Title means "Quietness", "Comfortable Sound" and "Excellent Acoustics"

Nagata Acoustics News 99-2iNo.134j
Issued : February 25, 1999

Ota-kumin Hall "APRICO" (Art Prism in the City of Ota)

by Akira Ono

Plan of the Apricot Hall
Tokyo is well known for ubiquitous railway and subway lines that crisscross the city. In the West, Tokyo's trains have a infamous reputation created by news clips of rush-hour riders packed into trains like sardines. But in Japan, the names of many Tokyo train stations are intimately tied to memories of the blossoming of modern Japanese pop culture in prewar Japan. The JR Keihin Tohoku Line's Kamata Station is one of those Tokyo Stations that is forever immortalized in Japanese literature, cinema, and song. Now, Kamata has a new hall where all kinds of cultural activities will have a place to blossom.

<< History of the Apricot Hall Site >>

At Kamata Station, a special chime warns passengers when the doors of a departing train are about to close. The chime's famous melody comes from the famous Japanese movie Kamata Koshinkyoku ("The Kamata March"), based on the Naoki Award winning novel of the same name, written by Kohei Tsuka. In the 1920s, Kamata was the site of the Shochiku Movie Company's studios--in effect, the Hollywood of Japan. When songwriter Keizo Horiuchi wrote the words to Kamata Koshinkyoku's songs, he captured the tinsel feel of the Kamata of the period as "Kamata in the springtime, Kamata--where the flowers bloom, Kamata--capitol of the silver screen." Other Japanese movies, including Kinema no Tenshi ("Cinema's Angels", Yoji Yamada, director), also immortalized the glittery renaissance atmosphere in Kamata during movies' golden age in Japan.

I have heard that the original meaning of the Japanese word "kamata" was related to "triangular." It supposedly meant the triangular-shaped land area of a river delta. Ota-ku's Kamata area has precisely this geography, being located at the delta of Tokyo's Tama River. When the movie studios were located here, Kamata was a symbolic delta as well, as increasing numbers of people flowed into the neighborhood.

In 1936, Shochiku moved its studios to the Tokyo suburb of Ofuna, and the perfume manufacturer Takasago Koryo Kogyo acquired the land that the movie makers left behind. The company manufactured perfumes in Kamata both before and after World War II. Kamata grew economically and became home to a melange of commercial and industrial companies until, eventually, strict zoning regulations pushed the manufacturers out. Even Takasago Koryo Kogyo eventually moved to a less urban location.

<< Private and Public Sectors Join Hands to Create a New Era >>

Several years ago, talks began about how to redevelop the available land near Kamata Station. The local Ota Ward government and private sector owners of land adjacent to public properties devised an agreement for the joint development of public and private-use facilities. Together, they formulated the Kamata Station Area Redevelopment Plan.

Initially, the redevelopment plan design called for two privately owned office towers and an adjacent publicly-owned community cultural center that would include a multipurpose hall. Then, Japan's economy collapsed into recession and the private sector portions of the redevelopment plan needed to be reworked as wide fluctuations in Japan's economy rocked the redevelopment plan to its very foundations. Thanks to the dedicated efforts of everyone involved in the project, the Kamata Station Area Redevelopment Plan successfully reached completion in October 1998.

In recognition of Kamata's historical roots as the location of a perfume manufacturer, the entire redevelopment area was named Aroma Square. Had Shochiku not moved out in 1936, I wonder if today's facility might rather have been named Cinema Square.

<< Overview of Ota-kumin Hall >>

Interior View of the Large Hall
The overall planning and design responsibilities for the entire redevelopment project were managed by the major general contracting firm, Shimizu Kensetsu. Shimizu Kensetsu also performed the program management and project management functions for the private sector office tower. Yamashita Sekkei was responsible for the program management and project management of the public-sector facilities. A joint venture consortium of Shimizu Kensetsu and four other contractors oversaw on-site construction. Nagata Acoustics served as the acoustical engineering consultant from the design stage through to completion.

