The Mudcat Café TM
Thread #60344 Message #965630
Posted By: JohnInKansas
11-Jun-03 - 02:35 AM
Thread Name: Building a mountain dulcimer
Subject: RE: Building a mountain dulcimer
McSpadden is a "premier" builder, and makes some pretty flashy instruments; but like most of the other "name" builders, they start at about $350 (US) and go up into rather astronomical prices. If you want to purchase a "ready made" and "almost traditional" instrument, they're a good - but not the only - choice. Good kits are available in the $125+ range, or you can probably do your own for as little as $25 or so if you sacrifice on some of the fancy woods and pretty finishing touches.
For the "scratch" builder, one of the rules that must be observed, is that the fingerboard has to be rigid enough to take all of the string tension without bending. It is the only "structural" piece in a mountain dulcimer. There is no bridge in the normal "acoustic" sense - just a board with a nut on each end (and another nut in the middle to strum it). The problem with getting volume and resonance from a mountain dulcimer is that it is very difficult to couple the vibrations from the string into any part (i.e. the soundbox) that has any freedom to move.
In the typical "modern" construction, the fingerboard is glued down - full length - to the top plate of the box, virtually guaranteeing that nothing will have enough freedom of motion to wiggle the air and produce anything resembling the kind of resonance and "voice" expected for other kinds of stringed instruments. Older, and more traditional, designs frequently left a small gap under the fingerboard, except at one or two "pressure points" so that the sound motions could be transmitted into the plate at central points where the plate is flexible and could produce reasonably good "acoustic flapping" of the top deck. While this kind of construction will never give the sort of "voice" obtainable with a conventional "bridge" as is found on a guitar or fiddle, it can be implemented so as to substantially change the volume and tonal quality of the mountain dulcimer.
IF you use a design that actually allows the top plate to move - and can figure out a way to get the acoustic motion transmitted through the fingerboard into a flexible part of the plate, then the material you use for the box can drastically affect the "voice" of the dulcimer.
A couple of "commercial" builders do put "cosmetic" slots under the fingerboard - but if they understood why traditional builders did so, they wouldn't be using those dense, heavy, dead, "pretty" woods like cherry and walnut for the tops; you'd see the same woods traditionally used for guitar tops - or even better, good old spruce like the fiddles. But "pretty" does sell well - and one might question whether making a "louder, more resonant" dulcimer properly observes the traditions of the instrument.
Regardless of how well the acoustic coupling is worked out, one of the "black art" details that significantly affects the "voice" of a mountain dulcimer is the size of the sound holes. Few "home builders" are likely to do enough experimenting to recognize how critical this is, but an extra hole - or too large a hole - can "kill" the sound from any dulcimer. For the beginner, it's probably safest to stick to what you see on the instruments you copy, and to copy every detail carefully. It is important to know that changing the width or depth of the box by even a small amount can mean you need (or at least would benefit from) fairly significant compensating changes in sound hole size. There are formulas for calculating sound hole(s) size - but there are no exact answers to be obtained from the formulas, since a whole lot of "opinionating" goes into how to use them.
There are a few tricky steps to building any instrument, but most of them are in the "once it's done, you'll know if it's right" category. Copying a good instrument, or following a good plan, will produce a "decent" instrument in most cases, and there's nothing very difficult about building a mountain dulcimer using the commonly available plans.