In addition to being a novel oscillator source, speaker feedback can be a means of analog/digital signal exploration –
Speaker Synth is a five-speaker array with no external audio input, created by Lesley Flanigan. The only components in the system are the instrument’s speakers, piezoelectric microphones, amplifying circuits, and the hands of the performer. Speaker Synth is played by positioning individual piezo microphones with their corresponding speakers and manipulating their associated on/off and volume controls to induce a variation of feedback effects. During the performance, samples from both Speaker Synth and a vocalist are captured and sequenced to build a dense sonic pallet of rhythms and melodies.
Speakers are so readily available these days, often discarded while still in perfectly usable condition. Projects like this do well to showcase the simple components’ versatility and value. – Speaker Synth
Here’s a short video where Lesley explains and demonstrates Speaker Synth, shot by Make:Books editor Brian Jepson.