Evaluation of a reverberation enhancement system installed in a small multi purpose hall

After design and installation of a reverberation enhancement system in new 400 seat multi purpose hall in Vejle, Denmark. room acoustic measurements and listening tests were performed in order to reveal the objective and subjective performance and limits of such a powerful tool for altering ''room acoustic'' properties. The compromises in realistic choice of acoustic parameters for the different settings of the system are described with reference to the natural acoustics and functional needs of the hall in question. Although the enhancement system is capable of increasing the reverberation time by a factor of three, it is found that an increase of about 50% (from 1.1 to 1.7 sec.) is about the limit beyond which critical listeners start complaining about lack of realism. Possible reasons for this are discussed.