Rumbler: A Reverb-Based Feedback Instrument

Tae Kyu Kim

Rumbler: A Reverb-Based Feedback Instrument
Image credit: Tae Kyu Kim

Abstract:

We present the Rumbler, a feedback instrument that harnesses acoustic reverberation to generate complex, unpredictable sounds. A microphone and speaker are mounted to opposite ends of a tube. As the tube is stretched and compressed, the acoustic space within it changes, amplifying different resonant frequencies and altering the resulting pitch. The Rumbler also features four force-sensing resistors, a mouse scroll wheel, and a 9DOF sensor, which can be mapped to various audio filters. These controls modify the audio feedback, enhancing the instrument’s expressiveness and sonic complexity.

We discuss strategies and considerations for mapping filters for the Rumbler and detail two particular mappings that were used for live performance. We share our reflections on the success and limitations of these mappings. Finally, given that the Rumbler can sustain sound without any audio input, we explore the connection between the Rumbler and no-input mixing and its implication for future practice and performance.