SFS Audio · Waterline · in your browser
A MIDI instrument where the water makes the sound: each key drops a drop, and you hear its click and the ring of the bubble it traps, pitched to your note. Everything here changes both what you see and what you hear.
The browser version of Waterline 0.1.1. It plays at 112 BPM, where the plugin follows your DAW's tempo.
| You see | You hear |
|---|---|
| A drop hitting the surface | A short click, brighter the faster it lands (Height) and the tighter the surface (Tension) |
| The note you play | A ring at your note: the air each drop traps rings like a real bubble (the Minnaert frequency), so low notes ring deep and high notes plink |
| Crown beads and the jet's drop landing | Softer plinks an octave or two up. Splash sets how many and how loud, from none (only the first hit) to a big spray; Splash time sets when they land |
| The sky | The weather at the root, ahead of the liquid, the microphones, the echo and the swell. Its noise bed plays under everything, and Cover sets how hard it shapes each drop as it is made: mist softens the attack, overcast darkens and weighs it down, wind bends the pitch and blows the drops and stream sideways, a thunderhead drives it hot, sleet crushes it |
| Follow | Static: the weather's noise plays all the time. Turned up, it follows your playing: it opens when you play and closes the Follow time after your last key lets go, and the clouds thicken and brighten while it is open |
| A stream pouring in | One continuous voice at the key you hold; its ring flutters as the pour churns the surface. Flow sets how thick and loud it runs. Glide slides the stream to the next key you hold, and the pitch slides with it; you hear the note where the stream lands, so the bend in the column is the glide you hear next |
| The liquid | Water rises and sings; oil is soft and dark; honey gloops and blups; milk is muffled; quicksilver rings like metal |
| Thickness | Slower, lazier waves; shorter, duller rings |
| Density | Bigger splashes; more body in the impact |
| The swell rolling through | Chorus or phaser. Where the swell crosses the microphone (the diamond at the centre) is where the effect is right now: Rate is how fast the swell travels, Depth how tall it stands. In Chorus the two faint waterlines are the two delayed copies drifting apart and back; in Phaser the same lines pinch shut at the notches (low on the left, high on the right) and the pinch points slide as the swell sweeps |
| The camera going under | The microphone going under |
| Ripples bouncing off the basin walls | The echo |
TryPlay a slow low note, then a high one: a deep ring, then a bright plink. Hold a chord in Shower. Switch to Honey and play the same thing. Drag Listening under the water while you hold notes in Storm. Load "PD Oil Haze" and watch the notches slide along the surface.
Reject ifyou can't tell the liquids apart with your eyes closed, or what you see doesn't predict what you hear.
Honest labelThe sound is made from the scene: every impact on screen triggers its own sound, sized by the drop. Splashes unfold slower than life so you can see them; the secondary plinks follow the picture, not real time. Height adds a real fall before you hear a drop.
Researchdocs/waterline-research-2026-09-29.md in the SFS Audio repo.