In most cases, a soundboard crack does not harm piano tone. Buzzes and rattles can enter the picture when the ribs glued to the back of the soundboard become loose.

Soundboard design is extremely complex. A good soundboard will have “crown” similar in concept to the arched top of a violin. The downbearing of the strings across the bridges is substantial so in many (most!) old pianos the crown has collapsed and with the disappearance of crown the piano’s singing tone and ability to sustain a tone has also disappeared. As with worn hammers and action parts, it is appropriate to replace a defective soundboard in the course of a restoration project.