Free Plate Tuning, Part Two: Violins

by Alan Carruth

Originally published in American Lutherie #29, 1992 and Big Red Book of American Lutherie Volume Three, 2004

See also,
Free Plate Tuning, Part One: Theory by Alan Carruth
Free Plate Tuning, Part Three: Guitars by Alan Carruth



Before I get into plate tuning proper I’d like to digress a bit and discuss the rationale behind the process, and a couple of other things I find it useful to keep in mind while I’m working. And I can’t think of a better way to begin than by telling you about one of my more elaborate experiments.

Fig. 15 gives the relevant information on my fourth and fifth violins. The idea was to check out the influence of asymmetric back graduations by building a pair of closely-matched fiddles with that as the only variable. The one-piece backs were cut from the same plank of bird’s-eye maple and the tops were cut from a red spruce 4×6 that I took out of the wall of my house when I put in a new chimney. The molds were routed using a template. Archings were checked for height at over two dozen points on each plate and were held to .2MM. Graduation, weight, and frequency data is as shown. The delta f mentioned is the frequency drop obtained when a 5G weight was stuck to the plate in an active area of the given mode. Fittings and so on were matched as closely as possible, and the two bridges were cut back to back from the same piece of maple.