The Lumped Speaker Boundary condition is used to model a loudspeaker (dust cap, cone, surround assembly, and motor) or another transducer using a lumped representation with a coupling to an
Electrical Circuit interface. The condition is applied at the location of the speaker diaphragm (on a surface with the driver equivalent area). The mechanical and electric properties of the speaker can, for example, be described through the classical Thiele-Small parameters and associated lumped circuit. In general, any circuit representation can be set up in the
Electrical Circuit interface and used. The properties of a back volume are also modeled using a lumped representation through either a simple equivalent acoustic compliance, an RCL circuit, or a user-defined impedance.
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 an RCL circuit, 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 Interior 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.