Simulation Techniques: Loudspeaker Driver Displacement Decomposition

This article by René Christensen (BSEE, MSc, PhD), offers a valuable tutorial that discusses the unique possibilities of three-dimensional analysis of loudspeaker driver displacement, using Phase Decomposition and Axial-Symmetrical Decomposition techniques. The article demonstrates how a total displacement on a cone surface can be decomposed into different components directly in COMSOL Multiphysics, and how this can reveal some of the underlying mechanisms of the driver.

In this article, James Croft looks at a patent awarded to David Russell (Toronto, CA); and John French (Caledon, East, CA) on behalf of Audera Acoustics, Inc., Schomberg CA. The patent describes a generic acoustic high displacement transducer system, containing a diaphragm position sensing module, a controller with a transmitter, so that the voice coil moves at least partially in response to the control signal.

Anyone who is serious about designing a loudspeaker using dynamic drivers is either familiar with, or has used, Thiele/Small parameters, generally accepted as ways to predict driver behavior in different enclosures. But there are other measurement methods we can use to determine and quantify nonlinearities: the DUMAX system, produced by DLC Design, and the Klippel Analyzer System by Klippel GmbH. This article was originally published in audioXpress, March 2003.

NTi Audio introduced the Vibration Meter, built on the advanced technology employed in the XL2 Sound Level Meter. This enticing addition to the NTi product family, provides many functions for vibration analysis, allowing users to accurately measure acceleration, velocity and displacement simultaneously for frequencies down to 0.7 Hz. The results are presented with metric or imperial units, or as a dB value with an adjustable reference level.