Technical Dulcimer by Sam Rizzetta
Strings #5 Bass bridge parallel to right side bridge
n the last issue we used the plain string equations to design a twelve treble course hammer dulcimer with string scale lengths that would meet certain requirements. These included tone, sustain, tuning ease, and portable size. Figure 1 is a drawing of our hypothetical du lcimer with string lengths and the dulcimer dimensions that relate to string lengths. Our target was a maximum scale length of 65 % breaking strength for the highest pitches and an overall dulcimer frame length of forty inches or less. Our task this issue is to design the bass course scale lengths. To do this we must make two decisions: where to place the bass bridge and how to tune the bass courses. Many du lcimers from earlier times had no bass courses at all. Early dulcimers that have bass usually have the bass bridge placed close to the right side bridge and parallel to it; see Figure 2. This makes for re latively long strings and requires fewer gauges of wire. Such dulcimers usually used the same steel or iron wire for both treble and bass. However, the low strings requ ire a long reach to play, and the bridge vibrates the soundboard close to the right side, which responds poorly to the low notes. The tone is not all it could be. For playing ease the best placement of the bass bridge would be parallel to the treble bridge; see Figure 3. Here the low notes would vibrate a responsive area of the soundboard, but the string scale lengths
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Bass bridge parallel to treble bridge
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Bass bridge compromise location
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Dulcimer dimensions and treble course scale lengths Please do not reprint or redistribute without permission. Contact dpn@dpnews.com.
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