Component
Diffuseur
v0.5.108
The loudspeakers of the Ondes Martenot.
Software v0.5.108
Overview
The loudspeakers of the Ondes Martenot.
The loudspeakers of the Ondes Martenot, each with its own sound. Principal is the plain cabinet. Palme is a lyre-shaped cabinet with twelve strings that ring in sympathy: a singing halo that carries on after the note. Métallique uses a gong as the speaker cone: metallic, inharmonic overtones that do not follow the pitch.
It is a separate module so that a whole poly patch shares one cabinet, as on the instrument: put it after the voices, typically after a Martenot voice. It also works behind anything else, a piano through the Palme for instance. The fourth speaker of the instrument, the Résonance spring reverb, is the Reverb module in Spring mode placed after it.
Controls
| Control | Range | Default | What it does |
|---|---|---|---|
| Kast | Principal / Palme / Métallique | Palme | Principal = plain cabinet, Palme = twelve sympathetic strings, Métallique = a gong as the speaker cone. |
| Mix | 0 … 1 | 0.5 | How much of the cabinet is mixed with the direct sound. |
| Ring | 0 … 1 | 0.5 | How long the Palme strings or the gong ring on. |
| Tune | -12 … 12 semi | 0 | Retunes the twelve Palme strings, in semitones from C3. |
| Gong | 60 … 600 Hz | 196 | Fundamental of the gong in Métallique, 60–600 Hz. |
| Level | 0 … 2 | 1 | Output level. |
Ports
| Port | Direction | Signal | What it carries |
|---|---|---|---|
| In | in | audio | Audio input: the voices, or anything else. |
| Mix+ | in | cv | Added to the Mix knob. |
| Out | out | audio | The sound through the chosen loudspeaker (mono). |
How it works
All three types first take a little bass and treble off, like a cabinet. The Palme strings are twelve comb filters with damping in the loop, tuned chromatically from C3 (130.8 Hz) and interpolated so they sit exactly on pitch. Tune shifts them in semitones; Ring sets how long they ring, from about 0.8 s to 7.8 s.
The gong is eight band-pass filters on the frequency ratios of a gong, built on the Gong frequency, plus the bright, hard sound of the plate itself. Mix blends the cabinet with the direct sound (Principal has no blend) and a soft limiter guards the output. It is our own model, tuned by ear; no circuit simulation.
Runs on
- Teensy 4.1 (the MusicBrain Brain): about 4.8 % CPU per instance (one note, default settings), measured on firmware 0.5.108.
- The browser: the editor's simulator runs the same C++ code as WebAssembly, so what you hear while patching is what the Brain plays.
Try it
In the editor's example set: 🎐 Ondes ×4 (Martenot-ensemble), 🌊 Martenot + Palme, 🌊 Martenot + Métallique, 🎐 Ondes Martenot, 🎐 Ondes ×4.
Editor: https://editor.musicbrain.nl
Sources & licences
- Modelled on descriptions of the Ondes Martenot diffuseurs (Principal, Palme, Métallique); no third-party code.
- Own kernel
mmb_dsp/diffuseur.h, MIT licence.
Versions
- 0.5.97: Palme strings tuned exactly (C3 now 130.79 Hz); the feedback follows the real damping in the loop, so the after-ring no longer sits at the ceiling.
- 0.5.96: first version, together with the ARP and MARTENOT modules.