The most demanding issue in the field of acoustics is to design concert halls, theaters and movie theaters. Succeeding with the acoustical matters in such projects is only achieved by the collaboration of architechts, structure engineers, acoustical consultants and other designers. Acoustical functionality in challenging projects requires proper sound insulation capabilities of the structures, acceptable noise level of the HVAC-appliances and good room acoustics. The design of concert halls is nowadays made mostly by state-of-the-art modeling software.