Collision: Design the Strike and the Ring Separately

One note starts a small resonant system

Collision is an instrument, not an effect waiting for incoming audio. Each MIDI note triggers an internal strike and a bank of resonant modes. The played pitch and Tune establish the fundamental; Resonator selects the relative frequencies above it. The example uses an original MIDI melody and hand-authored Marimba settings, without recorded mallet samples.

The model is a filtered impulse, optional filtered noise and a bank of two-pole resonators. Body names describe the chosen modal relationships, not a fully simulated object with every physical detail. There is no second resonator-routing section in this panel. Learn the behavior present here rather than importing expectations from another instrument with a similar name.

Listen at three points in the note

At the instant of contact: Stiffness

Reduce Stiffness from 65% toward 20%. A softer, more filtered strike excites less high-frequency energy. Restore it and listen to the attack becoming more pointed. Compare new notes after each change, since the strike is a note-on event, not a continuously running oscillator.

Just after contact: Bright

Bright tilts the amplitudes of the resonant modes. Compare the initial 0.2 with a negative value while leaving Stiffness alone. You are changing the balance of the body's partials, not simply making the mallet softer. Back off if high modes distract from recognizing the melody.

Later in the tail: Material

Material changes the relative decay of higher modes. Negative values damp them faster; positive values let them persist longer. Compare -0.35 with +0.35. Ask whether brightness survives into the tail, not only whether the next attack feels louder.

Decay supplies the fundamental ring time in seconds. Increasing it does not turn the MIDI phrase into longer written notes; it changes how long the resonant energy lasts. Keep Decay short enough that neighboring notes remain distinguishable when the melody moves quickly.

Choose the body before fine-tuning its balance

Compare Marimba with String and Plate, keeping Tune at zero. String uses harmonically related modes, whereas Plate uses irregular ratios. The apparent pitch can become less straightforward as nonharmonic partials grow more prominent. A fixed fundamental does not mean that every body will blend equally well with the same chord.

Position changes the weighting of modes using a striking-position pattern. Move it away from the initial 29% toward the center, 50%, and listen for selected partials weakening. It is neither stereo pan nor a second tuning control. Find a useful balance with Position before trying to solve every tonal issue by making Bright darker.

Decide what note length should mean

Gate starts at Ring. In this mode the scheduled note ending does not apply the fast note-off damper, so a short MIDI note can leave a longer tail. Switch Gate to Gated and compare the ends of the visible notes with the sound. This is useful for tight rhythmic articulation, but it can make a long Decay setting seem ineffective if notes are cut off early.

Finally add a little Noise. Color is its lowpass frequency and N Decay its duration in milliseconds; these do not replace the resonator's Decay. Noise can add a rougher onset, but too much sustained noise can obscure the tuned body you just balanced. Return Noise to zero if you cannot tell whether a change belongs to excitation or resonance. Set Volume after those comparisons, rather than rewarding the loudest configuration.