Bars Marimba bars may be made either of wood or a synthetic
fiberglass material. For the best sound quality,
rosewood is the most desirable, while
padauk is a popular affordable alternative. Synthetic fiberglass bars are often sold under trade names such as Kelon (for
Ludwig-Musser), Klyperon (for
J.C. Deagan), or Acoustalon (for
Yamaha), among others. Bars made from synthetic materials generally fall short in sound quality and generally have a longer decay in comparison to wooden bars, but they are often less expensive and yield added durability and weather resistance, making them suitable for outdoor use. For wooden bars, changes in humidity or temperature may alter the moisture levels within the wood. This may negatively affect the pitch and tonality of the bar.
Bubinga (
Guibourtia demeusei) and
mahogany have also been cited as comparable to rosewood in quality for use as marimba bars. The specific rosewood,
Dalbergia stevensonii, only grows in Southern Guatemala and Belize, formerly British Honduras. This wood has a
Janka rating of 2200, which is about three times harder than
silver maple. The bars are wider and longer at the lowest-pitched notes, and gradually get narrower and shorter as the notes get higher. During the tuning, wood is taken from the middle underside of the bar to lower the pitch. Because of this, the bars are also thinner in the lowest pitch register and thicker in the highest pitch register. While most American marimbas are tuned to the standard A4=440 Hz, many commercial marimbas are tuned to A4=442 Hz for a brighter sound for better blend with an orchestra. Marimba bars produce their fullest sound when struck just off center, while striking the bar in the center produces a more articulate tone. On chromatic marimbas, the accidentals can also be played on the extreme front edge of the bar, away from the
node (the place where the string goes through the bar) if necessary. Playing on the node produces a sonically weak tone, and the technique is only used when the player or composer is looking for a muted sound from the instrument.
Range There is no standard range of the marimba, but the most common ranges are 4.3 octaves, 4.5 octaves and 5 octaves; 4, 4.6 and 5.5 octave sizes are also available. • 4 octave: C3 to C7. • 4.3 octave: A2 to C7. The .3 refers to three semitones below the 4 octave instrument. This is the most common range. • 4.5 octave: F2 to C7. The .5 means "half"; • 4.6 octave: E2 to C7, one semitone below the 4.5. Useful for playing guitar literature and transcriptions. • 5 octave: C2 to C7, one full octave below the 4 octave instrument, useful for playing cello transcriptions, e.g.,
J. S. Bach's cello suites. • Bass range (varies, but examples range from G1–G3 or C2–F3) The range of the marimba has been gradually expanding, with companies like Marimba One adding notes up to F above the normal high C (C7) on their 5.5 octave instrument and marimba tuners adding notes lower than the low C on the 5 octave C2. Adding lower notes is somewhat impractical; as the bars become bigger and the resonators become longer, the instrument must be taller and the mallets must be softer in order to produce a tone rather than just a percussive attack. Adding higher notes is also impractical because the hardness of the mallets required to produce the characteristic tone of a marimba are much too hard to play with in almost any other, lower range on the instrument. The marimba is a non-transposing instrument with no octave displacement, unlike the
xylophone, which sounds one octave higher than written, and the
glockenspiel, which sounds two octaves higher than written.
Resonators Part of the key to the marimba's rich sound are its
resonators. These are tubes (usually
aluminum) that hang below each bar. In the most traditional versions, various sizes of natural
gourds are attached below the keys to act as resonators; in more sophisticated versions carved wooden resonators are substituted, allowing for more precise tuning of pitch. In Central America and Mexico, a hole is often carved into the bottom of each resonator and then covered with a delicate membrane taken from the intestine of a pig to add a characteristic "buzzing" or "rattling" sound known as
charleo. In more contemporary-style marimbas, wood is replaced by
PVC tubing. The holes in the bottoms of the tubes are covered with a thin layer of paper to produce the buzzing noise. The length of the resonators varies according to the frequency that the bar produces. Vibrations from the bars resonate as they pass through the tubes, which amplify the tone in a manner very similar to the way in which the body of a guitar or cello would. In instruments exceeding octaves, the length of tubing required for the
bass notes exceeds the height of the instrument. Some manufacturers, such as
DeMorrow and
Malletech, compensate for this by bending the ends of the tubes. This involves soldering smaller straight sections of tubes to form "curved" tubes. Both DeMorrow and Malletech use brass rather than aluminium. Others, such as
Adams and
Yamaha, expand the tubes into large box-shaped bottoms, resulting in the necessary amount of resonating space without having to extend the tubes. This result is achieved by the custom manufacturer Marimba One by widening the resonators into an oval shape, with the lowest ones reaching nearly a foot in width, and doubling the tube up inside the lowest resonators—a process known as
"Haskelling", originally used in pipe organ resonators, and named for its inventor,
William E. Haskell. Resonator tuning involves adjusting "stops" in the tubes themselves to compensate for temperature and humidity conditions in the room where the instrument is stored. Some companies offer adjustment in the upper octaves only. Others do not have any adjustable stops. Still some companies (Malletech and DeMorrow) offer full-range adjustable stops. On many marimbas, decorative resonators are added to fill the gaps in the accidental resonator bank. In addition to this, the resonator lengths are sometimes altered to form a decorative arch, such as in the Musser M-250. This does not affect the resonant properties, because the end plugs in the resonators are still placed at their respective lengths.
Mallets The mallet shaft is commonly made of wood, usually
birch or rattan, but may also be made of
fiberglass or carbon fibre. The most common diameter of the shaft is around . Shafts made of rattan have a certain elasticity to them, while birch has almost no give. Professionals use both depending on their preferences, whether they are playing with two mallets or more, and which grip they use if they are using a four-mallet grip. Appropriate mallets for the instrument depend on the range. The material at the end of the shaft is almost always a type of rubber, usually wrapped with yarn. Softer mallets are used at the lowest notes, and harder mallets are used at the highest notes. Mallets that are too hard will damage the instrument, and mallets that might be appropriate for the upper range could damage the notes in the lower range (especially on a
padouk or
rosewood instrument). On the lower notes, the bars are larger, and require a softer mallet to bring out a strong fundamental. Because of the need to use varying hardnesses of mallets, some players, when playing with four or more mallets, might use graduated mallets to match the bars that they are playing (softer on the left, harder on the right). Some mallets, called "two-toned" or "multi-tonal", have a hard core, loosely wrapped with yarn. These are designed to sound articulate when playing at a loud dynamic, and broader at the quieter dynamics. == Mallet technique ==