No one makes a great instrument time and again without some sort of reference knowledge. Second , some of us are more comfortable putting actual numbers down so that we can refer to them later when we see how an instrument turns out well. Such numbers are also useful when we want to compare our measurements with work done by others. A preliminary goal is to measure the stiffness of the wood for braces, soundboards and backs. The soundboard and its associated bracing are designed to both withstand the torquing force of the bridge brought on by string tensions and also to enhance and alter natural resonant frequencies occurring in the structure.
Soundboards composed of different woods sound different to the trained ear.
These different woods have varying inherent stiffness' as well, both from one species to the next as well as within the same tree. Rather than throw up our collective hands and abandon the whole project as too complicated for mere mortals to comprehend, we simply devise a strategy to measure the properties of each piece of wood to be used. Although this may sound inordinately tedious, it's not, since most of those reading this will make relatively few instruments and time is not as much of an issue to the hobbyist as it is in an industrial setting. Further, once the setup has been created, measurements go quite quickly. It is important to appreciate that by making such measurements, a great deal of uncertainty can be removed from the building process because you will know at least some of the starting point properties of your materials.