Correction of a strong seat-dip in the Teatro Argentino of la Plata in Argentina

The acoustic quality of the new Teatro Argentino de la Plata received various unfavourable comments from musicians, critics and the general audience after its inauguration in 1999. The lack of bass frequencies, low sensation of envelopment, a flat sound—i.e., a sound that seems to come only from the front and does not surround the listener—and a strong seat-dip on the main floor were highlighted. After carrying out acoustical measurements and developing a digital model of the hall, the analysis showed, on the main floor level, a deficit of acoustical energy in the first 100 ms after the direct sound and insufficient lateral energy. To correct those problems a new acoustical canopy, made with a distributed array of rectangular panels, was placed over the pit. The situation improved substantially, but there was still a minor seat-dip in the stalls. A restauration was undertaken in 2016, which included the replacement of the seats, and it was seen as an opportunity to further fix the residual seat-dip problem. This paper briefly describes the action of the new canopy related to the seat-dip and the criteria for choosing the new seat model.