The nominal purpose of scalloping is to remove wood in a way that loosens the top in a way increases amplitude mostly in the bass range, or so I’ve read in articles by people who know more than I do. My experience (and I acknowledge that anecdote != data) accords with that. I tend to find scalloped-braced instruments a bit outsized in the bass, and that’s playing finger type with a bare thumb (no pick). Thumpy bass is useful for some players, but in general, I’m not one of them.
By contrast, the straight-braced instruments (mostly Martins) from the late 40s through the 70s tend to sound better for strumming with a pick. My working hypothesis involves the additional stiffness imparted to the top by larger, mostly uncarved bracing helping to even out the peaks and valleys of sound and requiring more energy per dB to drive the top, possibly resulting in some effects which mimic electronic compression. The bass is relatively tight and the dynamic range is reduced, or at least they feel that way to present deponent.
Tapered has a bit more bass than straight-braced instruments and less than scalloped, IME. It seems a good bit more even in terms of volume throughout the compass of the instrument, with nice trebles and a solid but not thumpy bass. It seems that the purpose of the tapered shape has to do with loosening the top in a way that is qualitatively different from scalloped; it should change the way the Chladni (vibration/glitter) patterns present bc the location of the vibrating nodes and antinodes on the top change quite a lot. I suspect that it elides some of the strong nodes seen in scalloped x bracing and makes the frequency response of each vibrational mode a little wider.
I’ve played instruments that refute this in one way or another, but it’s a rule of thumb that has at least a germ of truth, alt least for what I play (fingerstyle, complex chords, etc). Fortunately, Richard has access to and ongoing interest in the science of guitar acoustics, and consequently can talk much more knowledgeably and with greater confidence about specific frequency response curves imparted by different bracing patterns.
For me? Small, shallow body, tapered bracing, long scale, big neck, wide string spacing; in general tghose attributes, in my experience, will get me most of the way to what i want. As always, usual disclaimers apply: YMMV, anecdote != data, IANAL, et cetera.
- This reply was modified 1 year, 5 months ago by Matt Hayden.