Resonant cavities and acoustics vases in Italian Opera Houses; the "Teatro Principal" of Valencia and the eighteenth century treatises about theatres

Abstract

This paper describes the research job carried out at Polytechnic University of Valencia-Spain-about resonant cavities placed under the orchestra pits of Italian Opera Houses, and others acoustics mechanisms like this one. The Teatro Principal of Valencia was built following the Project developed by the Italian architect Felipe Fontana in 1774 and it opened its doors in 1832. Fifteen years ago, in the last architectonic intervention in this theatre, almost a hundred of acoustic vases were found in one of those resonant cavities. What acoustics role they accomplish? How they "functioned"? This was the starting point to study this kind of artifices, throughout the eighteenth century European treatises about theatres and in our Teatro Principal.

Evaluation of Acoustic Features after Refurbishment Works Inside Two Historical Opera Theatres Located in Italy

“…Overall, considering the average values of all the measured points, as shown in Figure 5, the results indicate that the sound is more robust with the empty cavity, especially regarding both the reverberation time and the sound pressure levels [12]. These outcomes are in line with the subjective response perceived by musicians in 1992 [13].…”

“…The sound levels across the theatre with the empty cavity were increased by 5-8 dB [9,12]; The values of EDT, T 15 , and T 30 were constantly increased by 15-20% at each frequency band with the condition of the empty cavity [9]; The clarity index for music (C 80 ) resulted as being invariant, with a negligible drift between the two conditions [9].…”

“…The measurements undertaken inside the Teatro Alighieri of Ravenna aim to highlight the importance of the resonance cavity beneath the pit floor and the relative beneficial effect for the acoustic parameters [9][10][11][12][13].…”