Hammer Dulcimer String Length Calculation By Francis Choate Ó 2009

 1 2 3 4 5 6 7 8 9 10 11 12 13 C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B C C# Db D D# Eb E F F# Gb G G# Ab A A# Bb B Multiplier 0.4839 0.4706 0.4545 0.4444 0.4286 0.4156 0.4000 0.3846 0.3750 0.3571 0.3478 0.3333

A string on a hammer dulcimer passes over two side bridges. The side bridges determine the playable length of the string. The string then passes over one bridge somewhere out over the soundboard between the two side bridges. Passing over this middle bridge produces two playable notes from one stretched string.

To figure the string length of the two notes, choose from the number 1 column (vertical column) the note that you want for the longer part of the string. This will be the lower sounding note of the two. Then go across the row (horizontal) to the higher note that you want. Now look down to the "Multiplier" number under the column. Multiply the whole string length between the side bridges by the "multiplier" number. This gives you the short string length. The long string is the remainder, just subtract.

For example if you had a hammer dulcimer that was 30 inches across (between the side bridges) and you wanted a G note with a higher D note. Look in the number 1 column for G, then go across the row (horizontal) to find D. The D is in column 8. Now go down to the multiplier, 0.4000. Multiply 30 (distance between the side bridges) times 0.4000 which equals 12. The D note would be 12 inches long. The G would be the remainder, 30 minus 12 which equals 18. The bridge would be placed according to these measurements.  Then use an electronic tuner and move the bridge slightly while tuning.

If you have a trapezoid shaped hammer dulcimer, the strings will be different lengths. Calculate the bridge position for the shortest string and the longest string.   The bridge position for the other strings is a straight line between the two calculated points.   Each side bridge must always be a straight line.  Each individual string crossing the same middle bridge must use the same multiplier which gives the same interval or musical distance between the two notes.

Trapezoid shaped hammer dulcimers can be symmetric (isosceles trapezoid) or asymmetric.  The process for finding bridge positions are the same for either one.  Calculate the bridge position for the longest string and the shortest string and the other bridge positions are a straight line between the two.