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

Nagata Acoustics News 99-11 (No.143)
Issued : November 25, 1999

Epochal Tsukuba-Japan's New International Conference Center

by Toshiko Fukuchi

Epochal Tsukuba Large Hall
On June 1, 1999, Japan Science and Technology Corporation and Ibaragi Prefecture unveiled Japan's newest international conference center, Epochal Tsukuba. The new conference center is located in Tsukuba "Science" City, the well-known home of the Japanese high-tech scientific and academic research community that was built from scratch in the 1980s.

The project architect, Sakakura Associates, was chosen through a design competition process. Building construction was contracted to a joint venture of Konoike Construction and others, the electrical work was performed by a joint venture of Kinden and others. A joint venture of Sanki and others was responsible for HVAC systems.

To reach Epochal Tsukuba from downtown Tokyo, one takes a direct express bus to Tsukuba Center Bus Terminal (about a 60-minute ride). From the terminal, the center is a 10-minute walk along a pleasant pedestrian deck. The site is southeast of the bus terminal. A park borders Epochal Tsukuba to the north, while a row of electronics and electrical appliance stores face the conference center on its south side.

<< 19 Rooms for Gatherings of 20 to 1,258 Persons >>

Epochal Tsukuba has one Large Hall, with a maximum seating capacity of 1,258 persons. Alternate rows of this room's ground-floor seating can be folded back into desks to provide a comfortable seminar setting for an audience of up to 808 people. There are three smaller halls: "Middle Hall 200" seats up to 200 persons; "Middle Hall 300" seats between 200 and 400 people depending on the arrangement of chairs and desks; and a multipurpose hall seats between 300 and 600 people. In keeping with the convention center's objectives, the facility also has 15 conference rooms with maximum occupancy loads that vary from 20 to 500 persons.

<< The New Building Surrounds an International Residential Structure >>

In the center of Epochal Tsukuba's site stands a residential structure that houses an international community of visiting researchers, professors and other guests. The new conference center was built around the living facility. Epochal Tsukuba's Large and Middle Hall 200 are located together in one wing, and the other rooms are located in a separate, 4-story wing. The two wings are connected to each other through an ingenious atrium-and-corridor layout.

All of Epochal Tsukuba's rooms, except for the Large Hall, face onto the atrium. The Large Hall overlooks the yellow exterior wall of Middle Hall 200 and the wing of other conference rooms.

Visitors to the conference center enter via the main entrance on the south side of the facility (the side facing the row of electronics stores). From the entrance, they pass immediately into the atrium, which provides quick access to all of the conference rooms. The layout makes it easy for even first time visitors to find a specific room. Both the northern exterior wall of the structure and the exterior wall of the main entrance are constructed of glass blocks and glass panels. This makes the park on the north side of the center visible inside the atrium and in the center's restaurant. The view of the park and natural lighting from outside gives these areas of the center an airy and welcoming ambience.

<< The Conference Center's Acoustical Requirements >>

The acoustical environment desired in conference centers focuses on three considerations. These are:

1. Sound Isolation.
Sounds from one conference room should not be audible in adjacent rooms.

2. Reverberation Control.
In order to ensure clarity of the spoken word, the reverberation characteristic of the rooms should be short enough that reverberations do not make speech difficult to comprehend.

3. Noise Attenuation.
Noise from HVAC equipment should not be so loud as to be disruptive.

Among the above considerations, sound isolation has the most critical impact on the facility's operations, because it affects the ability to use adjacent rooms simultaneously. If adjacent rooms cannot be used simultaneously, the center cannot make efficient use of its space and revenues immediately diminish significantly. Accordingly, for conference centers that have a large number of conference rooms, ensuring that all of the rooms can be used simultaneously takes highest priority and is an essential acoustical requirement.

