Nicolai Foss
Are you interested in how your archtop guitar is constructed, but not willing to invest all the time or money that it take to familiarize yourself with Benedetto’s book?
In that case, you may benefit from luthier Fernando Alonso Jaén — who BTW builds extremely nice archtops (check that Jamaica!) — who has penned a brief and accessible precis on archtop construction detail (such as “Young modules” and “anisotropy”). Here is a great explanation of why (most) archtop guitars have f-holes:
F-holes intercept the vibrations across the top, forcing the transmission along it. Thus, vibrations coming from the bridge are quickly distributed over the top, losing their energy quickly. The bass bar contributes even more to this effect, as it is placed along the top. As we can see, everything in the violin top plate, from the material (strong, light and very anisotropic) to the resonance holes and the bass bar, is oriented to dissipate the energy in the strings to avoid sustain.
Conventional guitars have a central hole, and consequently the vibrations along the top stop there. A great part of the vibration energy is transformed in vibrations across the top, much slower to develop, so that sustain is higher.
Jazz guitars were designed to be heard in loud environments, with trumpets and saxes, when electric guitars didn’t exist or were not affordable. It was desirable that the energy in the strings dissipated fast, in order to get the loudest volume. F-hole archtop guitars usually have a very poor sustain in exchange for increased volume. In the 1930s, Gibson mentioned the “cutting power” of its L5; this expresses very precisely the consequences of the new design.