Phase Decomposition for Loudspeaker Analysis
The vibration of an electrodynamic loudspeaker driver causes a resulting sound pressure. For simple pistonic vibration, there is a simple relationship between the vibration and the sound pressure. For complex vibration patterns, however, different parts of the vibrating surface contribute differently to the sound pressure, depending on the position in which the sound pressure is evaluated. A technique is presented which decomposes the total vibration into an in-phase component which contributes positively to the sound pressure, an anti-phase component which contributes negatively to the sound pressure, and a quadrature component which does not contribute to the sound pressure. The technique is demonstrated on a test case and on a commercial loudspeaker driver.