The Ota-kumin Hall is a multipurpose facility with a large hall (1,477 seats), a small hall (170 movable seats), an exhibition hall, two studios, and ancillary rooms. The design of the large hall uses a shoebox configuration to create a multipurpose hall with the emphasis on musical performances. It is equipped with a set of four-part, sliding reflection panels.

The large hall's audience seating includes a balcony. However, unlike traditional shoebox configuration balconies, the side portions of the balcony are inclined toward the stage so as to maximize the sight lines of these seats. Consequently, nearly all of the hall's seats provide a full view of the hall's stage.

Section of the Small Hall
The small hall has level flooring and is located on the first underground level of the building. In order to provide effective sound isolation between the small hall and the large hall nearby, as well as between the small hall and the exhibition hall, we adopted a floating sound isolation structure for the small hall.

The small hall and the exhibition hall share a wall designed to allow the two halls to be used together as one larger space. Since the wall dividing the small hall and exhibition hall is removable, we devised a double layer of manually deployable walls to provide fixed sound isolation between these two rooms, and we installed floating sound isolation with a wall that is raised and lowered electrically.

The small hall faces onto an exterior sunken garden, and the wall facing the garden is made entirely of glass. Anticipating that the garden area outside the small hall will be used as an open-air stage, the small hall is designed so that it can be used as a satellite studio for such outdoor events and performances. We used embedded frames for the small hall's windows to soundproof it from unwanted garden noise. Because the hall has a floating sound isolation structure and is equipped with manually operated dividing walls, the hall can be isolated from exterior light and sound by deploying the manually operated room dividers. When all of the dividing walls are deployed, including the wall dividing the small hall and exhibition hall, the small hall becomes a box-in-box structure.

<< Apricot Hall's Program Planning and Management >>

While the new facility officially goes by the name " Ota-kumin Hall," it has also been given the nickname "APRICO." The flower of the ume ("Japanese apricot")fruit tree is Ota Ward's official flower, and Apricot is also an acronym for "Art Prism in the City of Ota." The name " APRICO " is also said to have been chosen because the hall is like a prism of culture and the arts that will create many colored "blossoms" to enrich the community.

The new facility is operated and managed by the Ota Ward Culture Promotion Association, a non-profit foundation. The same two individuals who represented the Association during the design and construction of the project, Mr. Yuki and Mr. Norii, are now dedicating themselves with enthusiasm to managing the facility's programming, activities, and daily operations.

Public halls everywhere face the same challenge of limited economic resources. Apricot Hall's management hit on the idea of a College Orchestra Festival and has contacted numerous college and university orchestras, offering them the use of the new hall as both rehearsal and performance space. Compared with staging a concert of professionals, this approach is not only low cost, but will also develop an affinity for the hall among young music lovers, as well as bring vitality and an upbeat atmosphere to the hall. The College Orchestra Festival is a plan worthy of becoming a regularly-held event. I certainly hope that it comes to fruition.

APRICO has also planned an excellent lineup of events to inaugurate the hall, including classical music concerts, musicals, ballet performances, film showings and more. However, because of the public nature of the hall's funding, publicity about the hall and its events is only disseminated in Ota Ward and its environs, making APRICO a somewhat hidden jewel among the cultural and artistic life of Tokyo. For example, violinist Mischa Maisky will perform a recital on Thursday, March 11. "S"-seat tickets are only 7,000 yen, while virtually the same program, on a different day, costs 12,000 yen at Suntory Hall. The hall concert seems like a bargain to me, yet as of this writing, tickets for the March 11 concert were not sold out.

For more information about Ota-kumin Community Hall " APRICO," call the hall office at +81-3-5744-1600.

