Spruce soundboards with the highest sound-transmission coefficient For soundboards, Young Chang uses A-class northern spruce, which provides an excellent sound-transmission coefficient. Young Chang’s ingenious soundboard design includes a low-note portion shaped like a round speaker with creases, optimizing the efficiency of vibration and effect of resonance and creating a deep, rich tone. Precise action that expresses the pianist's emotion more delicately The three factors of beautiful sound in a piano – volume, tone and quality – depend on the precise action of the sound-producing mechanism of a piano. The action of a Young Chang piano, consists of 4,500 parts, each manufactured with an error tolerance of 5/100mm, and made of hard maple to resist deformation from excessive use. A keyboard that conveys the soul of the pianist Young Chang keyboards are made of wood with lower specific gravity but higher elasticity, giving the pianist a softer yet firm sense of touch.