Hybrid Drum: Iterative Development Toward Standalone Operation and Physical Feedback

Casper Preisler; Dan Overholt

Hybrid Drum: Iterative Development Toward Standalone Operation and Physical Feedback
Image credit: Casper Preisler; Dan Overholt

Abstract:

This paper presents the iterative development of a self-contained hybrid percussion instrument combining acoustic excitation with digital signal processing. Building on a prior frame-drum prototype (Iteration 0 [Preisler and Overholt 2025]) that demonstrated low-latency hybrid augmentation but required an external computer and power supply, this work documents two subsequent design iterations toward a compact, battery-powered, standalone instrument.

Iteration 1 introduces a cajon form factor, Daisy Seed microcontroller, Karplus-Strong synthesis, and a first custom PCB, establishing the core interaction model and eliminating host-computer dependency. Iteration 2 adds full battery-powered standalone operation, a redesigned PCB with dual audio outputs, and an internal actuator that reintroduces digitally processed vibrations into the drum body as a physically grounded feedback loop. Three guiding principles emerge across iterations: standalone operation as a non-negotiable condition for performative viability; simplicity in the control interface; and hardware as a platform for future software exploration. The actuation path is functional but under active development to address feedback control challenges; hardware is further prepared for gyroscope-based sensing.

Exploratory encounters with a professional drummer, a creative technologist, and a child revealed the instrument’s capacity to invite interaction beyond conventional techniques and informed the design decisions shaping Iteration 2. This research contributes to hybrid instrument design at the boundary of physical resonance and electronic transformation, documenting both progress made and challenges that remain.