On the Dynamics of the Harpsichord and its Synthesis

Henri Penttinen
DAFx-2006 - Montreal
It is common knowledge that the piano was developed to produce a keyboard instrument with a larger dynamic range and higher sound radiation level than the harpsichord possesses. Also, the harpsichord is a plucked string instrument with a very controlled mechanism to excite the string. For these reasons it is often falsely understood that the harpsichord does not exhibit any dynamic variation. On the contrary, the signal analysis and the listening test made in the this study show that minor but audible differences in the dynamic levels exist. The signal analysis portrays that stronger playing forces produce higher levels in harmonics. The energy given by the player is not only distributed to the plucking mechanism but also carried on from the key to the body. This is evident from the increased level of body mode radiation. A synthesis model for approximating the dynamic behavior of the harpsichord is also proposed. It contains gain and timbre control, and a parallel filter structure to simulate the soundboard knock characteristic for high key velocity tones.