Quietness, Comfortable Sound and Excellent Acoustics NAGATA ACOUSTICS

News 10-08 (No.272)

Issued : August 25, 2010

[ Japanese Version ]

Kariya City Cultural Center Project Completes

By Makoto Ino and Akira Ono

Kariya City Cultural Center exterior seen at night
Kariya City Cultural Center exterior seen at night

Kariya City Cultural Center(2nd floor shown with B1F inside dotted line)
Kariya City Cultural Center
(2nd floor shown with B1F inside dotted line)

Aichi Prefecture's Kariya City is an industrial city and home to major automotive parts and components manufacturers and suppliers, such as Toyota Boshoku, Toyota Industries, Aishin Seiki and Denso Corporation. Near the south entrance of the city's main Kariya Train Station, the recently completed, multiuse Kariya Cultural Center adds an inviting, 21st century shopping and cultural destination, housing and commercial space to the center of this city. The new complex's name of "Minakuru Kariya"means "Everyone come to Kariya", and the cultural center'a name of "Iris" evokes the pretty image of Aichi Prefecture's official flower of the same name.

The mostly government-owned Urban Renaissance Agency created the master plan for Minakuru Kariya and determined the mix of shopping, other commercial, residential and public-use space. In April 2010, the anchoring "Iris" cultural center opened.

The project's master plan also included a redesign and improvements to the streets and plaza at the south entrance of Kariya Station. A new pedestrian deck now connects the new shopping center and Kariya Cultural Center to the station entrance, improving the ease of access and revitalizing the neighborhood adjacent to the train station's south entrance.

Tohata Architects & Engineers created Kariya Cultural Center's architectural design. Takenaka Corporation served as the project's general contractor. Kayaba System Machinery built the center's stages, Panasonic Electric Works was responsible for the lighting and Yamaha Sound Systems, Inc. installed the sound system. Nagata Acoustics provided acoustical consulting services that included room acoustical design, sound isolation design and sound system design as well as project oversight for the cultural center's two halls.

<< Overview of the Center's Rooms and Uses >>

Kariya Cultural Center's programming focused on two key objectives: space for artistic and cultural activities, and space for lifelong learning opportunities. Both goals incorporate the overarching aim of a community setting where Kariya's residents can both pursue these interests and simply "hang out" with other residents.

The center's main music facilities include the 1,541-seat large hall, which has a proscenium-style stage and the 282-seat small hall, which has a flat floor and movable, stadium-style seating. In addition, the center has one large and one small rehearsal room, four music practice rooms, and a recording studio. For residents interested in other arts, crafts and learning activities, the hall provides an exhibition gallery, a ceramic crafts studio, a kitchen for the culinary arts and rooms intended for lectures and individual study. This broad diversity of artistic, cultural and learning spaces satisfies the project's aim of developing a comprehensive cultural facility for the entire community.

<< Sound Isolation Design >>

To enable the large and small halls to be used simultaneously, in the structural design of the portion of the building between the two halls, we specified the use of expansion joints, starting with the first floor and continuing to the second floor. We located the 2 rehearsal rooms, 4 music practice rooms and recording studio (a total of 7 music-related rooms) on the basement level below the the large hall and Center's foyer. For each of these rooms, we implemented an anti-vibration, sound-isolating structural design using anti-vibration rubber material. Several of these rooms have large windows facing the interior corridor and for these windows we specified double-paned 12 mm.-thick glass for the floating panes of the windows and double-paned 8 mm.-thick glass for the fixed panes.

As a result of these sound isolation measures, we obtained effective sound isolation between the two halls, even for very loud sound volumes. When sounds of every octave band are generated at nearly 110 dB in the large hall, they cannot be detected in the small hall by the human ear. In addition, because multiple doors of the large and small halls open into the same corridor, we anticipated the likelihood of situations in which only one door of each set of double doors would be kept closed and we tested the sound isolation for large sound volumes in the large hall under these conditions. Our tests confirmed that the sound generated in the large hall cannot be heard in the small hall by the human ear if at least one set of doors is closed. These favorable sound isolating results can reasonably be attributed to the effectiveness of the expansion joints in preventing the transfer of solid-borne sound, especially with regard to isolating lower octave sounds.

