ACOUSTICAL IMPROVEMENT OF A HISTORICAL OPERA HOUSE USING ROOM 
SIMULATIONS 
L. Parati a ’ *, A. C. Gade b , R. Pompoli a , J. H. Rindel b 
a Dipartimento di Ingegneria, Università di Ferrara, Via Saragat 1,44100 Ferrara, Italy (lparati, rpompoli)@ing.unife.it 
b 0rsted-DTU, Acoustic Technology, Technical University of Denmark, build.352, 
0rsteds plads, DK-2800, Kgs.Lyngby, Denmark (acg, jhr)@oersted.dtu.dk 
KEY WORDS: Opera House, acoustic simulation, acoustic heritage 
ABSTRACT: 
In the field of acoustics new techniques have been developed in order to improve the acoustics of a room. Techniques, such as 
computer simulations, are especially useful in historical theatres where acoustical characteristics can be preserved during renovations 
or improved with well chosen minor alterations while still preserving the theatre’s heritage. These new techniques have been applied 
to investigate the acoustical balance between a singer on the stage and the orchestra in the pit which is a relatively new concept in 
room acoustics. Simulations have been carried out in a model of the Royal Theatre of Copenhagen, which was inaugurated on the 
15 th of October 1874. By means of a few modifications in the type of materials, dimensions and shapes, some of the architectural 
elements controlling the balance have been identified and optimised. 
1. INTRODUCTION 
Historical opera houses are a heritage that has to be preserved. 
This heritage doesn’t have to be based only on the architectural 
aspects but also on characteristics such as its acoustical 
qualities. The concept of acoustical heritage has been 
determined in a document called “Charter of Ferrara” (Prodi, 
Pompoli, 1999), and a scientific tool to quantify the acoustical 
heritage has been described in the “Guidelines for acoustical 
measurements inside historical opera houses” (Prodi, Pompoli, 
2000). 
IS03382 (IS03382, 1997) can be considered the normative 
reference for this kind of room-acoustical measurement and the 
above guidelines, aim at specializing the norm for these 
historical places. Nowadays the acoustics of the historical opera 
house can be modified and problems solved. Among them one 
of the new aspects which still has not been sufficiently 
investigated is the acoustical balance between the sound coming 
from the orchestra in the pit and that from the singer on the 
stage. 
In order to best describe this acoustic aspect which is also 
important in modem opera houses, an omnidirectional sound 
source has to be placed in the orchestra pit and a directional one 
has to be placed on the stage (Parati, Otondo, 2003). By means 
of room acoustical simulations, it is possible to predict the 
acoustical behaviour. 
The aim of this study is to determine a method to control the 
balance through modification of architectural elements, without 
affecting the other acoustic parameters. Furthermore it is 
desirable to enhance the acoustic qualities of an existing theatre, 
preserving the historical heritage by means of room acoustic 
simulations carried out in this case on a model of the Royal 
Theatre of Copenhagen. 
The Royal Theatre (Royal Theatre websites) has been housed 
on Kongens Nytorv in Copenhagen since 1748. During the 
eighteenth and nineteenth centuries a new majestic theatre was 
built in the same place for a larger number of people. It was 
designed by the architects Vilhelm Dahlerup and Ove Pedersen. 
It was inaugurated on 15th October 1874. The theatre has an 
Italian Baroque style, the hall has a horseshoe shape and it 
houses 1400 people located in the stalls and the four levels of 
balconies. The stage tower has a volume of 13.000 m 3 with a 
stage area of 595 m 2 and a fixed proscenium of 115 m 2 . The pit 
has variable configuration based on the required dimension 
suitable for the orchestra. The pit floor area can reach a 
dimension of 130 square metres, which means full orchestra. 
Nowadays it is used throughout the year for opera, ballet and 
drama. This is the theatre where August Bourhonville worked 
and founded his famous ballet tradition. Figure 1 shows a view 
of the theatre from the outside. 
Figure 1: Exterior view of the Royal Theatre of Copenhagen. 
Corresponding author.