The differences between a xylophone and marimba relate to the range of the instruments, their pitches, the mallets used with them, and their resonators. Both instruments are percussive and use beaters to strike wooden keys, but their specific qualities differ. The marimba can also produce lower notes than the xylophone. Xylophone notes also sound out at a higher pitch than they are written in musical notation. Resonators are used to amplify the sound on both the xylophone and marimba, but the marimba’s resonators are longer.
The ranges of the xylophone and marimba are one factor which differentiates them. Range is indicated by the number of octaves an instrument can play. An octave is a full run of twelve notes, from A to G sharp. Xylophones have a range of two-and-a-half to four octaves. Marimbas have a larger range, usually between three and five octaves.
The actual pitch produced by the instrument, compared to the pitch written in musical notation, can also be used to differentiate a xylophone and marimba. Xylophones produce notes one octave higher than the written pitch. For example, a middle C (C4), which is found one line below the treble clef staff, will actually become a high C (C5) when played on a xylophone. Marimbas produce the notes as they are written. The lowest note on a xylophone is middle C, but marimbas can have notes up to two octaves lower.
Different mallets are used with xylophones and marimbas. Both use wooden core mallets, but those used on a xylophone are wrapped in a harder material. This is usually a rubber or plastic, which gives the instrument its high, biting tone. Marimba mallets are coated in cord or yarn to provide a more mellow tone when the instrument is struck. The specific cutting style used on the keys also contributes to the tone's brightness or mellowness.
The resonators used to amplify the sound have different lengths on the xylophone and marimba. Resonators are metallic tubes which extend from the bottom of the keys down towards the ground. The larger keys on the xylophone have larger resonators, meaning that the resonators decrease in length according to the key size. Both the largest and smallest keys on a marimba have long resonators, creating an arch of long tubes beneath the instrument. The smallest resonators on a marimba are comparable in size to the longest ones on a xylophone.
The xylophone and marimba are often used in different musical circumstances. Xylophones are more commonly found in symphony orchestras and concert bands. Marimbas, conversely, are occasionally used alone and often found in much smaller musical ensembles.