Vibrational Modes on a Loudspeaker Diaphragm

Insights into vibrational modes in both 2D axisymmetric and 3D coordinates are important for a fuller analysis of dynamic loudspeaker behaviour.

The images below show the same loudspeaker driver modelled in 2D axisymmetric and as a 3D half model.  In 3D, it is possible to load the structure and excite 3D mode-shapes - 3 of these are compared with axisymmetric mode-shapes at the same frequency below.












In many cases, 2D models offer a significant modelling speedup without losing the most important information to the designer.

Sometimes however, where non-axisymmetric loading or geometrical features are involved, 3D models provide the required solution.  Polar and Cartesian symmetries can be exploited to minimise computational expense.