Between the rehearsal and practice rooms and the main hall we achieved effective sound isolation performance even for sounds louder than 85 dB (at 500 Hz). As a result, sounds generated in the rehearsal and practice rooms will not be able to be heard in the large hall.

Large Hall
Large Hall

<< The Large Hall's Room Acoustical Design >>

In the large hall, this project prioritized the requirement of optimal sight lines from all audience seats to the stage. The hall's room design achiveves this objective by having a generously wide dimension from stage right to stage left and a single balcony level that forms a horseshoe shape around the first floor audience seating.

For the fundamental approach of our room acoustical strategy, we designed the walls at the front of the balcony sections and the eaves of the balcony's overhang portions so that early sound reflections propagate from these surfaces to the seats in the center part of the hall's main audience seating area. The hall's architectural design located 3 tiers of lighting grids along the walls adjacent to the left and right sides of the stage. We specified the installation of reinforced concrete slabs for each tier, providing both sure footing for the stage lighting technicians and, most importantly from the room acoustics perspective, also creating sound-reflecting structures at the right and left sides of the stage opening.

The architect extended the light-colored concrete slabs as a visual element of the large hall's sidewalls, making them a key element of the hall's interior design. We made use of this design element to increase the broad delivery of sound reflections to the audience seating areas by specifying along each concrete slab extension an eave-like, subtly protruding edge that reflects sound to the audience seating. Also, in addition to the sound-reflecting concrete, eave-like structures on the hall's sidewalls, we installed random-width, randomly-spaced vertical ribbing along both sidewalls to promote sound diffusion.

The large hall's estimated reverberation time measures 1.8 seconds (at 500 Hz and with full occupancy) with the stage reflection panels set in place. When configured with the proscenium stage curtain, and under the same stated conditions, the large hall's estimated reverberation time measures 1.4 seconds.

Small Hall (configured with sound reflection panels)
Small Hall
(configured with sound reflection panels)

<< The Small Hall's Room Acoustical Design >>

In the small hall, we provided sound reflection panels that, when set in place, create the unitary space of a concert hall environment. We used wallboard materials for the entire ceiling above the audience seating area, because this material has beneficial sound isolation properties. Below the ceiling panels, we suspended four batons intended primarily to hang lighting for drama performances. Also below the overall layer of ceiling panels, we affixed curved sections of wallboard to prevent the occurrence of flutter echoes when the hall is configured as a flat-floor auditorium.

In the rear half of the hall (alongside the stadium seating), near where the sidewalls meet the ceiling, we specified the installation of angled surfaces that direct sound reflections towards the audience seats in the flat-floored part of the hall (between the bank of stadium seating and the stage). We allowed the lower portions of the sidewalls to be built parallel to each other and, to both promote sound diffusion and prevent the occurrence of undesirable sound phenomena that can result from parallel wall surfaces, we installed interior wood sidewall surfaces with ribbing of random depths and periodicity.

The small hall has an estimated reverberation time of 1.3 seconds (at 500 Hz) when configured with its sound reflection panels. When configured with a stage curtain, the estimated reverberation time is 0.8 seconds (at 500 Hz).

A concert in the lobby
A concert in the lobby

<< The Large Hall's Sound System >>

In recent years, the adoption of sound systems that use digital signal processing technology has grown so rapidly that it is now the norm. The sound system in the Kariya City Cultural Center Large Hall continues this trend. The sound system we designed uses digital sound processing from the output of the microphones in the rack at the side of the stage to the integrated multiprocessor (with its equalizer, delay and dynamics settings) that feeds the powered amplifier.

We specified 4-way loudspeakers for the large hall's main loudspeakers and located them at three locations: at the center of the proscenium and at each side of the stage. In addition to the main speakers, we installed speakers for sound effects and speakers for communciations use among the technical staff and stage crew.

