News 15-01 (No.325)
Issued : January 25, 2015
Radio France Opens L’Auditorium de la Maison de la Radio
By Dr. Yasuhisa Toyota
Last autumn, on November 14, 2014, a new concert hall opened in Paris, France. During the three months of September to November, four new halls with acoustics designed by Nagata Acoustics opened around the world—one in Shanghai, one in Katowice, Fondation Louis Vuitton in Paris and Radio France’s new hall, also in Paris.
Exterior of Radio France (at left) with Eifel Tower (at right)
<< Radio France and Its Two Orchestras >>
Radio France—France’s public broadcasting organization—is headquartered in Paris. Radio France administers two orchestras, Orchestre National de France and Orchestre Philharmonique de Radio France. Compared with England’s BBC and Germany’s public radio stations that have regionally-based orchestras, Radio France differs from the organizations in those countries. Instead—quite extraordinarily—Radio France has two orchestras under its auspices, both located in Paris and both full-size orchestras.
No other public broadcasting organization that I know of supports two full orchestras. For example, the Japan Broadcasting Corporation (NHK) supports one orchestra and even the notion that it might be able to support a second orchestra is inconceivable. Radio France’s support of two orchestras evidences its deeply engrained commitment and attachment to this music genre.
Orchestre National de France and Orchestre Philharmonique de Radio France are each run by a separate administrative organization and each has its own musicians. Until the opening of the new hall, both orchestras used Radio France’s “Studio 104” for their rehearsals, a large studio that accommodates about 300 chairs at Radio France’s Paris headquarters’ building. Also, until the opening of the new Radio France Concert Hall, the orchestras performed at two separate venues. Orchestre National de France performed at Champs Elysees Theatre and Orchestre Philharmonique performed at Salle Pleyel.
The new Radio France concert hall, named “L’Auditorium de la Maison de la Radio” is located adjacent to Studio 104. The two orchestras will both move their rehearsals and their performances to the newly opened concert hall.
<< Overview of the Project >>
The Radio France concert hall project began as a 1,500-seat hall. During the design phase, the client added a pipe organ to the requirements. To accommodate the pipe organ without changing the footprint of the room, the seat count needed to be reduced to 1,460 seats.
The local Paris architectural firm Architecture-Studio served as the project architect. Nagata Acoustics participated as the acoustical consultant for the room acoustics of the new hall. The Parisian company Lamoureux Acoustique provided acoustical consulting services for sound isolation and noise control.
<< A Design with Multiple Balconies >>
Plan (main floor level)
Plan (sound reflector level)
On this project, our room acoustics design work put special attention to two key topics. The first topic involved the constraints of the hall’s available space combined with the client’s request to be able to seat 1,500 patrons. In order to fit 1,500 audience seats in the square, 40 m. x 40 m. space allotted for the new hall, we knew that we would need multiple balconies. A first aim in connection with the balconies was to minimize the number of seats that would be below the overhang of a balcony, because it is difficult to achieve excellent acoustics under a balcony overhang.
Therefore, we decided to make the balcony depths as shallow as possible. This design decision increased the number of balconies required to meet the desired seat count. At the same time, we also needed to keep in mind how to achieve an overall spatial volume that would produce excellent acoustics and a shape that would efficiently produce abundant and beneficial early sound reflections. We used computer simulation studies to guide us to the best design for all of these requirements.
<< Preventing Echoes >>
Our second key topic—or challenge—concerned how to prevent the sound reflections generated off the hall’s back wall from producing undesirable echoes. Because our design goals included placing the audience seating as close to the stage as possible, we quickly adopted use of an arena configuration for the hall’s basic design, with audience seating on all sides of the stage. This configuration also matched the project architect’s wishes. As we developed the arena configuration design within the limited overall footprint, the hall’s outline took on a circular shape, which, from the acoustical perspective is unfortunately a shape prone to echoes.
Computer simulation studies alone are not a sufficient tool for ensuring the complete elimination of echoes. The best way to detect echoes before building a hall is the somewhat costly method of building and testing in a 1/10 scale model. In the case of the Radio France hall, with its round configuration, use of a 1/10 scale model was an essential step in our design process.
One effective strategy that we implement when working with a fundamentally concave round shape is to add small convex cylinders on top of the concave shape. In addition to eliminating undesired sound focusing of sound reflections generated off the concave surfaces, this design improves the balance and distribution of the sound reflections throughout the hall. We implemented this strategy in L’Auditorium and tweaked it based on testing in the 1/10 scale model. As a result, we effectively eliminated all possibility of echoes and created a smooth and balanced sound reflection distribution throughout the audience seating areas.
