Modal analysis of a violin octet.

Experimental modal analysis of a complete Hutchins-Schelleng violin octet, combined with cavity mode analysis and room-averaged acoustic analysis, gives a highly detailed characterization of the dynamics for this historic group of instruments. All the "signature" modes in the open string pitch region--cavity modes A0 ("main air") and A1 (lowest longitudinal), C-bout "rhomboid," the first corpus bending modes B1- and B1+ (comprising the "main wood")--were observed across the octet. A0 was always the lowest dominant radiator, below all corpus modes. A1 contributed significant acoustic output only for larger instruments, but was the dominant contributor for the large bass in the "main wood" region. Acoustic results indicate either B1- or B1+ can be the major radiator. Damping results indicate that B1 modes overall radiate approximately 28% of their vibrational energy. "Doublet" B1 modes from substructure couplings were observed for three instruments. "A0-B0" coupling was not significant for the largest instruments. The original flat-plate-based scaling of the "main wood" resonance was generally successful across the octet, although that for the "main air" was not.