Designing and evaluating an actively controlled acoustic guitar
Author
Schnabel, Levin
Term
4. Term
Education
Publication year
2025
Submitted on
2025-05-26
Abstract
This thesis explores how to make an acoustic guitar that can shape its own vibrations in real time. The project combines control theory with performer-centered design. Using current-sensing amplifiers and actuators mounted where vibrations are measured (collocated actuation), a feedback system listens to the guitar’s body and applies counter-vibrations to selectively damp specific structural modes (that is, particular resonances of the wooden body). Experiments show clear, measurable reductions in these resonances. To understand the expressive and perceptual effects, two interactive design probes were built that embed audio effects inside the feedback loop. Guitarists tried them and took part in interviews about topics such as sense of control, expressive potential, and how the performer–instrument relationship changes. The studies indicate that, although sensing still imposes limits, the system enables new expressive possibilities and alters some familiar behaviors of the acoustic guitar. The work contributes to New Interfaces for Musical Expression (NIME) by linking technical innovation with embodied musical interaction and pointing toward future directions for augmented acoustic instruments.
Denne afhandling undersøger, hvordan en akustisk guitar kan forme sine egne vibrationer i realtid. Projektet kombinerer reguleringsteknik med udøvercentreret design. Ved hjælp af strømfølsomme forstærkere og aktuatorer monteret dér, hvor vibrationerne måles (kollokeret aktuering), opbygges et feedbacksystem, som lytter til guitarens krop og påfører modvibrationer for selektivt at dæmpe bestemte strukturelle svingningsformer (altså særlige resonanser i træet). Forsøg viser tydelige, målbare reduktioner af disse resonanser. For at forstå de udtryksmæssige og perceptuelle konsekvenser blev der bygget to interaktive designprober, hvor lydeffekter er indlejret i feedbacksløjfen. Guitarister afprøvede dem og deltog i interviews om blandt andet oplevelsen af tæt kontrol, udtryksmæssigt potentiale og hvordan forholdet mellem udøver og instrument ændres. Studierne peger på, at selv om sensing stadig sætter grænser, muliggør systemet nye udtryksmuligheder og ændrer nogle af den akustiske guitars vante adfærd. Arbejdet bidrager til New Interfaces for Musical Expression (NIME) ved at forbinde teknisk innovation med kropslig musikalsk interaktion og pege mod fremtidige retninger for augmentering af akustiske instrumenter.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords