Material Properties and the Modes of Vibration of Piano Soundboard

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The soundboard of the modern piano is a thin plate made in resonance spruce of about 7-9.5 mm thickness that underpins the strings and the cast iron plate and rests on the rim braces. The ribs support the soundboard on the underside and on the opposite side the soundboard has two bridges over which the strings are stretched. The soundboard is made from timber strips of about 12 cm wide which are glued to form a big panel which is trimmed to grand piano or upright piano size. Concert grand pianos and other high quality pianos have the soundboard made in high quality resonance spruce. Each soundboard's mode of vibration has its particular radiation pattern, depending mainly on the geometry of the soundboard and on material, physical and mechanical characteristics. The action mechanism is of high mechanical complexity and can greatly influence piano sound quality as well as the player's touch. Piano hammers are constitutive elements of the piano mechanism and have a considerable contribution to piano timbre. The modern piano keyboard contains 88 keys for playing the twelve notes of the Western musical scale, repeated at the interval of an octave and laid out with the lowest note on the left of the keyboard. The white keys are made in spruce, white pine or other softwood, covered with ivory for high quality pianos or with high quality plastic (pyralin, elforyn) or made entirely from white plastics for low quality instruments. Black keys are in ebony or in black plastic material. The rim of the case of the piano is made using the traditional technology employed in making fine furniture.