<< Achieving Excellent Sound Isolation at Epochal Tsukuba >>

The first step in achieving excellent sound isolation for Epochal Tsukuba's conference rooms was to set the technically quantifiable goals we wished to achieve. Because the center's conference rooms include a great variance in scope and elaborateness, and because some the adjacent rooms would both be equipped with audio-visual equipment that can produce large sound volumes, we set our goal for each room's sound isolation characteristic at D-50. Architectural Institute of Japan suggests office conference rooms should have a sound isolation characteristic of D-50 in order to be rated as having excellent sound isolation. For each conference room's reverberation time, we aimed for an average absorption rate of 0.25, and we set our equipment noise attenuation goal at NC-25 to 30.

The "isolation" of Epochal Tsukuba's Large Hall and Middle Hall 200 in a separate wing made the conditions for achieving these rooms' sound isolation most favorable. The dense concentration of large, medium, and small conference rooms in the 4-story wing, however, required increased attention to prevent sound transference from impact noise produced on the floors of rooms overhead, as well as greater attention to sound isolation. Our strategy was to implement floating-floor construction for the second and third floors of this wing.

<< Superior Materials and Extra Care Produce Superior Results >>

The walls separating one conference room from another were constructed of dry board materials (as opposed to being made of poured substances). Since we had set our sound isolation goal at D-50, we selected wall materials that had catalog and lab ratings of D-55, one rank above our desired goal.

We also launched an educational campaign with all of the contracting companies on the job site to alert them to the impact their work would have on the ultimate sound isolation measurements. Usually, when contractors think about sound isolation work, they assume that only the builders' work is involved. However, gaps are often created where HVAC ducts and electrical conduits penetrate sound isolation walls, reducing the performance of the sound isolation materials. Therefore, every company engaged in the project's construction work needs to be aware that the precision of their workmanship will affect the sound isolation performance of the completed structure.

By discussing our sound isolation objectives with each of the contractors, and explaining to each of them what precautions and care they should use, we were able to get all of the work groups to be conscious of their roles in achieving the sound isolation goals. In addition, we inspected the job site frequently (once or twice each month) to check that our requested procedures and standards were being implemented. The successful result was that the conference center's sound isolation performance exceeds our goals, achieving measurements of D-55 to D-65. Of course, I would like to thank the well-run project management of the architectural design office, as well as the cooperation of all of the contractors, for their contribution to this success.

<< The Difficult Dilemma of Choosing Conference Room Doors >>

Another factor that critically affects sound isolation performance is the choice of sound-isolating doors. The problem that we always face is that the physical properties that enable doors to open and close easily are diametrically opposed to the properties that ensure effective sound isolation. If we prioritize the doors' opening-and-closing function, we end up with large gaps that make sound isolation problematic. Conversely, if we place too much emphasis on the doors' ability to isolate sound, we end up with doors that are difficult to use. In order to realize both priorities, substantial consideration must be given to both the design of the door and frame assembly, and to how the doors are adjusted after they are hung.

For the conference rooms of Epochal Tsukuba, single-layer, non-overlapping theater doors had been preselected because of their ease of use. In addition, all of the conference room doors open onto the atrium, where there is likely to always be a certain level of sound unrelated to the proceedings in each room. In order to achieve effective sound isolation at the door areas, we used elastic materials to make each door airtight on all sides. Additionally, we augmented our prevention tactics by specifying the use of an absorptive combination perforation board and glass wool material. The latter is aimed at attenuating the higher range sounds created by air passing through door gaps.

<< Shaping the Center's Halls for Better Acoustics >>

The configuration of the center's Large Hall, in plane perspective, is fan shaped. The Middle Hall 200 is egg-shaped. Both of these shapes often suffer from pockets where sound tends to concentrate. In the Large Hall, we forestalled this problem by designing the rear wall in the shape of an arc. For the Middle Hall 200, we designed absorptive ribbing to extend along the curved side walls and across the back wall as well. The result is that neither hall experiences any echo, even from the clapping of hands. This is the best acoustical environment for conferences.

The conference center's sponsors additionally requested that the Large Hall be moderately adaptable for piano and other musical performances. To accommodate this request, we installed stage reflection panels.

