How a Marimba is Made
Tuning the tone plates

Tuning the tone plates is one of the most crucial processes during the wider process of manufacturing a marimba. With a marimba, the undersides of the tone plates are sanded down, matching higher notes to lower notes. It is all over if the pieces are sanded down too much and the notes are lower than prescribed. There are no do-overs. Each piece of wood has considerable variations. With rosewood, for instance, less intense color means a higher note, while deeper coloring means a lower note. Adjustments must also be made based on the grain. Because the shape and amount sanded off will differ, a sander is used on the tone plate, and then the sound is checked periodically with a tuner throughout the tuning process.

Sanding a tone plate by pressing a tone plate into a revolving sander

Sanding a tone plate by pressing a tone plate into a revolving sander

Matching sounds with a tuner

Matching sounds with a tuner

The tuning of a tone plate is performed carefully while checking both the fundamental tone and the harmonics. Using a mallet, the fundamental tone can be checked by striking the center, and the fourth harmonic can be checked by striking around 1/4 the way from the end. If the note differs horizontally across the tone plate, then the note will not sound clean. Thus, adjustments are made based on the degree of sanding in this respect, as well.

During the first stage, the tone plates are only tuned to roughly match the ideal before the wood is left to rest for around a month. Because sanding is hard on the wood, it is left to rest in peace, the craftsman waiting for the sound to take shape.

The undersides of sanded tone-plate materials have various shapes

The undersides of sanded tone-plate materials have various shapes