Sensing Ballistics

Sensing Ballistics: Rethinking Velocity in Piano Design

Our research in piano ballistics has revealed critical flaws in the current digital piano designs, which rely on measuring average key velocity. While this simplified measurement is used to trigger sound samples, it does not accurately represent the complex dynamics of a real piano’s action.

In our experiments, we used the same sensors employed by traditional systems to measure key velocity and compared the results with the actual terminal hammer velocity, which determines for the most part the loudness of the tone on an acoustic piano. The findings were clear: the average key velocity measured by traditional digital pianos has little correlation with the terminal hammer velocity. In fact, even with identical touch, the two velocity values were significantly different.

To address this, we developed software that accurately calculates terminal hammer velocity and other relevant dynamic values. By comparing these to the simplified average velocity used in digital pianos, we found that our system provides values that directly correspond to what would happen on a real piano, while the conventional method provides an oversimplified and inaccurate representation.

This research underscores the need to move beyond velocity-based measurements in digital instruments. Accurate sensing of ballistic behavior is essential for creating instruments that truly reflect the musician's input, this is the core of what the piano playing experience really is about.