Considerations about the acoustical properties of Teatro Nuovo in Spoleto after the restoration works Alessandro Cocchi (1), Marco Cesare Consumi (1), Ryota Shimokura (2) (1) – DIENCA, Engineering Faculty, V.le Risorgimento 2 – 40136 Bologna – Italy (2) – AIST, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 – Japan In 2003 the municipality of Spoleto decided to stop the performances within the Teatro Nuovo, among the others also of “Two World Annual Festival”, as it was necessary to modify some material, repair the floor, refurbish pictures and so on: the first author was charged of all the acoustical aspects and he decided to perform extensively acoustical measurements. During this measurement campaign, a flutter echo was detected in the stalls, so it become necessary to detect the origin of this problem, then to find some modification able to remove it: we have already presented our studies on this subject, from which a new design of the orchestra pit was derived. For fire safety reasons it was necessary also to remove some wooden elastic panels from the boxes, and an acoustically equivalent technical solution was adopted. As the acoustical parameters revealed a particular predisposition for Italian Opera performances (the first author was invited also to attend some of them), we decided also to renew the wall to wall carpet with a wooden solution, acoustically elastic, incorporating the heating plant. In this paper we will present the results of measurements performed after the opening of the theatre (a typical Italia Opera House of the end of the Eighteen Century) and some consideration about the acoustical results so obtained. 1.0 Scheme of the two measurement campaign The first measurement campaign in the theatre under test has been carried out in the year of 2002, the scheme used has been based by setting three omni-directional sources (dodecahedron) in the opened pit, in the covered pit and on the stage respectively, close to the proscenium arch, the position often used by the opera singers. The receivers (binaural dummy head), instead have been placed in 8 different positions in the stalls and 30 different positions in the boxes plus balconies: 6 receivers for each one of the 4 box orders and finally 6 receivers for the balcony. Thus, 38 receivers for each one of the 3 sources it gives a total of 114 binaural impulse responses. For more specifications about the adopted measurement method see reference [1]. Later, when the restoring works have been completed, a new measurement campaign have taken place looking for to maintain the same positions of the first measurements carried out in the 2002, with the aim to make a comparison between the two measurement campaign and thus to verify the differences due to the acoustical and architectural restoring works. Fig.1. On the left side: the various layers of the new flooring in the stalls. On the right side: the new structure of the ceiling of the boxes.