Diaphragm Design

The diaphragm (or membrane) of the speaker/driver is what transforms the alternating magnetic field generated in the voice coil into the pressure variations known as “sound”. In most cases, the ideal diaphragm should convert the applied voltage into piston-like movements regardless of frequency and amplitude. This is no easy task since phenomena like breakups and rocking modes, material nonlinearities etc. occur in the real world. Being able to predict and measure these imperfections can speed up a design process significantly.

Previously diaphragm design relied on “cut-and-try” approach based on many years of experience of do’s and don’ts. This method is very time- and cost ineffective and even if huge resources are invested, there is no guarantee that the optimal design and performance has been reached. At Ole Wolff we have a faster and more reliable way of designing and optimizing diaphragms.

COMSOL Multiphysics® allow us to design diaphragms for various sizes of transducers where parameters such as foil type (single or multi layers), thicknesses of the foils, geometry of suspension, piston area and shape, number of stabilizing grooves in the diaphragm surface etc. can be simulated and performance verified before any mechanical tooling process is entered. This combined with years of experience assures shortest lead time and closest match to performance targets.

The Klippel Scanning Vibrometer System (SCN) enables us to measure and visualize the diaphragm behavior and adjust and derive material parameters for the Comsol model for further optimization.