voices |
| 15 | `unison_spread` | Unison spread | 0 | 50 | 10 | cents |
| 16 | `sub` | Sub | 0 | 1 | 0 | - |
| 17 | `noise` | Noise | 0 | 1 | 0.08 | - |
| 18 | `glide` | Glide | 0 | 2000 | 0 | ms |
| 19 | `vibrato_rate` | Vibrato rate | 0.02 | 40 | 5.5 | Hz |
| 20 | `vibrato` | Vibrato | 0 | 100 | 0 | cents |
| 21 | `drift` | Drift | 0 | 25 | 0.01 | cents |
| 22 | `velocity_amp` | Velocity to level | 0 | 1 | 0.35 | - |
| 23 | `velocity_cutoff` | Velocity to cutoff | 0 | 1 | 0.3 | - |
| 24 | `bend_range` | Bend range | 0 | 24 | 2 | st |
| 25 | `width` | Width | 0 | 2 | 1 | x |

## Play it from code

Instruments use the same C ABI as effects, plus note input: `sournd_engine_note_on(e, note, velocity, sample_offset)`, `sournd_engine_note_off(e, note, sample_offset)` and `sournd_engine_all_notes_off(e)`. In JUCE, the bridge feeds your `MidiBuffer` straight in. See the [C ABI reference](https://sournd.com/docs/abi/index.md).