Quietness, Comfortable Sound and Excellent Acoustics NAGATA ACOUSTICS

News 09-05 (No.257)

Issued : May 25, 2009

[ Japanese Version ]

Hiroshi Fujiwara Memorial Hall Opens in Keio Univ. "Collaboration Complex"

by Toshiko Fukuchi

Stage view (with sound reflection panels)
Stage view (with sound reflection panels)

Audience seating area
Audience seating area

Keio University marked its 150th anniversary with the construction of a "Collaboration Complex" of facilities at the school's Hiyoshi campus in Kanagawa Prefecture. The new complex, which completed construction in July 2008, is conveniently located in front of the Toyoko Train Line's Hiyoshi Station and alongside the Tsunashima Kaido avenue. In addition to Hiroshi Fujiwara Memorial Hall, which I will discuss in this article, the complex includes space for Keio's Graduate School of System Design and Management, Graduate School of Media Design, and Keio Business School, lodging for visiting researchers, childcare facilities, and, in separate structures, new athletic grounds with physical education facilities. The complex also has space for shops and restaurants and other support functions.

<< Collaboration Complex: Its Vision, Project Participants and Site Access >>

Except for the graduate school part of Collaboration Complex, all of its facilities are available for use by local residents, as well as by students and faculty. The university's decision to include the local community as a user group of the facility shows how strongly the concept of local and regional collaboration informed the planning and realization of this building.

Two architectural firms, Environment Design Institute and Mitsubishi Jisho Sekkei Inc., shared the architectural design responsibilities for the project. Tokyu Construction served as the general contractor. Nagata Acoustics participated on this project solely as the acoustical consultant for the design and construction of Hiroshi Fujiwara Memorial Hall.

Upon exiting the Toyoko Line's Hiyoshi Station, a street lined with beautiful ginkgo trees immediately greets the eye, creating an appropriate campus setting for Keio University, one of Japan's most prestigious private universities. Visitors to Collaboration Complex turn right and follow the Tsunashima Kaido avenue that parallels the train line to arrive at the complex's building, which has a white exterior is easy to recognize. In addition to access using the Toyoko Line, a new extension of the Yokohama Municipal Subway Line also has a stop with an entrance directly in front of Collaboration Complex. Either way, the complex's convenient location offers easy access via public transportation. Hiroshi Fujiwara Memorial Hall occupies the rear portion of Collaboration Complex's second floor.

<< Hiroshi Fujiwara Memorial Hall-A Concert Hall that Adapts for Lectures >>

Hiroshi Fujiwara Memorial Hall has 509 seats and is acoustically designed specifically for the performance of music with a shoebox configuration and one tier of balcony seating at the sides and rear of the hall. The hall's interior features abundant wood-grained finishes and seats upholstered in a softly colored hue that create a warm and inviting atmosphere.

While our acoustical design for Hiroshi Fujiwara Memorial Hall creates a concert hall space for music performance, the design also takes into consideration the university setting of this hall and the inevitability that it will sometimes be used for lectures, convocations and other events and ceremonies for which clarity of speech will be the priority. To address this need, we installed a variable reverberation system that uses sound absorbing curtains. Thus, for this hall, we created a room configuration and interior materials that provide satisfying concert hall performance characteristics as the foundation of the hall's room acoustical design and, within the context of this basic design, we planned and developed means to adapt the hall's acoustics for lectures and other speaking events.

In pursuing our room acoustical design objective of a concert hall that can be adapted for lectures (and similar speaking events), we benefited from collaboration with Environment Design Institute's Chief, Mr. Tadashi Saito. Mr. Saito has created the architectural designs for many theaters and this extensive experience has surely honed his understanding of room acoustics. In addition, Mr. Saito brings to his projects a dedication to fine acoustics that borders on obsession, making collaboration with him an acoustical consultant's dream come true.

<< Hiroshi Fujiwara Memorial Hall's Room Acoustical Design >>

Stage view (glass window with lace curtains)
Stage view (glass window with lace curtains)

Stage view (with sound absorbing curtains)
Stage view (with sound absorbing curtains)

Cross-section drawing
Cross-section drawing

Sound reflection panels above the stage
Sound reflection panels above the stage

Adjustable sound absorbing curtains along the sidewalls
Adjustable sound absorbing curtains
along the sidewalls

The entire rear stage wall of Hiroshi Fujiwara Memorial Hall is glass, and through the glass can be seen the new athletic grounds that are located behind Collaboration Complex. In front of the glass rear stage wall, we installed retractable lace curtains and curtains made of a thick, opaque, sound-absorbing material. We also installed movable sound reflection panels that can be stored away when not needed.

