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 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 the back volume are modeled using a compliance or a general RCL representation.

In the time domain, nonlinear effects can be included in the lumped model through parameters that depend on the axial position x or velocity v of the speaker. These are, for example, the typically measured BL(x), CMS(x), or RMS(v). Predefined variables exist for the axial velocity tatd.lsb1.v_ax and an ODE is solved for the associated axial position tatd.lsb1.x_ax (use the appropriate physics and feature tag). These variables can be directly used in expressions in the electric components in the Electrical Circuit model as they are globally defined.

If the speaker represents an interior boundary, with air domains on both sides, and the back volume is modeled explicitly; then use the Interior Lumped Speaker Boundary condition.

For the Speaker Geometry, Circuit, Mechanical, Thermal, Constraint Settings, Exclude Edges, and Exclude Points sections see Lumped Speaker Boundary in The Thermoviscous Acoustics, Frequency Domain Interface.

For the Back Volume Correction and the Initial Value sections see Lumped Speaker Boundary in The Pressure Acoustics, Transient Interface.