In the days since Kariya Cultural Center opened, the residents of the city have been given many opportunities to enjoy a range of commemorative events, including lectures, concerts and programming for children. A quick glance at the center's events Web page shows a calendar full of variety and fun for many ages and interests. In this town with a strong automotive industry history, Kariya Cultural Center "Iris" will surely add a new, culturally focus for the community to enjoy and foster. The center's main Internet page can be found at http://www.kariya.hall-info.jp/pc/index.html

Katowice Concert Hall Room Acoustical Design

By Yasuhisa Toyota

Rendering of the winning design for the exterior of Katowice Hall
Rendering of the winning design
for the exterior of Katowice Hall"

Rendering of the Katowice Hall interior, as of the completion of design development
Rendering of the Katowice Hall interior,
as of the completion of design development

Katowice City, located in Poland's Silesia region, is a major regional city with a population of more than 300,000 people. The city's environs boast rich coal deposits and the city has a long history of industrial development.

In the environmentally unregulated decades following the end of World War II, the industrial activity in and around Katowice City led to environmental pollution levels that in turn caused serious social and other problems. However, after the 1989 revolutions in Eastern Europe and the collapse of communism, the government began to both care for the local environment and focus its energies on educational and cultural initiatives.

Poland's public radio broadcaster, Polskiego Radia (Polish Radio) maintains offices and studios in Katowice. The broadcaster's associated orchestra, Narodowa Orkeistra Symfoniczna Polskiego Radia - NOSPR (National Symphony Orchestra of the Polish Radio) ranks alongside the Warsaw National Philharmonic Orchestra as one of the country's two highly valued national symphony orchestras.

<< Architect and Acoustical Consultant Selection Processes >>

In 2008, planning began to develop a home hall for the National Polish Radio Symphony Orchestra. From its inception, the hall was conceived as a classical music concert hall and its size was to be about 1,800 seats. An international architectural competition launched in the same year of 2008 selected the local architectural firm of Konior Studio, Tomasz Konior, Principal. The architectural rendering of the hall exterior shown with this article depicts the competition's winning design.

World renowned pianist Krystian Zimerman, who was born just 15 km. from Katowice in the southern Polish town of Zabreze, recommended that Nagata Acoustics be selected as the project's Acoustical Consultant. The selection decision-makers accepted his recommendation and we received the invitation to serve in this capacity.

<< Katowice Hall Project Progress and the 1/10 Scale Model >>

Katowice Hall 1/10 scale model
Katowice Hall 1/10 scale model

The design phase of the Katowice Hall project began in September, 2009. Currently, the project has completed its design development and entered the phase of developing the construction documents.

Originally, the architectural competition's winning design included a standard shoebox-shape configuration for the hall interior. During our collaboration on the actual project design development, the team increasingly added seats around the stage so that the hall's interior configuration now more closely resembles an arena configuration. This design evolution reflects the high priority this project places on creating an environment that will enhance the sense of intimacy between the performers and the audience. The rendering of the hall interior accompanying this article shows the design at the completion of the design development phase.

In parallel with the development of the construction documents, Nagata Acoustics began building a 1/10 scale model of the hall. This model is now nearing completion, as can be seen in the recent photo of the model. Because this hall's interior has many curved surfaces and a complex geometry, the 1/10 model is an essential tool for us to use in detecting and preventing echoes.

The Katowice Hall project plans to start construction in 2011. The project is expected to complete in 2013, and the many participants in this endeavor look forward to opening Katowice Hall in the same year.


Music Producer Michio Takemori's Visit with Nagata Acoustics

By Akira Ono

On Monday, June 7, 2010, music producer Michio Takemori visited Nagata Acoustics for several hours of conversation with us about his decades of involvement in Japan's classical music world. In this article, I will summarize the stories and observations he shared.

<< Mr. Takemori and Maestro Gergiev >>

When Mr. Takemori graduated from university, he joined NHK, the Japan Broadcasting Corporation, where he pursued a career focused on music programs and events. While serving as Chief Producer at NHK, Mr. Takemori traveled to Russia's St. Petersburg to record a show about the Kirov Opera and met the then still relatively unknown conductor Valery Gergiev, launching a friendshiop that now spans decades.

Mr. Takemori's broadcast about the Kirov Opera and Maestro Gergiev became the catalyst for the genius of Maestro Gergiev's conducting to become introduced to the countries of western Europe. Thereafter, as changes in the political situation made possible expanded opportunities, Maestro Gergiev became a world-travelling artist. Today, he is considered the world's busiest and most sought after orchestra conductor.