We intentionally designed the stage's sound reflection panels with eave-like protrusions so that valuable sound reflections will reflect back to the performers on stage. We also designed the sound reflection panels with varied sizes of vertical and horizontal ribs in order to promote sound diffusion. The implementation of these acoustical elements creates a visually beautiful design behind the performing musicians.

Because of the small size of Hiroshi Fujiwara Memorial Hall, we planned for the expected large influence of reflections from the hall's walls. Instead of smooth wall surfaces, throughout the hall we finished the walls with fine indentations and protrusions.

At the ceiling above the stage we installed a large reflection panel. Large spatial volume is generally a desirable quality in a hall because it is necessary to achieve ample sound reverberations. However, if the ceiling is too high, acoustically desirable sound reflections will not be obtained. By installing the sound reflection panel near the stage ceiling, we achieved both design objectives of appropriate spatial volume and sound reflections. Like the walls of the hall, the surface of the ceiling reflection panel is not smooth. Instead, we finished the surface with fine indentations and protrusions.

We installed the adjustable sound absorbing curtains along the sidewalls, starting at the edge of the stage and continuing into the audience seating area. We also installed the sound absorbing curtains in front of the stage's rear glass wall. The sound absorbing curtains cover a maximum total surface area of 270 sq. m. (2,900sq. ft) when fully unfurled. By adjusting these curtains, the hall's reverberation time can be set to between 1.1 and 1.8 seconds. This range is a specification that enables the hall to be adjusted to suitable reverberation times for a broad variety of performances and events, including both the longer reverberation time desired for classical music concerts and the shorter reverberation time needed to ensure excellent clarity of speech during lectures and other speaking events.

<< Sound Isolation in Hiroshi Fujiwara Memorial Hall >>

As I mentioned at the beginning of this article, Collaboration Complex provides space for a diverse assortment of purposes. Collaboration Complex's childcare facilities are located on the first floor, directly below Hiroshi Fujiwara Memorial Hall. Also, the Tokyu Electric Railway, Yokohama Municipal Subway Line and the Tsunashima Kaido avenue all pass in proximity to the Collaboration Complex site. To isolate the hall from external noise and vibration, as well as from sound produced in other Collaboration Complex spaces, we specified an anti-vibration structural design for the hall portion of the building. In testing conducted by Tokyu Technological Research Institute after the completion of construction, sound isolation between the hall and the childcare facilities on the floor directly below the hall produced a sound isolation performance measurement better than 80 dB (at 500 Hz). This level of sound isolation performance ensures that the hall and childcare facilities can be used simultaneously without any concern that the sounds from one room will impinge on the activities in the other space. We also achieved an HVAC quietness level of NC-20 or quieter. Noise from the outside rail and surface street transportation cannot be heard at all in the hall.

<< Hiroshi Fujiwara Memorial Hall-A Worthy Venue for Concerts >>

In the months since the official opening of Collaboration Complex and Hiroshi Fujiwara Memorial Hall, I have not yet had the opportunity to listen to a performance in the hall. However, shortly before the hall's completion, I listened to one of the architectural firm's personnel play the cello on the hall's stage and I found the hall to have a satisfying level of brilliance combined with sweet, warm acoustics.

This hall's acoustics put it on a par with other halls of similar size in the greater Tokyo Metropolitan area. I hope that the hall becomes a regularly booked venue for professional classical music concert performances.

Yokosuka Arts Theatre Stages Baroque Opera in its 15th Anniversary Year

by Makoto Ino

Japan's "Ongaku no tomo" publishing company publishes its biannual Grand Opera magazine each spring and fall for Japan's opera fans. For the past four years, I have had the pleasure of contributing a regular column to this publication. In my capacity as a Grand Opera columnist, I recently attended two baroque opera performances staged in celebration of the 15th anniversary of Yokosuka Arts Theatre. I also interviewed Yokosuka Performing Arts and Culture Foundation Operations Manager, Ms. Hikaru Amanuma, who is in charge of the facility's management and operations, and baroque opera's Stage Director, Mr. Tadashi Miroku.

<< Yokosuka Arts Theatre Overview >>

Floor plan
Floor plan

Large Hall (Interior View)
Large Hall (Interior View)

The Yokosuka Arts Theatre facility has a large opera house with a spacious stage and a horseshoe configuration that seats 1,800 and formally bears the "Yokosuka Arts Theatre" name, and a small hall of just under 600 seats named "Yokosuka Bayside Pocket." The facility also has large and small rehearsal rooms.