<< A Nobel Laureate at the Helm >>

Epochal Tsukuba's first executive director has already arrived on the scene. He is physics Nobel laureate Dr. Leo Esaki. At the center's inaugural ceremonies, I heard that the conference center would be nearly fully booked through the end of this century. Given Tsukuba City's international connections and the continued prominence of Japan on the world stage, I am sure that most of Epochal Tsukuba's events will have a global flavor. But I was glad to also hear that plans are in progress to develop programs for the local city and prefectural population as well. Tsukuba City is now ready to host the world-class conferences of humanity's 21st century epochs.

For more information, please contact Tsukuba International Congress Center at 81-298-61-0001.
The address is 2-20-3, Takezono, Tsukuba City, Ibaragi Prefecture, Japan 305-0032.
Information about Tsukuba Science City can be found at www.k2.tsukuba.ac.jp

Big Success in a Small Town: Many Lessons Can Be Learned from Kuse-cho's Espace Hall

by Yasuhisa Toyota

Kuse-cho is a small Japanese town, well off the beaten path. The easiest access is from Okayama Prefecture's Okayama City (which itself is an hour by train from Osaka). Travel north on the Tsuyama and Kishin train lines for nearly two hours, including changing trains once, and at last you will arrive at Kuse-cho.

Two years ago, in 1997, this modest town, with a population of 12,000 people, opened the doors of a new 500-seat multipurpose hall designed primarily for concert performances. (To read about the opening, go to our May, 1997 News & Opinions.) Since its opening, the hall has maintained an incredibly healthy utilization rate of more than 85%. In Okayama Prefecture, this utilization rate is surpassed only by Okayama Symphony Hall in Okayama City, a major metropolis. When the limited scale of the town's resources are taken into consideration, Espace Hall's ability to keep its utilization rate so high is truly astounding.

Because I was curious to learn more about this hall's unequivocal success, I paid a visit to Mr. Tokumasa Ujihira, the Executive Director of the Kuse Espace Promotion Foundation. The Foundation was established through a grant from the town's public coffers. The Foundation is run by a staff of six persons, including Mr. Ujihira. Four of the six foundation employees are civil service employees, with their salaries paid by the Kuse-cho local government.

<< Financial Overview of the Hall's Operations >>

Espace Hall's annual operating budget is approximately \170 million ($1.6 million). The annual budget includes all normal operating expenses for the hall, plus the budget for a library housed on the hall's premises, facilities costs for the operation of the town's local cable television channel, and the maintenance and administration of an old schoolhouse building that is an historical landmark. The hall earmarks approximately \40 million ($380,000) per year for the development, promotion, and production of in-house concert programming.

<< The Executive Director's Vision >>

Mr. Tokumasa Ujihira
Executive Director
Executive Director Ujihira is very clear about his objectives for Espace Hall. He says, "No matter what plans or ideas may pop up, what is most important to me is that the people of this town make active use of this hall. And I have a dream for the hall to become a source of artistic inspiration. Like a beacon, Kuse-cho will send out some data, and the artists out in the world will respond. I set no limits on the efforts I am willing to invest in Espace Hall, and I am ready to adapt and change and do whatever is necessary for this goal."

Mr. Ujihira's connection with Espace Hall began when he was assigned oversight responsibilities during the hall's planning and design stages. His unbridled enthusiasm for the project led to his present assignment as the hall's Executive Director.

<< A Multipurpose Hall Design with a Focus on Classical Music >>

Espace Hall's architectural and acoustical design fit in the category of multipurpose hall. Specifically, because the local cable television channel also uses the hall, we label this kind of hall a "multifunctional hall." Nevertheless, during the design of the hall, the town clearly expressed its desire to prioritize achieving acoustical characteristics that are especially appropriate for the performance of classical music.

As the acoustical consultant to the project, Nagata Acoustics devised a number of strategies to satisfy the town's desire to favor classical music performance within the overall multipurpose (or multifunctional) hall environment. The most notable aspect of our design is Espace Hall's high ceiling above its proscenium stage. Implementing this design element maximized the overall volume of the hall's interior space.

