The architectural acoustic design for a multipurpose auditorium: Le Serre hall in the Villa Erba Convention Center.

Large spaces, circular in plan, can be preferred by architects to design large auditoria, even though they can cause acoustical singularities such as focusing and whispering gallery. In large auditoria for multipurpose functions are becoming a common request to use the space for different activities such as conferences, concerts of classical and amplified music, shows, etc. and the necessity to find architectural solutions in order to consider the variable acoustic demands according to different possible layouts, are growing. In this paper, as a case study, architectural acoustic design approaches and solutions for a  circular auditorium are presented. The case study was made in "Le Serre" hall for 1000 people, in the Villa Erba Convention Center, located in Cernobbio (Italy), in which different combinations of movable architectural elements are developed to create a multipurpose space. A geometrical acoustic analyses are included, followed by the description of different methods to avoid focusing and whispering. Room acoustics procedures and implementations of computer simulation techniques are developed.