Changing the FM modulator waveform (square, sine, sawtooth) shifts the Reese's harmonic character

In an FM Reese patch, the modulating operator’s waveform shapes the character of the resulting movement and harmonic spectrum. A soft square modulator produces a warmer, rounder wobble. A sine produces a cleaner, less harmonically complex modulation. A sawtooth or parabola produces a harsher, buzzier character. Inverting the modulator waveform changes the phase relationship, altering the specific tonal output (can add or remove bass weight). Experimenting with modulator waveform is a sound-design tool: different waveform choices produce recognizably different flavors of Reese, even with identical carrier and ratio settings. This is distinct from changing the carrier waveform (which affects the raw tone) vs the modulator waveform (which affects the modulation shape).

Examples

In FM8: operator D (modulator) set to soft square — warm wobble. Switch to sine — cleaner, smoother modulation. Invert the modulator waveform — different bass weight and harmonic shift. These are all variations on the same patch.

Assessment

Explain the difference between changing the carrier waveform and changing the modulator waveform in an FM Reese patch; then predict what happens to the sound when the modulator is inverted.