A radiatterer is a geometry that both acts as a radiator of sound as well as it scatterers the radiated sound waves. In addition to the problem of irregular frequencies, it is well suited to compare resonance amplitudes yielded by different methods and different types of finite and boundary elements. Furthermore, the numerical methods should investigate whether mesh refinement in regions with large gradients is necessary or can be neglected. A detailed description with references can be found in the PDF description. Available solutions: Steffen Marburg's solution using the Boundary Element Method: LA_Case2_Radiatterer_SteffenMarburg.pdf