<< Post Completion Findings >>
L’Auditorium interior (side view)
L’Auditorium interior (view from chorus’ seating section)
We measured the completed hall’s reverberation time to be 2.0 seconds (at 500 Hz, in an empty hall). Based on this value, the calculated reverberation time when the hall has a full audience is 1.8 seconds (also at 500 Hz). The hall has a total spatial volume of approx. 14,500 m3
The orchestras held their first rehearsals in the hall one week before the hall’s opening, with one orchestra taking the stage after the other’s rehearsal finished. I had the pleasure of hearing the hall produce acoustics that gave clarity to each instrument’s sound as well as rich overall acoustics. In particular, I found that the soft and very soft piano and pianissimo dynamics waft beautifully through the space.
During the first rehearsal, the fortissimo sounds came across very forcefully. Because the audience seating is truly close to the stage, at this first rehearsal the fortissimo sounds seemed to predominate. Early in each orchestra’s rehearsal, there was a bit of a tendency to crank out the louder portions of the music. This kind of straining is typical of how orchestras play in many halls, and unnecessary in a hall such as the new Radio France L’Auditorium that has sensitive acoustics.
Invariably, it takes some amount of time for orchestra players to feel truly at ease in their new home and to learn to relax a bit and trust the hall’s acoustics. I am always asked how long the “breaking in” period of a new hall lasts. There’s no clear standard or single answer to that question. Nevertheless, as a rule of thumb, I advise clients that it’s a good idea to allow two to three months for the musicians to get to know their new hall. Based on the reviews after the L’Auditorium inaugural performances, Radio France’s two orchestras redefined what it means to be a “quick study” and both orchestras are already well on their way to perfecting their performances in the new hall.
National Taichung Theater Holds Gala Inaugural in Taichung, Taiwan
By Chiaki Ishiwata
The mayor of Taichung speaking congratulatory remarks
Ribbon cutting ceremony at the theater
In four previous articles we featured the progress of Taichung City's new opera house project (designed by Toyo Ito & Associates). Most recently, we wrote in the February, 2014 newsletter about the project's "topping out" milestone. Now I am happy to share the news of the National Taichung Theater's inauguration and ribbon-cutting ceremonies, which were held on November 23, 2014.
On the day of the inaugural events everyone attending the event gathered under beautiful blue skies for the celebration. The Taiwanese dignitaries included President Ma Ying-Jeou and the mayor of Taichung, who each offered words of congratulations. The official ribbon-cutting ceremony followed a performance by the National Taiwan Symphony Orchestra that created and enhanced the festive mood. After the ceremony, the Taiwanese opera troupe Ming Hwa Yuan Arts & Cultural Group performed the opera Cat Man in the opera house’s Grand Theater.
This project began as the “Taichung Metropolitan Opera House”. In April 2014, the Taiwan National Performing Arts Center project named three new facilities Taiwan’s “golden triad” of new performing arts venues. One of the named venues is the new opera house in Taichung and the other two are the Taipei National Theater and the Wei Wu Ying Center for the Arts currently under construction in Kaohsiung. The Taichung Metropolitan Opera House received the new name of National Taichung Theater and it was decided that the national government will take on the responsibility for the new theater’s operations. For the ribbon cutting and inaugural ceremony, Taichung City sponsored the event because the inaugural preceded the transition to a national opera house.
Exterior of the National Taichung Theater
Taichung residents enjoy the illuminated plaza
Starting at the end of last summer the fence around the project site and scaffolding on the outside of the building began to be removed, making visible the building exterior that—until now—we saw only in models and computer-generated renderings. Passers-by increased as did the number of people who stopped to admire the new structure. In addition, about a month before the ribbon-cutting and inaugural event, lights on the outside of the building started to be illuminated in the evening and multimedia projection mapping events were held on the theater’s exterior surfaces. Each milestone and event increased local interest in the structure so that more and more people came out to attend the events and I’m told that local traffic even came to a standstill at times as Taichung residents competed to see the new building and events happening on its campus. The city installed various artworks in the plaza and walkways near the theater building. Residents who come to stroll in the area can enjoy these additions as well as see the striking new building.
Performances and events related to the inaugural seemed to have been held until the end of last year. After the Chinese (lunar) New Year, which is on February 18, 2015, the building will transition to being run under the auspices of the national government. At that time, scheduling for use of the theater’s Grand Theater and other facilities will proceed toward the grand opening planned for autumn of this year.
Nagata Acoustics Inc.
Hongo Segawa Bldg. 3F, 2-35-10 Hongo
Bunkyo-ku, Tokyo 113-0033, Japan
Tel: +81-3-5800-2671, Fax: +81-3-5800-2672
1990 S. Bundy Drive, Suite 795
Los Angeles, CA 90025
Tel: +1-310-231-7878, Fax: +1-310-231-7816
75, avenue Parmentier
Tel: +33 (0)1 40 21 44 25, Fax: +33 (0)1 40 21 24 00