Lutherie
MAKING MATTERS
Something in the air
Points of interest to violin and bow makers
Steve Sirr and John R. Waddle use CT scans to examine the internal air volume of 20 Cremonese violins, and make a surprising discovery about the soundpost position
FIGURE 2 The area beneath the curve represents the internal air volume for the ‘Betts’ violin. Note the ‘soundpost notch’, which exactly divides the violin’s internal air volume into two equal parts.
Since we performed the first CT scan of a violin in 1987, the non-invasive procedure has become standard practice in the study of bowed stringed instruments. In our previous articles we have used CT scans to examine various instrument properties such as the wood density, mass and volume. Others have written about the possible design of the parts of the instruments, including geometric and proportional systems. Now we turn our attention to air.