Are phantom partials produced in piano strings?
Thomas R. Moore, Lauren M. Neldner, Eric Rokni · The Journal of the Acoustical Society of America · 2018
The anomalous frequency components in the sound from a piano, often referred to as phantom partials, were first noted almost 75 years ago. They occur at the sums and differences of the frequencies generated by the transverse motion of the string, and it is generally accepted that they are produced by longitudinal motion of the string that is associated with the normal transverse motion. Experimental evidence will be presented demonstrating that while some of the power in a phantom partial may originate in the string, most of it does not. A simple theory explaining how phantom partials may originate in the wooden components of the piano will be presented.