Modal tuning
Modal tuning, is a technique that allows to “tune” the vibration modes of the instrument. It consists in the application of a scientific method to analyse the vibration modes and, if needed, tune them by modifying their mass and stiffness. Although this methid is known since a long time in engineering, it is seldom applied in lutherie. The pioneer in its application is Australian luthier Trevor Gore. I had the opportunity to attend his course in guitard design and modal tuning in 2019 and now this technique is routinely applied on the instruments I make.
Modal tuning is performed both during the design phase, when the soundboard thickness and bracing are determined, and once the instrument is almost ready, in order to optimize the sound for each single note, avoiding undesired coupling phenomena between strings and instrument that often induce tuning errors or wolf notes that in pucked instruments mean “dull” notes with low volume.