From the moment the Ateliers Jean Nouvel produced the 3D blueprints to its construction by six carpenters, barely four months were needed to build the 1/10th scale model of the Philharmonie de Paris auditorium. Entirely made of wood, it was assembled on the Philharmonie de Paris site at the Parc de la Villette, on November 8, 2008. The model is the fruit of a high-tech collaboration between the Georg Ackermann workshop and engineer Markus Honka. The two have already worked together on the Elbe Philharmonic acoustic model designed by Swiss architects Herzog and de Meuron, due to open in Hamburg in 2011.
An entire team of specialists was needed for this vast 3D puzzle of over 900 pieces, which was put together in the Georg Ackermann GmbH workshop in Wiesenbronn, near Nuremberg (Bavaria). Engineer/designer Markus Honka began the process, using 3D blueprints to determine the structure and assembly plan of an initial model scaled to 1/100th, from which the 1/10th model was created. Honka also lightened the model to respect floor load restrictions, so that the Philharmonie de Paris premises would be able to support the weight of this mini-auditorium. Algorithmic geometry specialist Benjamin Samuel Koren from 1:One company handled the computer programming. This was then translated into machine language by Manfred Weid and his team for the manufacturing of various parts on a powerful 5 axis machine.
Once assembled, the 1/10th model was subjected to a certain number of acoustic tests (impulse response, direct listening, etc.) The tests were conducted by two experts, Yasuhisa Toyota, head of Nagata Acoustics, who worked on the Hamburg project and the Walt Disney Concert Hall in Los Angeles, and New Zealander Harold Marshall, acoustician on this project.
The tests helped to detect any echo effects that calculations cannot simulate. They also validated the hall’s acoustic qualities, which were determined by computer simulation during prior phases. To allow proper testing, the model reproduced all of the auditorium’s details at a 1/10th scale. The audience was represented by 2,400 styrofoam dolls. Air was replaced by nitrogen to restore the acoustic absorption of air at frequencies used at this scale.
All of the tests used the impulse response method. A very quick sound (equivalent to a clap) was transmitted through a speaker inside the model. The response to this sound impulse was captured by microphones, then digitally analysed. Two kinds of microphones were used. The first kind – called “binaural” – simulated the audience’s listening experience. A doll was equipped with two microphones – one per ear – and moved around the model to test listening conditions at various points around the “auditorium”. The second kind – called “monaural” – used a single microphone that captured sound from all directions to evaluate the auditorium’s physical characteristics.
If echo effects were detected, the acousticians suggested various corrective measures, such as adjusting the angle of certain reflective surfaces, or using elements that diffuse or absorb sound.