Concert Halls and Sound Systems: Concluding Remarks on our Article Series

by Dr. Minoru Nagata

Sound system design is one of Nagata Acoustics Inc.'s areas of expertise. However, it differs from our room acoustical design and noise isolation and control design practices because of how it is regarded within the entire construction design process, the content of the work, and the manner in which the work progresses. While the fundamental function of sound system design of a concert hall is to provide means for speech to be heard clearly throughout the hall, there are many other and diverse capabilities and characteristics that may be desired in a sound system. The capabilities and characteristics that are needed or desired cannot be determined objectively through electro-acoustical measurements. Rather, sound systems have at their core the system design of speakers and mixing equipment, and the selection of these and other equipment, the system setup, and how the equipment will be used tends to be heavily influenced by the preferences of the hall's on-site technical staff. In addition to these factors, as we discussed in the third article of the series (available in our January 1999 News & Opinions), large scale speakers look out of place in hall interiors, especially when the hall is intended for the performance of classical music. All of these factors set sound system design apart from our other acoustical consulting work.

<< Historical Background of Sound System in Japanese Hall >>

As explained in the first article in our series on Sound System (available in our November 1998 News & Opinions), in Japan, sound system design began as part of the stage equipment design for the multipurpose halls constructed in the 1950s and 1960s. The impetus for these Sound System came from pop music and its aim of increasing a hall's sound volume. In reality, these early sound systems were often an undefined hodgepodge of equipment, conveniently labeled "multipurpose."

Among the halls built in Japan during the past two decades, three distinct categories of halls have emerged: large capacity multipurpose halls; concert halls; and opera houses. Unlike the sponsors of the early Japanese multipurpose halls, recently constructed Japanese concert halls and opera houses demand that their Sound System be designed with clearly defined characteristics, functionalities, and quality of sound.

Two years ago, when I attended a committee meeting about the design of the new Japanese National Theater (in Tokyo), one opera producer asked, in a censorious tone of voice, why such a large-scale sound system as we had proposed was needed in an opera house. If this question is still raised about opera houses, where the use of special sound effects should help explain the need for a state-of-the-art sound system, it is no wonder that the general public should doubt the value of installing a quality sound system in concert halls intended for the performance of non-amplified music.

In reply to these classical music fans, I suggest they consider the pre-concert talks by performers, musicologists, and others that are so popular with concert goers. I am sure that many concert goers have experienced with surprise how difficult it can be to hear the speech of persons addressing them from a concert hall stage, especially when the concert hall has a reputation for excellent acoustics! In actuality, it is no easy feat to offer a high level of speech clarity in halls having rich reverberation times and otherwise excellent acoustics.

At the time that I was writing this article, I attended a baroque music concert at a regional concert hall in which the program combined a staged reading with harpsichord. First, a spokesperson introduced the program without a microphone. It was difficult to hear him, and almost impossible when he faced sideways or turned his back to the audience. The staged reading also began without the use of a microphone, but a mike was added in the middle of the performance. Someone had probably complained. While this hall prides itself on offering high quality programming planned by the hall itself, in this instance, the hall did not pay sufficient attention to ensuring that one of the most essential features of the performance-the spoken word-would be heard with clarity by the audience.

<< A Summary of the Issues in Concert Hall Sound System >>

For amplified speech, clarity varies greatly depending on whether a hall is occupied or empty, as well as on where one listens in the hall. The variance is much greater than the differences one may hear in how music sounds in an empty or full hall, or in different sections of the audience. The fundamental purpose of a concert hall's sound system is to ensure that staged readings and other speech spoken from the stage reach each and every audience seat in a manner that is clearly audible and can be listened to with ease. In the case of the recent baroque music performance, someone connected with the event should have confirmed this capability during the rehearsals.

In order to obtain clear, easily understood speech, the most highly valued characteristic of a concert hall-its rich reverberation time-must be dampened and the level of direct sounds increased. In high-ceilinged concert halls, the most prevalent means of accomplishing this has been to control each speaker's directivity, so that it covers only a portion of the audience, increasing the level of direct sound reaching those seats.

<< Directional Speaker Clusters >>

Controlling the directionality of loudspeakers is a major concern of sound system. In multipurpose halls, clusters of horn-shaped speakers composed of diferent directivity have been the standard method of ensuring full coverage to every audience seat. The sound systems of many concert halls also use the kind of speaker system. However, as we discussed in our first article in this series, there is a certain ambiguity associated with speakers' directionality. In addition, two other problems connected with the use of unnatural sound quality of the speakers having constant directtivity are now found out. Makoto Ino, one of our sound system specialists, pointed out these problems in our series' second article. In this article, he discussed both the problem of distortion from the horns of speakers designed primarily for their directionality, and the artificial quality of amplified sound in the parts of the audience where the sound of two directionally specific speakers overlap.

