Two synthesizers played as one. Every note you play sounds on an FM voice and on an analog-style subtractive voice at the same time, and a single XY pad moves between them.
The idea
FM and subtractive synthesis are good at different things. FM gives glassy attacks, bells and metallic overtones; a filtered analog oscillator gives warm body and a soft, round sustain. Duomutator plays both from the same notes and lets you decide how much of each you hear.
The two voices are layered, not morphed into each other: each renders its own sound and they are mixed at the output. Moving across the pad crossfades their levels at constant loudness; moving up and down changes how strongly both voices speak, from soft to bright and intense.