Yokosuka Arts Theatre is located about an hour's train ride southwest from Tokyo Station, very near the Keihin Express Line's Shioiri Station. It is also about a 10-minute walk from the JR Yokosuka Station.

<< Rich History of the Yokosuka Arts Theatre Site >>

From the time of Japan's Meiji Era (1868 - 1912), Yokosuka has been used as a naval base and, after the end of World War II, the U.S. Yokosuka Naval Base located at this port became well known both in Japan and internationally.

In 1933, a theater built for enlisted men in the Japanese navy opened on the Yokosuka Arts Theatre site. From 1945 to 1983, the building was reused as the Club Alliance Enlisted Men's Club serving U.S. enlisted men stationed at Yokosuka. For a while, the EM Club staged a prolific array of chansons, jazz, opera, ballet and other music and dance performers.

After its repatriation to Japan, the site became the focus of a municipal redevelopment project to construct a Yokosuka Cultural Center. The facility built as a result of that project is the Yokosuka Arts Theatre.

<< The Yokosuka Arts Theatre Project Completed in 1994 >>

Kenzo Tange Associates designed the architecture for the Yokosuka Arts Theatre and Nagata Acoustics served as the acoustical consultant from 1989, when the project's conceptual design phase began. Even before this time, Yokosuka City retained Japanese composer Mr. Ikuma Dan to be involved in all aspects of the project, from conceptual design through operational and administrative planning for the halls. (Previously, in 1982, the city also commissioned Mr. Dan to compose the "Yokosuka" suite for chorus and orchestra in celebration of the city's 75th anniversary as a city.)

Yokosuka Arts Theatre opened in February, 1994. Japan's Fujiwara Opera Company performed the inaugural program which featured Puccini's "Madame Butterfly."

<< Innovative Programming Culminates in 15th Anniversary's Baroque Opera >>

According to Ms. Amanuma, Yokosuka Arts Theatre began staging an introductory series of opera performances in the Yokosuka Bayside Pocket small hall in 1996. In 2003, Mr. Miroku took this opera outreach a step further by conceiving a series of productions under the series title of "Opera at Your Doorstep," in which he brought some lesser performed productions that contain humor to the stage. Over the course of six years, Mr. Miroku produced and directed 13 operas as part of the "Opera at Your Doorstep" series, putting in place a strong in-house chorus and stage crew, and building the facility's experience with sponsoring in-house productions. Now, Mr. Miroku has brought this experience to fruition in the large opera house by successfully directing the 15th anniversary performances of two baroque operas.

When the Yokosuka Arts Theatre project opened in 1994, we measured the opera house's reverberation time and obtained a value of 1.7 seconds (at 500 Hz). This proved a fine acoustical environment for the baroque operas I attended in celebration of the facility's 15th anniversary. The performances were accompanied by an ensemble made up of 12 or 13 ancient instruments, and these instruments provided an acoustically well-matched balance for the clear tones of the opera singers, creating a truly enjoyable musical blend.

Mr. Tadashi Miroku, whose talents also include being an accomplished countertenor, told me that in Italy audiences value the drama of operas. The singers are actors and the lyrics their lines. Audiences expect to be able to hear and comprehend the meaning of the librettos, so the acoustics of the opera houses there are deader than one might assume them to be. I left my interview with Mr. Miroku impressed by both his words about opera and opera house acoustics and his accomplishments at Yokosuka Arts Theatre.

Grand Opera vol.42 2009 Spring, Ongaku no tomo sha corp. (in Japanese)

Yokosuka Arts Theatre Homepage is http://www.yokosuka-arts.or.jp/

Nagata Acoustics Hosts a Talk by Architecture Prof. Shozo Motosugi

by Akira Ono

Architecture Prof. Shozo Motosugi
Architecture Prof. Shozo Motosugi

The acoustical consulting work of Nagata Acoustics gives us the opportunity to work and collaborate on a daily basis with world-class architects, stage designers and other hall and theater professionals. Periodically, we invite one of these professionals to give a talk at our Tokyo office. The talks last about two hours and we typically follow the talks with wine and cheese refreshments and time for casual conversation with the invited speaker.