<< Distributed Speaker Placement >>

In addressing these problems, Nagata & Associates' currently leans towards the alternative approach of distributed speaker placement design. We successfully used this methodology for the Beacon Convention Center, completed in March 1995, in Japan's Beppu City, in Oita Prefecture. The size of this multipurpose facility is 100,000 m3 and can accommodate up to 8,000 people. In designing the sound system for this facility, we bypassed the conventional cluster-type speaker system. Instead, we devised a distributed placement design of 112 speakers suspended from 56 different ceiling locations. (For more information on the Beacon Plaza Convention Center Project, please see our July 1995 News & Opinions.) The clarity and ease of listening that we achieved for amplified speech in this facility greatly surpasses the sound quality experienced in previous spaces of similarly large size. I have personally experienced and verified the excellent sound quality at Beacon Plaza Convention Center.

The difficulty that arises in halls that implement distributed speaker placement is the inability to get source localization to the amplified speech. Depending on the event or performance, the ability to produce the natural sound source localization may be considered an important capability of a hall's sound system equipment. Yet, if an system designer were to try to give equal weight to both clarity and source localization, a very complex system would certainly be required. At Nagata & Associates, it is our opinion that the foremost raison d'etre of a concert hall's sound system equipment should be to produce clear speech that audiences can listen to with ease.

<< New Functionalities for Contemporary Music >>

There are situations in which Sound System need to be able to respond to requests for new capabilities: this is when the score of a contemporary composer places novel demands on a hall's sound system. In responding to the needs of contemporary music composers and performers, the key is to design an system with the versatility to adapt quickly and easily to the unanticipated demands of contemporary composers and musicians.

In Ino's article, he described the extra efforts and labor of the person in charge of the on-site speaker setup for a contemporary music concert at Opera City's Takemitsu Hall, in Tokyo, this past September. For this performance, the sound system needed to accommodate very quiet percussion, that is, the unanticipated request was for a delicate sound quality. This was a capability that had not been considered in traditional thinking about sound system equipment, which had always focused on requests for louder and louder sound.

<< More Time Needed for Fine-tuning >>

Until now, the testing of newly installed Sound System was mostly perfunctory. After the completion of construction and the installation of the sound system, a test CD would be played and the quality of the amplified sound would simply be confirmed through direct listening. By contrast, when a pipe organ is installed in a concert hall, time is reserved not only to tune the organ, but to adjust the organ and its new surroundings to each other, called voicing. Typically, three-to-six months are scheduled for this purpose. From an acoustician's perspective, we would much like to develop greater understanding on the part of architects and construction contractors regarding the importance of scheduling time to fine tune sound system equipment during the final stage of a project. The need for a period in which adjustments can be made is particularly crucial when a distributed placement speaker system is installed. I have experienced many projects in which the initial sound of a distributed placement speaker system and its sound after fine-tuning were so different that it was hard to believe they were the same system.

<< Concert Halls' Positive Influence on Sound System Equipment >>

Recently, I have noticed a change in the atmosphere of conversations among the people who staff the sound system booths at opera houses and concert halls. In the past, these technical personnel seemed to speak a different language than was heard in the rest of the hall or opera house. Now, they are beginning to talk about sound systems in a way that communicates better with the classical music world. This is a favorable trend. Instead of amplified sound that makes the audience want to cringe and cover their ears, halls and audiences want sound system equipment that produces sound to match and blend with the natural tones of acoustically played instruments. This new world of sound system design is born of the needs of concert halls and opera houses, an influence likely to spread well beyond those walls to the many venues where sound systems are installed.

Nagata Acoustics News 99-2iNo.134j
Issued : February 25, 1999

Nagata Acoustics Inc.

E-mail: info@nagata.co.jp

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