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How Sensory Percussion Works

This page is the map for the rest of the manual: how a hit becomes sound, and how the pieces fit together. To start playing first, see Software First Steps.

From hit to sound​

From hit to sound: the drum and sensor feed a hardware input, where an ML model recognizes the zone. The hit is matched by name to a virtual input, every layer whose input filter matches plays, the layers are mixed, and the result goes out through a hardware output to your speakers. From hit to sound: the drum and sensor feed a hardware input, where an ML model recognizes the zone. The hit is matched by name to a virtual input, every layer whose input filter matches plays, the layers are mixed, and the result goes out through a hardware output to your speakers.

Two things make this work:

  • Inputs are matched by name. Your hardware input Snare 1 feeds the virtual input Snare 1, and sets are written for virtual inputs, not for your particular drums. That's why a set from the library plays on your kit.
  • One hit can play many layers. Every layer whose input filter matches, like Snare 1 or All Snares, plays, each with its own sounds, effects, and fader.

What the sensor hears​

A conventional trigger tells the computer when you hit and how hard. The Sensory Percussion sensor also hears where and how: every hit carries its zone, which can be a place on the drum like the center or edge, or a gesture like a rimshot, a stickshot, or hitting the rim with the shoulder of the stick, its velocity, its timbre (a smooth scale between zones, like how far from center toward the edge), and its speed (how close together your hits are).

A machine-learning model listens to each hit and recognizes which zone it came from. On drums, the hits you play when you train teach the model your drum and your playing, so a few minutes of good training make everything else work better. Cymbals and hi-hats use a model that's fully pre-trained, so there's nothing to train.

Your setup and your music are separate​

The diagram's colors mark the two halves. Your setup (your audio interface, hardware inputs and outputs, MIDI, and OSC) is the same whichever session is open, and is saved in an environment. Your music (sessions, sets, and sounds) is the same whichever setup you plug into, and is saved in a session. So a session built at home plays on stage, and you can switch setups without touching your sessions.

How a session is organized​

How a session is organized: a session holds sets; a set holds layers; and each layer holds a tree of modules, like a Drum Pads controller containing a Note Controller with a Sampler inside it on the center pad, and a Sampler with a Reverb effect on the edge pad. How a session is organized: a session holds sets; a set holds layers; and each layer holds a tree of modules, like a Drum Pads controller containing a Note Controller with a Sampler inside it on the center pad, and a Sampler with a Reverb effect on the edge pad.

What it is
SessionA file (.sp2) holding your sets, like a gig or a project. You work either in the always-saved Workspace or in a saved session.
SetOne sound world, like a song: its layers, macros, and look. You switch sets while you play, and the Global Set is always playing alongside.
LayerOne part, like the drums or the chords: a row in the Edit view and a fader in the Mix view.
ModuleThe building blocks inside a layer. Modules can hold other modules.

Modules​

  • Generators make sound or send messages: samplers, audio inserts, MIDI generators.
  • Controllers decide which of the modules inside them plays, and how. Drum Pads sends each zone to its own module, a Sequencer steps through its modules, and a Note Controller picks a pitch.
  • Effects process the sound of the module they sit on.

Controllers can hold any module, including other controllers, and this nesting is where most of the power comes from. In the diagram, a center hit goes through Drum Pads to its center pad, where a Note Controller picks a pitch from how hard you hit and the Sampler inside it plays at that pitch. An edge hit goes to a different Sampler with a Reverb on it.

Making it respond to your playing​

  • Input filters decide which hits reach a module. Modules inside inherit their parent's filter unless they have their own. See Input Filtering.
  • Assignments let your playing move any control. Right-click almost any knob to assign it to velocity, timbre, speed, the hi-hat pedal, an LFO, or a MIDI controller. Hitting harder can open a filter, or moving toward the edge can add reverb.

Where to go next​

Coming from Sensory Percussion 1?

In version 1, each sound belonged to one drum's channel. In version 2, sounds live in layers that any drum can play, and each layer is mixed on its own. Your setup is saved separately from your sessions.