Maestro Gergiev's popularity of course extends to Japan, where he has toured repeatedly. Despite his heavy schedule, when Maestro Gergiev visits Japan, Mr. Takemori says that the maestro often visits him at his home, an indication of Maestro Gergiev's appreciation for the role that Mr. Takemori played in launching Maestro Gergiev's international career. According to Mr. Takemori, Maestro Gergiev has a strong sense of "giri" (a Japanese term that can only be approximated by such translations as "obligation", "duty" and "loyalty").

This writer recalls one episode when Mr. Takemori expected a visit from Maestro Gergiev and suggested that I also come to Mr. Takemori's home, which I did. Some dried Japanese soba noodles had been put out in preparation for being cooked in a pot. Meastro Gergiev picked up one of the stiff, long pieces of noodle, closed his eyes and began conducting something in the air. I remember feeling spellbound as I watched Maestro Gergiev conducting his imaginary orchestra.

<< Mr. Takemori's Years with the NHK Symphony Orchestra and NHK Hall >>

After his work as Chief Producer, Mr. Takemori took an assignment with the NHK Symphony Orchestra. At the time, the orchestra played all its concerts at NHK Hall in Tokyo's Shibuya Ward. The enormous NHK Hall has 4,000 seats. The hall has served as the venue for everything from classical music concerts and opera, to ballet and popular music extravaganzas, and it has the equipment setup of a fully functionaing broadcast studio, making it a kind of extreme implemention of the multipurpose hall concept.

When Mr. Takamori began his assignment with the NHK Symphony Orchestra, NHK Hall had a very negative reputation as a classical music venue. The overall acoustics were considered mediocre and pianissimo playing could not be heard by much of the audience.

Mr. Takemori gave considerable thought to how he could improve the appeal of the NHK Symphony Orchestra. He asked himself if there was a better way to project the orchestra's sound to the audience and whether changing the location of the orchestra members' seating on the stage would make a difference. With the consent of the orchestra's then chief conductor, Maestro Charles Dutoit, Mr. Takemori began a trial-and-error process of changing the locations of various sections of the orchestra, the heights of the risers used and even the placement of the entire orchestra on the stage.

As a result of trying different configurations for the orchestra, Mr. Takemori devised an arrangement that uses staggered risers for all of the ensemble's sections, including the strings and also uses part of the 3 sections of the orchestra pit. The arrangement raises 2 of the 3 orchestra pit sections to the height of the stage and brings the entire orchestra forward onto these sections so that the orchestra protrudes into the audience seating area.

However, the hall's administration had previously put a hole in the overhead stage reflection panels to accommodate a recording microphone, with the hole's placement based on the orchestra's original on-stage seating arrangment. Other equipment setups and installations had also been determined based on the the orchestra's original seating arrangment and these existing facilities led to some resistance to the implementation of Mr. Takemori's proposal. Mr. Takemori successfully resolved all of these obstacles, adopted the new seating arrangmeent and significantly improved the audience experience during the NHK Symphony Orchestra's concerts in this hall. The configuration Mr. Takemori conceived continues to be the orchestra's standard seating arrangement for not only the subscription concerts but for such as Berliner Philharmoniker Orchestra at NHK Hall to this day.

<< Mr. Takemori's Current Work >>

Today, Mr. Takemori actively pursues his music production work. In 2009, he produced Stockhausen's "Gruppen" for the Suntory Hall Summer Music Festival. (We featured this concert in our July, 2009 and September, 2009 newsletters.) Because"Gruppen" requires 3 full orchestras, this massive production is rarely performed. Mr.Takemori's planning expertise and experience as a producer enabled him to successfully stage the "Gruppen" concert, giving the NHK Symphony Orchestra the opportunity to perform this challenging composition and Tokyo music lovers the chance to enjoy it.

We enjoyed hosting Mr. Takemori at Nagata Acoustics and the opportunity to hear some of the many fascinating experiences of his music producing career. We wish him continued success for many years to come.

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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2130 Sawtelle Blvd., Suite 308
Los Angeles, CA 90025, U.S.A.
Tel: +1-310-231-7878, Fax: +1-310-231-7816

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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 ]