Racetrack Drive Unit - Pre-Processing

In some circumstances where space is restricted, it is necessary to maximise the radiating area of the driver to achieve a required sound output level.  This often means that a non-round loudspeaker is employed.  These drive units have diaphragm resonances which are generally more spread over frequency but can produce high amounts of harmonic distortion if not designed to keep resonance under control.

Illustrated is a typical non-round loudspeaker called a "racetrack".  Clearly these will fit into confined spaces and achieve a much greater radiating area than a round loudspeaker with only the radius of the minor axis.

Photos of Racetrack Drive Units

   
CAD Definition

 

In terms of modelling these loudspeaker and to minimise computational effort, a ΒΌ model is used with appropriate symmetry conditions applied such that it behaves as if the entire loudspeaker was present.

Model Reduction Strategy

 

Pre-processing of the model including the prescription of material parameters, loads and restraints and the application of acoustic boundary elements is undertaken before solving.

Meshed Structure and Acoustic Regions

 

Acoustic Display Planes and Microphones