How to Make a Bass Marimba

These wooden marimba bars are strung together with ribbon.

The marimba is a keyboard percussion instrument, similar to the xylophone. Marimbas have wooden notes, known as bars, which the player strikes with mallets to produce sound. The term "bass marimba" is variously used to describe a small instrument with just a few bass notes, or a larger instrument -- such as a five-octave concert marimba -- which includes these low bass notes. A contrabass marimba is a rare instrument with notes lower than the lowest note on a concert five-octave -- a contrabass typically runs from C1 to C2 while the five-octave marimba encompasses C2 to C7. The bass notes of a marimba are relatively fragile as they are large and thin.

Things You'll Need

• Bar material
• Bar cord
• Resonator material
• Frame materials
• Woodworking tools

Instructions

1. Choose the wood to create the marimba bars. The bars of Western concert marimbas are typically made of rosewood, which has a warm, resonant tone and a good degree of sound projection. Other, less expensive materials for marimba bars, include padouk wood, also known as padauk. Kelon is a synthetic material designed for use in marimba bars -- Kelon typically rings longer but has less projection than rosewood.

2. Determine the number of bars you require, and the scale or mode their pitches will produce. The bars of a bass marimba are commonly arranged to form a musical scale. Concert marimbas typically use the chromatic scale -- a chromatic bass marimba with an octave range of C to C would have a total of 13 bars. If you are not playing chromatic music, you could use a major or minor scale, or a musical mode such as the pentatonic or Aeolian mode.

3. Cut each individual bar from the wood or synthetic material you have selected. The lower the pitch of an individual bar, the longer and thinner the bar is. For example, the dimensions of a marimba bar producing the pitch C2 -- the lowest pitch on a concert five-octave marimba -- will have to measure approximately 22 inches by 3 inches, with a thickness of one inch. Different dimensions of wood are often used to make the same pitch.

4. Drill two holes through each bar, parallel to the shortest edges of the bar. Make each hole roughly one quarter of the distance from one short edge to the other.

5. Tune each note to the desired pitch, according to its place in the musical scale. Tuning marimba bars involves cutting an arch shape into the underside of each bar. This is a highly skilled task.

6. Pass bar cord through the drilled holes in the bars, connecting the bars together in scale order. If you are using a chromatic scale, string the natural notes together on one piece of cord, and the sharps and flats together on a second cord.

7. Make or find a resonating chamber for each of your marimba bars. Bass marimbas for concert use typically have resonators made of brass or aluminum. Marimbas in many Latin American traditions use wooden resonators; wood, cardboard or plastic are other options. Folk marimbas often use hollow gourds to provide resonating chambers. Generally, the lower-pitched bars require a larger or longer resonating chamber than the higher-pitched bars.

8. Make a frame to hold the resonators in place, with hook-shaped posts to either side of each resonator. Concert bass marimbas commonly use a frame design akin to a large wheeled trolley. Other options include a trestle-like frame, or a soft tabletop surface without bar cord or posts.

9. Place the strung marimba bars on the frame, and run the bar cord though the posts. Tension the bar cord so that the bars are held over the resonators without touching the resonators or frame when struck. Tie a knot in the tensioned bar cord or cords.

References

• Coe Percussion; 5.0 Octave Practice Marimba delivered personally by Matt Coe to South Carolina; Mat Coe
• Dandemutande; The Art and Craft of Building Marimbas; Stephen Golovnin
• Wood Web.com; Characteristics of Padauk; Gene Wengert
• Marimba One.com: Bars
• La Favre.com: Marimba Bar and Resonator Dimensions for La Favre 5-octave instrument
• Marimba One.com: Frames