It looks like I stopped blogging shortly after COVID began. Rather than catch up on the past two years of history, I’m going to pick up with the present.
I’m back at the bench working on a guitar (#4). I’m treating this was one long experiment in design and data recording. What does it take to get the sound I want? Well, for starters, a concrete reference for “the sound I want” would be helpful! I found and purchased a luthier-built guitar in Santa Cruz that has (to my ear) great tone and unbelievable sustain, so I’m treating that as my current gold standard.
One might think that with a starting point sound (guitar #3), and a model of the target, it might be fairly straightforward to go from here to there. But the sound (“timbre”) of a musical instrument is pretty complicated, both in how we can characterize the qualities of the sound, as well as the physical properties of the instrument that manifest these qualities.
At the moment I’m playing with some of the gross physical properties of the instrument, and experimentally noting how they affect sound quality. I’ve got a batch of relatively inexpensive top woods (“inexpensive” being relative, since I think they were around $50 a top) that I plan on treating in a Goldilocks fashion – shaping one to a target, one past the target, and one not quite to the target. Right now I’m focusing on overall mechanical stiffness in two dimensions, which in turn is affected largely by the thickness of the top as well as the height of the braces (all else being equal). Following a procedure outlined by luthier Robbie O’Brien, I’m going to gradually thickness a top to a certain standard of flexibility, brace it, and trim the braces until it’s back to another level of flexibility.
What that target level ends up being is – at this point – an educated guess. So I’ll make another top that’s thinner/looser, and a third that’s thicker/stiffer. I’m constructing a basic body and neck apparatus to attach these tops to in order to get at least a first approximation of how they would sound on a completed, strung up instrument.
Along the way I’m going to be collecting some data – the stiffness of the original material, thickness measurements across an array of points, as well as some point deflection testing. I don’t yet know which of these measures are going to matter most in producing the timbres of the tops, but I’m a data detective by day and hope I’ll be able to systematically investigate this.
A completely different approach would be how a traditional artist approaches their craft – copy masterworks until you get a sense of how the master pulled it off. I could take careful measurements of my gold standard instrument and try to replicate it exactly (or use published plans from other famous instruments). Kenny Hill of Santa Cruz claims this is how he learned his craft; after building relatable copies of many famous designs, he felt he understood what to modify to get the sound he was after.
Of course, another “free parameter” in this sound chase is the ability of the musician, and right now I’m the one and only customer. I’ve re-started lessons, taking a back-to-basics approach on controlling the quality of my sound. In future blogs I’ll probably reflect on what it’s like to be a music student again.
Meanwhile, I’m glad to be able to stretch my writing muscles again!
The Learning Curve 