After spending ten years painstakingly measuring the acoustics of violins rated from 'bad' to 'excellent' by professional musicians, George Bissinger of East Carolina University says that the 'excellent' old Italian violins in his sample show a significantly stronger acoustic response in the lower octaves than do the 'bad' violins, whereas those rated merely 'good' have intermediate values. The high-quality tone is caused by a single mode of vibration of air inside the body, which radiates sound strongly through the violin's f-holes.

Bissinger measured all manner of sound characteristics for the 17 instruments in his sample, which ranged from legendary Stradivari instruments to mass-produced beginners instruments. He focused on the properties of the key vibrational resonances or 'modes' of the instruments, recording the frequencies of these modes, the radiativity, the degree of focusing in specific directions (directivity), the flexibility of the wooden body plates, and the amount of damping of the sound. The two Stradivarius instruments showed respectively the highest and the lowest degrees of directivity in the sample. But crucially, the best violins showed a more even radiation of sound across the range of acoustic frequencies that they generate. In particular, the greater strength of their lowest-octave response can partially account for the richness and sweetness of tone that violinists say they detect.