An acoustician’s approach of the solid body electric guitar
Arthur Paté, Jean-Loïc Le Carrou, Benoît Fabre · 2022
The perceived sound of a solid body electric guitar mainly results from the electroacoustic system that radiates the signal of vibrating strings. Most of the previous works in acoustics and audio signal processing focused on amplifiers, effect pedals, pickups, etc. However, sound originates from the vibration of strings indeed. This presentation demonstrates that the sound of the electric guitar is determined by its mechanical manufacturing quality, even if it is electroacoustic. By mechanical coupling, the vibration properties of the structure determined by elements of stringed instrument manufacture (wood, geometry, etc.) influence the vibration of strings and, consequently, the resulting sound. An initial body of guitars (relevant regarding organological, economical and musicological viewpoints) was studied by mechanical (vibration analysis) and perceptive approaches (linguistic analysis of conversations during playing situations). This body contains one stringed instrument manufacture element that was intentionally made variant. Results enable to explain certain sonic differences and show that musicians are capable of identifying the variation in this manufacture element. By observing that guitars purposely made identical can present differing characteristics, it is possible to focus on the manufacturing process itself. Thus, two additional bodies were used to study the vibration behavior during construction and the inter-instrument variability at the last stage of industrial production, which indicates the know-how of stringed instrument makers, in order to minimize variability and the importance of the choice of material. Finally, we will discuss how the electric guitar’s manufacture elements can contribute to the sound of the instrument: musicians are sensitive to the latter, and some vibration descriptors become aware of it.