Vibrations picked up by a piezo element are analyzed by an algorithm controlling an oscillator. The oscillator is output via a speaker which in turn sets the spring in motion. With direct control over parameters like the oscillator range and delay time the seemingly unstable feedback can be guided to specific frequencies and sounds.
The instrument is played by physically interacting with the spring, manipulating the toggles controlling signal flow and the faders mapped to parameters of the algorithm.
A secondary signal path is sent to external amplification with a processed version of the signal as created by the feedback path. This path adds a contrasting layer to the local and raw sound of the feedback spring. Ideally the secondary signal is spatialized with a multispeaker setup in a large geometric shape around the performer.
Performances played with Pandora’s Box are improvised in nature but follow one principle. Metaphorically Pandora’s Box opens halfway through the performance. At that point the sound is not constrained by the single speaker inside the box and is spatialized in the surrounding space with some form of external speakers.
For me, the key value in improvising is having fun and surprising people with a relatively simple looking instrument.