The Salt Silo in Tvøroyri, The Faroe Islands, is set to be turned the largest concert hall in The Faroe Islands. The Salt Silo is a large old silo with wood and concrete walls, and currently acoustics which are not suitable for musical reproduction. The project leaders require the concert hall to be suitable for both classical and rock music, which poses an interesting acoustical challenge. In this paper I will go through which variables should be known and controlled to be able to acoustically analyze and design a concert hall such as The Salt Silo. To not become too large of a project, the paper will focus on the hall's lateral energy fraction and reverberation time. The paper will also look at the Clarity Index parameter (C80) and note how it is affected by the change of reverberation time. The concert hall will be simulated with Odeon auralization software by Brüel & Kjær, and the paper will present the author's suggestion of how the concert hall should be acoustically designed to optimize the values of the reverberation time and lateral energy fraction. The design objective is to create a hall which is suitable for classical music, but where the acoustics can be varied to be able to house modern rock concerts as well. The paper will present a suggestion as to how The Salt Silo should be transformed from an old silo to a modern concert hall which fulfills the criteria which the project leaders have set on reverberation time and lateral energy fraction.

This master thesis examines the effects on the acoustical properties of a concert hall caused by an artificial reverberation system (ARS) and the possibility of simulating these properties. By examining the case of the Stockholm Concert Hall, which recently installed such a system, a greater understanding of the ARS will be gained and additional improvements of simulating such systems will be explored. This study comprises two parts: (1) objective data obtained through acoustical measurements are evaluated both internally and to other halls and (2) by computer simulation of the concert hall and its electronic reverberation system evaluate the acoustics of the hall. The study shows that the effect of the ARS on the acoustical properties of Stockholm Concert Hall is not excessive but noticeable. An 0.3 second increase in reverberation time is a desirable outcome but comes at the cost of clarity, which sees a reduction of 0.7 decibels. Moreover, it is possible to simulate a concert hall, having an ARS installed, with fairly realistic results. However, in order to compile the simulated impulse response, a script had to be created -combining the transfer functions related to each component of the reverberation chain from source to receiver, including all the microphones and loudspeakers of the ARS. / Det här examensarbetet undersöker påverkan på de akustiska egenskaperna hos en konsertlokal orsakad av ett artificiellt efterklangssystem. Likaså undersöks möjligheterna för att simulera dessa akustiska egenskaper. Genom att undersöka Stockholms konserthus, som nyligen installerade ett efterklangssystem, kommer en bättre förståelse för artificiella efterklangssystem skapas och ytterligare förbättringar för simulering kommer att möjliggöras. Den här studien genomförs i två delar: (1) objektiv data, inhämtad från akustiska mätningar, utvärderas både internt och mot andra konsertlokaler samt (2) genom datorsimulering av konsertlokalen och det elektroniska efterklangssystemet utvärderas de akustiska egenskaperna. Studien visar att inverkan på de akustiska egenskaperna hos Stockholms konserthus orsakade av det artificiella efterklangssystemet inte är överdrivna men noterbara. En önskad ökning av efterklangstiden med 0.3 sekunder uppnås men detta på bekostnad av att ljudets klarhet minskar med 0.7 decibel. Vidare är det möjligt att simulera ljudutbredningen i en konsertlokal som har ett efterklangssystem installerat med ett tämligen realistiskt resultat. För att uppnå detta simuleringsresultat skapas ett skript vilket väger samman alla överföringsfunktioner mellan ljudkällan och mottagaren, inklusive de mellan efterklangssystemets mikrofoner och högtalare.