Kuse-cho came to Nagata Acoustics with a clear idea of the kind of hall it wanted. In working with the town to achieve its objectives, Nagata Acoustics found it valuable to establish some clear ground-rules with the client. We asked that there be no vacillation about the classical music focus during the design and construction phases of the hall. Throughout the project, we urged and reminded the town's representatives not to interrupt or detour the design process by being uncompromising. Some of the multipurpose aspects of the hall might need to be given secondary status in order to achieve fine concert hall acoustics. But we also urged Kuse-cho about something else. We told the town that once the hall's construction was completed, and the hall opened for use, then it would be time to actively promote and encourage diverse use of the hall and performances of multifarious genres, while keeping in mind Espace Hall's special acoustical characteristics.

<< The Hall's In-house Programming Activities >>

In the two years since Espace Hall opened, a medley of genres have been performed in the hall. Among the many calendared events have been classical music concerts, jazz performances, pop music extravaganzas, and even film showings. Despite the limited nature of the hall's annual programming budget, the line-up of major names who perform at Espace Hall rivals the offerings of venues in much more populous and easily accessible Japanese cities.

Most of the visiting artists are Japanese performers and ensembles, such as the Japanese drum ensemble Kodo, chamber music ensembles from the Tokyo-based NHK Symphony Orchestra and New Japan Philharmonic, internationally famous Japanese jazz musicians Terumasa Hino and Sadao Watanabe, and the Junko Ohnishi jazz trio. But the hall has also sponsored performers from abroad, notably the Vienna Piano Trio. From the popular music world, Saburo Kitajima, Kentaro Hayami (Dango 3 Kyodai) and Kentaro Haneda have all starred in Espace Hall programs, and theater lovers may recognize the name of Tokyo's Gekidan Shiki, which has staged theatrical works at Espace Hall.

Of course, success breads success, and the hall's ongoing ability to sponsor in-house programming cannot be separated from its past successes in filling the hall's seats. The hall's in-house programming consistently draws sell-out or near-sell-out audiences. This kind of success rate does not happen without considerable effort and planning.

<< Espace Hall's Recipe for Successful In-house Programming >>

The Espace Promotion Foundation's six employees follow an established process for creating and producing successful in-house programming. First, they thoroughly debate and discuss what concerts or events they will sponsor. Each of the six staff members are allowed to let their own interests and preferences influence their decisions as program producers, but one inviolable requirement must never be forgotten throughout the entire discussion, planning, and negotiating process. This one precondition for each and every program is that it must have the potential to become a sell-out box-office success.

Once the Foundation decides to sponsor a program, one of the six employees takes on the responsibility for managing the project. When a program matches the individual interests of an employee, managing the project becomes especially rewarding. This is probably the only "perk" the Foundation's employees enjoy, since the bulk of their work-time is spent attending to the many details of hall management and operation.

In addition to the edifying work of producing in-house programming, the six employees together carry out all of the tasks needed at the hall, including running the box-office and foyer area, and performing all of the back-stage preparations and other labor. Espace Hall policy is to offer round-the-clock operations, so if a request is made, the hall can be open and available from any hour of the early morning to any time late at night. While the six employees do find some support in a contingent of hall volunteers, it is not unheard of for the six employees' workday to last into the middle of the night. From most people's perspective, this would definitely be considered a hard, labor-intensive job. But the individuals employed at the Foundation say they love their work and there is nothing else that they would rather do.

With in-house programming reaching 40 programs per year, the workload of the Foundation's staff averages out to one major performance almost every week of the year. Yet, the employees say that when they have a week in which there is no hall-sponsored program, they feel as if something is missing. Even the four civil service employees on loan from the Kuse-cho government are trying to find some way to prevent being rotated out of their current positions, though they readily admit that the pace of work at the hall is intensely busy.

