Church of San Gerardo hospital
On April 14, 2012 the church of the new San Gerardo hospital in Monza - designed by the architect Edrisio Bruletti - was inaugurated. As soon as the concrete structure was built, strong reverberation and resonance problems appeared deriving from the particular geometry of the room. Therefore, we intervened with an acoustic treatment proposal, flanked by Mauro Lavazza of Leading Technologies - for electric sound system - and the GGP Sound Alberto Ferraris for the installation of the sound absorbing false dome.Read more
When we have been called, only the concrete structure was done: the church had obvious acoustic problems because of the focusing effect of the dome. It was so annoying that it was impossible to catch the words of a person placed at over a meter and a half away. With the first acoustic surveys we measured extremely long T30 reverberation time values, of about 12 s, especially at low and low-medium frequencies. The situation looked rather critical especially considering that, at the time of the first measures, the room was not entirely closed, since it lacked doors and windows (for a total of at least 1/3 of the entire lateral surface).
The acoustic treatment design that we presented with the architect Edrisio Bruletti was based on three interventions:
- creation of a false ceiling in the shape of an inverted dome inside the dome: the system works as a low frequencies trap. This surface is convex and not concave, so it spreads the acoustic field homogeneously and not concentrated as before. The inside of the false dome is filled with sound-absorbing material and its surface is in perforated wood;
- coating of the walls with sound-absorbing plaster;
- choice of the sound diffusion system: a JBL CBT100LA line array. We made this choice for the efficiency of speakers in the reproduction of speech, for the narrow angle of vertical spread (which is useful not to work the dome in a negative way) and for the ease of inclination and mounting. We set up 4 speakers looking for the best way to create a homogeneous sound field throughout the church.
|Area||300 m2||Volume||1200 m3|
|Reverberation time||Ante-operam 11s; Post-operam 2.7s sala vuota, 1.9s sala piena|