Professionals consider the differences in the timbre of bass tones between large grand pianos and small uprights as significant. By tradition this difference has been attributed mainly to lower inharmonicity in grand pianos, due to longer bass strings. In this study, the importance of the spectral envelope, representing the dynamic balance between high-frequency and low-frequency energy in the spectrum, is contrasted against the importance of the level of inharmonicity. Results from two listening tests indicate that the inharmonicity is less important than the spectrum bandwidth in determining the timbre of piano bass tones.
Galembo, Alexandre; Askenfelt, Anders; Cuddy, Lola L.; and Russo, Frank A., "Perceptual significance of inharmonicity and spectral envelope in the piano bass range" (2004). Psychology Publications and Research. Paper 6.