Quietness, Comfortable Sound and Excellent Acoustics NAGATA ACOUSTICS

News 11-11 (No.287)

Issued : November 25, 2011

[ Japanese Version ]

Soka University of America Performing Arts Center Opens

By Motoo Komoda

Building exterior
Building exterior

The new Soka Performing Arts Center completed and opened on the Soka University of America campus in Aliso Viejo, Orange Country, California, U.S.A. The inaugural concert took place on September 17, 2011.

<< Project Overview >>

The new four story building features a 1,000-seat, multipurpose main hall and a multipurpose black-box theatre that accommodates up to 150 occupants. In addition, the building has practice rooms, offices and other support rooms.

ZGF (Zimmer Gunsul Frasca Architects) designed the building, Auerbach Pollock Friedlander served as the stage consultant and McCarthy was the general contractor. Nagata Acoustics was the project's acoustical consultant, participating from the design phase through construction and project completion. Our services included both acoustical room design and sound isolation design and project oversight. The overall cost of this project was $73 million.

In this article I will introduce readers to the center's 1,000-seat, multipurpose main hall.

Stage configured for orchestral performances
Stage configured for orchestral performances

<< The Main Hall's Unconventional Design >>

Multipurpose halls on school campuses usually have designs and configurations optimized for school convocations and lectures attended by large numbers of students. Some readers may have memories of this kind of typical school auditorium with a wide stage at one end. By comparison, the Soka Performing Arts Center Main Hall offers students a hall design that has many unique features and acoustics not often found in multipurpose halls built on school campuses.

On this project, the school was represented by a team of people who have a strong interest in the school's performing arts education program. In particular, the school's representatives included classical music enthusiasts who convincingly articulated their plans for school-sponsored subscription series of music concerts by local professional orchestras and other ensembles and performers. While it is expected that these kinds of events may use the hall on only a limited number of days each year, the project's client made this purpose a priority in the hall's programming.

In addition to its focus on classical music concerts, this multipurpose hall has unique interior architecture. The combination of classical music programming and unconventional interior design ensured that the project prioritized the acoustical goals for the hall and implemented a number of innovative design solutions.

Thrust stage
Thrust stage

Stage configured with stage curtains
Stage configured with stage curtains

Cross-section drawing of visible architectural ceiling, acoustical ceiling, and sound absorbing curtains
Cross-section drawing of visible architectural ceiling,
acoustical ceiling, and sound absorbing curtains

<< Stage Options and Seating Arrangements >>

Instead of the traditional auditorium configuration of a performance stage at one end of the room and the audience seating filling the space between the stage and the other end of the room, the Soka Performing Arts Center Main Hall has a stage that can seat a full-size orchestra and banks of seating placed in an arena-style layout around the stage. This layout minimizes the distance from audience seating to the stage and facilitates the hall's sense of intimacy and connectedness.

In addition to the full-size stage configuration for orchestral concerts, side portions of the stage can be lowered and seating rolled out over these areas to create a thrust stage configuration. Also, curtains hung from stage batons can be used to approximate a proscenium stage configuration. Theatrical productions have the limitation that the hall does not have equipment for raising and lowering curtains and scenery or spacious side wings. Overall, the three stage configurations make possible a broad range of performing arts productions and events.

When the hall is configured for orchestras, the floor of the first row of audience seating is at the same height as the stage floor. This arrangement gives the people sitting in this row the opportunity to enjoy a rarely experienced level of intimacy with the performance.

<< Visible Architectural Ceiling and Acoustical Ceiling >>

The hall has two ceilings, one that functions as the visible architectural ceiling and one that functions as a ceiling acoustically. The accompanying photos of the hall interior show the gracefully curved, suspended wood panels that form the visible architectural ceiling. Above this ceiling, we installed a very rigid and heavy acoustical ceiling. From an acoustical perspective, the two ceilings' functions differ dramatically. The curved panels allow the hall to benefit from the large spatial volume between the suspended panels and the acoustical ceiling above them so that, acoustically, the hall has a high ceiling and rich acoustics.

When we designed the curved ceiling panels we paid special attention to achieving a design that makes the panels as acoustically transparent as possible, a process that required multiple design iterations. The implemented design is a good example of how visible architectural elements and acoustical room design needs can be effectively combined.

<< Acoustical Curtains >>

To maximize the hall's adaptability to the venue requirements of many diverse kinds of events, we installed an adjustable acoustical curtain mechanism in the hall. We hid the electrically operated curtain sections from both the audience and on-stage performers by locating them above the visible architectural ceiling's panels and behind panels at the rear of the stage.

