The default for The Pressure Acoustics, Boundary Mode Interface is to use an iterative solver for 3D models and a direct dense matrix solver for 2D problems. If the
Far-Field Approximation is turned off, the direct dense matrix solver will be used in all situations. The dense matrix solver is adequate for small BEM problems but quickly runs out of memory for increasing number of DOFs.
When the Stabilized formulation is used a different solver suggestion is generated. Make sure to reset the solver to default if changes are made. The solver uses PARDISO as a direct preconditioner and GMRES as the iterative method.