The Lumped Speaker Boundary condition is used to model a miniature loudspeaker (dust cap, cone, surround assembly, and motor) or another micro-transducer using a lumped representation with a coupling to an
Electrical Circuit interface. The mechanical and electric properties of the speaker can, for example, be described through a Thiele-Small parameter representation and associated lumped parameters. The properties of a back volume are also modeled using an impedance expression.
Define how the Speaker area (projected) of the speaker is computed by selecting either
Selected boundaries (the default) if all boundaries are present, or
Use symmetries if the speaker surface is only partially represented.
When Use symmetries is selected, select the
Speaker area multiplication factor Ascale as
Automatic (the default, the model is analyzed for the presence of symmetry conditions); or
User defined and enter a value (default is 1). The settings are required in order to compute the effective area of the speaker which is used to compute the acoustic load and radiated power.
Define the Speaker axis direction eax by selecting
Automatic (the default) or
User defined. For the automatic option the axis is computed as the average of the surface normals, this option is valid if a full speaker surface is selected. The
User defined option should be used if the speaker surface is only partially represented and is the only option when
Use symmetries is selected.
The Lumped Speaker Boundary does not model the acoustics on the back side of the speaker cone explicitly. The properties can be entered either through a volume giving a simple compliance effect, through a simple RCL model, or through a user defined acoustic impedance of the back volume.
This section gives information about the state of coupling/connection to an Electrical Circuit interface. If the Lumped Speaker Boundary is not connected the text
Connect to ‘External I vs. U’ in the Electrical Circuit interface text will be displayed. Once connected a reference with a tag to the associated
External I vs. U node, in the Electrical Circuit interface, is displayed.
Select Use slip to get a tangential slip condition on the velocity, the velocity is only coupled in the normal direction to the surface. When not selected (the default) the full velocity component is coupled.