On the Monday evening of April 6, we listened to Prof. Shozo Motosugi of the Nihon University College of Science and Technology Architecture Department. Prof. Motosugi's field is theater and hall architecture and stage technology planning. He has authored many research papers and monographs on topics in his field, and he has extensive hands-on project experience in the capacity of technical stage consultant for the design of many theaters and multipurpose halls. Nagata Acoustics consultants often find ourselves collaborating with Prof. Motosugi on the design planning of multipurpose hall projects.

<<Prof. Motosugi's Style of Collaboration on Projects >>

Collaborating with Prof. Motosugi is always a pleasure. His design proposals go beyond satisfying the functional requirements of a theater or hall to incorporate his original insights and ideas that are on the cutting edge of the stage technology profession.

Prof. Motosugi adopts a positive attitude towards even the most functionally challenging designs that may be proposed by project architects. Instead of knee-jerk opposition to unusual architectural designs, Prof. Motosugi focuses on understanding the essence of the architect's intent and figures out the minimum design modifications needed to achieve both the project's planned technical theater functionality and an architectural design as close to the architect's proposal as possible. This approach has earned Prof. Motosugi strong endorsements from a large number of architects.

On occasion, Prof. Motosugi's suggested compromise conflicts with our acoustical design requirements, so we always make sure to stay in the loop during any design modification discussions and present acoustical design requirements as the need arises. Prof. Motosugi has many years of experience collaborating on the planning for hall projects and we always find him receptive and understanding regarding the importance of projects' acoustical design requirements.

<<Prof. Motosugi's Talk >>

Prof. Motosugi began his talk by recounting how he became interested in the field of theater design. In 1968, Prof. Motosugi attended a performance at Shinjuku's Hanazono Shrine by Red Tent, which was under the direction of Juro Kara. At that time Red Tent was one of Japan's three major underground theater companies together with Japanese essayist and director Shuji Terayama and documentary filmmaker Makoto Sato. Prof. Motosugi says that the production impressed him so profoundly that it led him to become interested in theater and theater architectural design.

Later, when Prof. Motosugi began his academic career, he traveled abroad to Germany for internships at Deutsche Oper Berlin and Berlin's famous Schaubühne am Lehniner Platz, where he gained hands-on experience in opera and theater operations. Prof. Motosugi quoted Goethe's remark "In the end, we retain from our studies only that which we practically apply," and attributed some of his persuasive ability with architects to these overseas internships. His credibility comes not only from studying books in academic settings, but also from learning by doing at these highly respected German opera and theater venues.

Prof. Motosugi then turned his presentation to the topic of "Evolution and Obsolescence," focusing on the historical transitions in traditional Japanese theater spaces as revealed in paintings and "fusuma-e" (paintings on sliding wall panels). He also spoke about present-day regional kabuki theaters. For each period of Japanese theater that he discussed, he related the theater architecture to changes in the theatrical productions and acting, and the appearance of the audience and their seating arrangements, all in the context of what audiences of each period expected to see and hear, and what the actors performed. Prof. Motosugi spoke about Eiichi Shibusawa's introduction of Western theater to Japan during the Meiji Era (1868 - 1912) and the major changes that ensued as a result.

<<Prof. Motosugi's Role as Judge of Hall Project Design Competitions >>

Prof. Motosugi frequently serves as a judge on hall project design competitions. Typically, most of the other judges are maven architects from firms with strong name recognition. While the architects who cast the deciding votes in these competitions evaluate the designs using architectural parameters and preferences, it is also essential that the designs they select be viable from the technical functional perspective.

Whether the competition's goal is to select a concept proposal or an actual architectural design, we and many others highly value Prof. Motosugi's presence on these design selection panels. He ensures that design competitions select submissions that can successfully meet the technical and practical requirements for successful theater and multipurpose hall projects.

Our evening with Prof. Motosugi was both enlightening and enjoyable. We appreciated his taking the time to speak at our Tokyo office and look forward to collaborating with him on future projects.

Nagata Acoustics Inc.

(Tokyo Office)
Hongo Segawa Bldg. 3F, 2-35-10 Hongo
Bunkyo-ku, Tokyo 113-0033, Japan
Tel: +81-3-5800-2671, Fax: +81-3-5800-2672

(LA Office)
2130 Sawtelle Blvd., Suite 307A
Los Angeles, CA 90025, U.S.A.
Tel: +1-310-231-7818, Fax: +1-310-231-7816

(Paris Office)
75, avenue Parmentier
75011 Paris, France
Tel: +33 (0)1 40 21 44 25, Fax: +33 (0)1 40 21 24 00

E-mail: info@nagata.co.jp

[ Japanese Version ]