The acoustical curtain mechanism can be easily operated with the push of a button to horizontally open or close the curtains in a matter of a few minutes. When the hall is configured with the stage for full orchestra, the hall's reverberation time (at 500 Hz) measures 2.4 seconds without the acoustical curtains and 1.8 seconds when the curtains are fully extended. We also listened aurally to the reverberation and confirmed that the human ear can hear the considerable change in the hall's reverberation time when the acoustical curtains are open compared to when they are closed.

<< Soka Performing Arts Center Opening Series >>

On September 17, 2011, Orange County's Pacific Symphony performed the center's inaugural concert in the Main Hall. The program included Adam's challenging "Short Ride in a Fast Machine", Rachmaninoff's Piano Concerto No. 2 in C Minor, Op. 18, Prokofiev's Suite from Romeo and Juliet and Ravel's Suite No. 2 from Daphnis and Chloe. The Pacific Symphony, Maestro Carl St. Clair and pianist Horacio Gutierrez performed each work superbly and with gusto.

The hall's opening series of performances continued in the Main Hall with a Polynesian and Micronesian dance performance on October 23 and the first concert of a jazz festival on October 28. Next year, the Pacific Symphony will return for its second concert and Emanuel Ax is scheduled to perform a piano recital.

This year marks the 10th anniversary of the university's establishment of its Orange County campus, located about an hour's drive south of Los Angeles. When the opportunity arises, please pay a visit to the campus and its wonderful new Soka Performing Arts Center. The Soka Performing Arts Center page of the school's Web site can be accessed at http://www.soka.edu/about_soka/our_campus/Soka-Performing-Arts-Center.aspx.

Symposium by Editors in Chief of World Architecture Magazines held at Nihonbashi Mitsui Hall

By Chiaki Ishiwata

UIA 2011 Symposium by Editors in Chief of World Architecture Magazines
UIA 2011 Symposium
by Editors in Chief of World Architecture Magazines

In late September, 2011, the World Congress of Architecture convened in Tokyo. The International Union of Architects (UIA) organizes this event in a different country once every three years. This year, participants in the UIA's 24th Congress gathered in Tokyo, primarily at Tokyo International Forum in Tokyo's Marunouchi district, and also in a few other locations, including Nihonbashi Mitsui Hall, where the Symposium by Editors in Chief of World Architecture Magazines session met.

For the symposium, the editors-in-chief of France's L'Architecture d'Aujourd'hui, Italy's Domus, the UK's The Architecture Review, the USA's Architectural Record and Japan's Nikkei Architecture participated. Each editor gave an overview of his or her publication and spoke about recent trends, after which they participated together in a panel discussion moderated by Japanese architect Tetsuo Furuichi.

While Nikkei Architecture's editor presented his magazine as a publication engaged primarily in news reporting, the participants from magazines outside Japan presented a different emphasis. Some of the magazines began publishing more than 100 years ago and the editors of these magazines, as well as the editors of the other non-Japanese magazines, discussed their publications' responsibility to disseminate and support the understanding of architecture as a cultural and art form.

floor with both roll-away tiered seating and stackable chairs
with both roll-away tiered seating and stackable chairs

The flat floor without seating
The flat floor without seating

<< Nihonbashi Mitsui Hall >>

Reviewing the symposium gives me the opportunity to also introduce readers to the symposium's Nihonbashi Mitsui Hall venue, which is located on several intermediate floors of a 22-story commercial and retail tower named COREDO Muromachi, the first completed project of the Nihonbashi Eastern District's Revitalization Plan. COREDO celebrated the one-year anniversary of its opening this November, 2011. Nihon Sekkei served as the architect for the entire project and Architectural & Urban Design Inc. (of Tokyo, Japan) designed Nihonbashi Mitsui Hall. Nagata Acoustics was the acoustical consultant and provided both the hall's room acoustical and sound isolation designs.

This hall has a box-like shape with a flat floor, roll-away tiered seating and stackable chairs. The hall accommodates a maximum of 1,000 people (depending on its layout configuration). Its programming anticipates many diverse uses from exhibitions, parties and business gatherings to popular music concerts.

Because the floors above and below the hall are used for shops and offices, we aimed to design this hall to be acoustically separate from other floors of the building. To this end, we adopted an anti-vibration and sound isolating structural design that achieved excellent sound isolation performance. Also, because most events in the hall will use electrically amplified sound, we controlled the room's reverberation by placing ribbing and glass wool elements on interior surfaces in strategically selected locations throughout the hall.

The hall's interior uses a stylish color palette that creates an appropriate atmosphere for business and professional gatherings and other events targeted at adults. The magazine editors' symposium included simultaneous language interpretation using two interpretation booths, demonstrating one example of the flexible layouts that are possible in this hall.

Nihonbashi Mitusi Hall offers direct indoor access to multiple subway lines, making it a convenient choice as the venue for a range of events and occasions. More information about this venue and its various layouts, support rooms and other features can be found at the hall's website.

