Curved small enclosures produce the smoothest acoustic response, ideally spherical

Evidence

Some of Olson’s results are shown in Figure 6.64. His research showed that the shape of an enclosure should be, ideally, curved and small with respect to the wavelengths in use. He also found that the shape with the smoothest response was spherical; see Figure 6.64(b). However, he also showed that non-spherical shapes, such as the truncated pyramid and rect­ angular parallelepiped combination shown in Figure 6.64(c), could also give good performance. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2200