Acoustics: Sound Fields, Transducers and Vibration, 2nd Edition

6.10. Measurement of Thiele–Small parameters

Before embarking on a loudspeaker enclosure design, we need to know the six Thiele–Small parameters that will be used to calculate the low-frequency response of our chosen drive unit in the enclosure. Most drive unit manufacturers now provide these on their data sheets, but if they are not available, we have to measure them. Even if they are available, production tolerances are such that we cannot always expect our computed frequency response to match the measured one unless the model used for computation is based on parameters obtained from the measured sample. In this section, it is shown how to obtain the Thiele–Small parameters purely by measuring the electrical input voltage at different frequencies ...