<< A Non-bureaucratic Approach Breeds a Dedicated Staff >>

Why do the six Foundation employees who run Espace Hall share such strong dedication for their work? My guess is that they are hooked on the liberated, individual-affirming system and atmosphere at Espace Hall. The way programming is developed, and the way the six employees interact is as different from traditional office bureaucracy and hierarchy as can be.

In Japan, most halls have a board of directors that micromanages operations. Any change that the on-site staff desire is referred to the board for its opinion and approval. But Espace Hall's Executive Director Ujihira explained to me that Espace Hall's board meets just three times each year. More importantly, at the board meetings, the agenda basically includes only three topics: the budget; the Foundation's balance sheets; and approval of the staff's general planning objectives for operating the hall.

It is significant that all of the decisions regarding planning and programming details, as well as execution of the hall's daily operations, are left entirely to the discretion of the six employees. The "hands-off meddling in daily operations" policy of Espace Hall's Board of Directors is also very different from traditional foundation bureaucracy and hierarchy management methods.

Mr. Ujihira and the other hall employees respond to the board's delegation of authority with a heightened sense of responsibility. They know that if their ideas and work prove unsuccessful, they will have only themselves to blame. In Japan, of course, taking the responsibility for failure means resigning one's post, and on this count, Espace Hall's six "samurai" would not expect the board to be lenient. The stakes are especially high because all six of the hall staff truly love their work.

<< Serving an Audience Willing to Pay for Quality Programming >>

Mr. Ujihira says that when the hall opened, nearly three years ago, his staff's programming work succeeded mostly through simple trial and error. Now, however, they are gaining increased understanding of what kind of programming will be successful. "Something I found interesting to learn," he told me, "is that lower ticket prices do not necessarily ensure more ticket sales. Unless the content of a concert really appeals to the audience, the event will not be a success. If the programming is something especially worthwhile, the tickets will sell even if we must price them a little higher than what we would like to charge."

Mr. Ujihira also says that if he can expand the hall's budget by about 25% (approximately $94,000), he is certain that the excellence and creativity of the hall's programming would soar. I could hear his passion when he explained, "All the programming we have done up to now has been like purchasing something off a rack, ready-made. I want to see some of Kuse-cho's ideas incorporated into programming that will be "custom-tailored" to fit our hall and our audience."

<< Strong Enthusiasm for Local Talent >>

I was told that many of the hall's attendees come from neighboring towns as well as from Kuse-cho. The local population definitely knows the best way to support its local musical talent-it turns out in large numbers for performances by local artists! On the date that I visited Espace Hall, a local Piano Duo was scheduled for an evening concert. Not only did the tickets for this concert sell out, but there were also standing-room-only listeners at the rear and sides of the hall.

Another indication of Espace Hall's symbiotic relationship with local musicians was a large banner I saw hanging prominently in the hall. The banner congratulates Kuse-cho Middle School's Wind Ensemble for winning the chance to participate in a Japan-wide competition. This is the first year that Kuse-cho Middle School will be represented in a national event. Espace Hall helped foster and encourage this youth ensemble. Its recent success is at least a small step toward Mr. Ujihira's dream for Espace Hall to be a cultural beacon outward from Kuse-cho as well as a receptacle bringing outside performers to the town for the local population to enjoy.

<< Halls Should Study the Operational Successes of Other Halls >>

When halls are in the planning and design stage, there always seems to be plenty of funding for study and observation tours of halls both in Japan and around the world. Everyone-from the individuals directly involved in the design and construction project to elected officials-travel far and wide to look at hall configurations and other physical aspects of halls. However, I rarely hear of a trip being funded, after a hall opens, so that the operations staff can study and observe how successful halls make success happen. I think that investing in this kind of study and observation would benefit many halls. I would certainly put Espace Hall high on the list of "must visits" for anybody planning a hall operations study tour.

Espace Hall can be reached by telephone at 81-867-42-7000, and by fax at 81-867-42-7202.

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Nagata Acoustics News 99-11iNo.143j
Issued : November 25, 1999

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