I’ve been building two guitars with similar design, but different bracing. Once an instrument is structurally complete (but not varnished) I like to string them up to get an initial idea of their tone. First impressions: Despite their different bracing strategies, they’re both VERY loud and they sound remarkably similar. Their fundamental frequencies rose considerably after gluing on the tops, though they both still have a good solid bass tone. The higher frequencies, however, seemed a bit harsh.
In consultation with their future owners, I decided to thin out the top wood around the lower bout of each guitar. It’s a little disconcerting to take a block plane to the spruce top of a guitar, but it’s all for a good purpose!
We all agreed that this seemed to mellow the high end a bit. I wondered if we were just fooling ourselves, but a frequency analysis confirmed that, especially in the non-scalloped guitar, the upper fundamental frequencies were measurably lower in frequency and amplitude after thinning. The scalloped braced guitar still has lower fundamental frequencies overall, which reflects the fact that the scalloping makes the top less stiff.
Varnishing the bodies and gluing on a permanent bridge will further affect the tone of both guitars, and I’ll do further fine-tuning at that stage, but for now they’re both in a good range for a solid dreadnought tone. Keep tuned for the last chapter of this story!