My Retrospective on Building 1/10 Acoustical Scale Models - Part 1

By Nobuyuki Ebihara

Editor's introduction: One indispensable tool of acoustical room design is the 1/10 scale model (often mentioned in Nagata Acoustics' newsletter articles). On large-scale concert hall and theatre projects, we use the hybrid technologies of computer simulations and testing in a 1/10 scale model to achieve a high level of precision for the sound characteristics that will be realized by our acoustical room designs. Master carpenter Nobuyuki Ebihara has constructed many of the 1/10 scale models we've used on our projects. In this and future articles, he will share reminiscences of this work.

<< The Precision of Sukiya Tea House Carpentry Applied to 1/10 Acoustical Scale Model Construction >>

For more than 20 years I've been applying my carpentry skills to the construction of 1/10 scale models for acoustical testing. These years have passed quickly and, until now, with barely a moment to reflect on my work. Until just before I reached the age of 30, I worked 100% of the time as a carpenter of sukiya-zukuri structures, which are primarily used for the tea ceremony. Around the time that the demand for this kind of construction entered a period of clear decline, I was offered the opportunity to build my first 1/10 scale model.

People not in the building trades may think that all carpentry requires the same set of skills, but many distinct specialties comprise this craft. If a company needs to find a craftsman to build their projects' 1/10 scale models, the first difficult decision is likely to be figuring out what kind of carpenter is right for the job.

I am not a "career" builder of 1/10 scale models. There simply are not enough 1/10 scale models that need to be built for them to become a carpenter's only specialty. Probably, Nagata Acoustics first entrusted me with this work because they decided that a person who makes his livelihood building intensely precise, exposed-carpentry, sukiya-zukuri tea ceremony rooms would somehow get the work done right. Now I've built more than 20 1/10 scale models for acoustical testing needs.

<<My First 1/10 Scale Model (April - Sept., 1988) for Tokyo Metropolitan Theatre Main Hall >>

The first time I saw the specification drawings for a concert hall, I literally felt my whole insides fill with misgivings about my ability to build what my eyes saw on the papers set before me. Even though the amount of complexity in a 1/10 scale model and the intricate level of detail required may be similar to that of a sukiya-zukuri structure, the nature of the work to precisely and delicately transform stone and whole timber logs into tea ceremony rooms is entirely different from what a 1/10 scale model needs. A 1/10 scale model simply requires precision.

When I worked on my first 1/10 scale model, I had not yet figured out the process I use now of forming the individual parts of the model in an off-site shop and then assembling them at the 1/10 scale model job site. Instead, I sawed and cut and finished each piece and assembled the model all at the job site. Each time this piece or that piece didn't fit quite right, I would talk to the person in charge of the specification drawing and he would go check the dimensions of the planned theatre, and then I would recalculate the dimensions for that piece of the 1/10 scale model... When I think back to that project, it is hard to believe how much time I spent getting everything right. Apparently, framing the full-size building of that project was also very challenging and the construction crew needed about 3,305 sq.m.(35,583 sq.ft.) around the building in order to raise the frame.

Prof. Yoshinobu Ashihara of Ashihara Architect & Associates was the project architect and Nagata Acoustics was the acoustical consultant on that project. To me, both of these names represented professional luminaries with whom I had no direct conversations. One day while I was building the 1/10 scale model, I learned that Prof. Ashihara would be coming to see it. I spent all morning cleaning up around the scale model and I and my helpers left the site before Prof. Ashihara arrived. After his visit, someone told me that Prof. Ashihara came with his lunch, went inside the 1/10 scale model and stayed shut up inside it for quite a while. I remember thinking that professionals with illustrious reputations do things ordinary people would never think of doing and I was greatly impressed.

The summer of 1988, when I built this 1/10 scale model, was terribly hot. I worked on the 1/10 scale model in a little prefab structure erected in a corner of the project site in Ikebukuro. The prefab structure was windowless and I felt like I was in an oven all day long. Right near this part of the site construction workers were incessantly driving piles into the ground and the noise and vibration from this work caused the little prefab structure to constantly shake a bit. In that sorry environment I somehow focused intently on the work of building the 1/10 scale model. Maybe it was youthful exuberance that made this possible.

The year 1988 was before the proliferation of PCs and cell phones. The 200-page design specification was entirely hand drawn and if I needed to ask or report about something, my only option was to walk all the way across the project site to the office in a trailer at the other end of the property. Compared with the pace of today's construction projects, people seemed more relaxed and I enjoyed the warm feeling of shared purpose that flowed among the many different people and trades who were building the theatre.

At the time, I did not think about the meaning or value of the 1/10 scale model to the overall project. I devoted all my energy and care simply to making the 1/10 scale model for acoustical testing as detailed and accurate as could possibly be.

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

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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 ]