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




Nagata Acoustics News 98-2iNo.122j
Issued : February 25, 1998





"Sakura-mate" Cultural Creativity Pavilion Opens in Kumagaya

by Satoru Ikeda

Sun Hall (1000-seat large hall)
"Sakura-mate" Cultural Creativity Pavilion (Outside View)
Kumagaya City's second municipal performing arts center, named "Sakura-mate," opened for the first time on January 10, 1998. Its January, February, and March calendars are commendably booked with an array of performances, beginning with the inaugural performance on opening night by the Saitama Symphony Orchestra. This was followed the very next day by a concert featuring the NHK Symphony Orchestra and, thereafter, weekend performances that included the Matsuyama Ballet Company, the dedication of the hall's piano in a recital by Japan'sdoyenne of pianists, Hiroko Nakamura, concerts by the Berlin Philharmonic's Scharoun Ensemble, Chorus Circus, and others. February's calendar features performances by local groups, and March will bring an original musical, "The Yellow Bat," to Sakura-mate's stage.

To reach the new cultural creativity pavilion, one travels on the JR Takasaki Line (in Saitama Prefecture) one stop past Kumagaya to Kagohara Station. The pavilion is located about one kilometer from the south exit of Kagohara Station. The new Kumagaya Cultural Creativity Pavilion was planned to complement Kumagaya's two other municipal buildings where cultural activities are held: Kumagaya First Culture Center and Kumagaya Kaikan. Together, the three structures are intended to serve as a hub where residents of the city and surrounding areas can gather to participate in creative cultural endeavors and activities.

Yoshiro Ikehara Architect & Associates developed the architectural design and oversaw project management for the Cultural Creativity Pavilion. A.T. Network provided theater consulting expertise, and Nagata Acoustics served as the acoustical design consultant.

Initially, the Kumagaya project called for a comprehensive and ambitious two-stage development plan, including a Second Culture Center comprised of five wings, one housing a large and a small hall, rehearsal rooms, and related facilities, and conference wing, museum wing, library and educational seminar space wing, and restaurant wing. In the original design, visitors would arrive to a raised parking garage on an artificially constructed hillock. A bridge approach would take the visitor to a glass, half-open courtyard area from which each of the two pavilions could be separately accessed. The brick and glass exterior design was to make a striking appearance, enhanced by the semi-circular grass of the courtyard garden and greenery planted on the roof of the garage "hillock." On clear-weather days, the beautiful landscape of mountain peaks such as Mt. Nantai, Mt. Akagi, Mt. Myogi, and the Chichibu Mountain range, would bevisible in the distance beyond the garage hillock, and be seen even better through window-panelled elevators that would take visitors to an observation point on the roof of the large hall.

The new Sakura-mate Cultural Creativity Pavilion represents the completion of just the first stage of the project that was originally planned. It contains a theater wing, conference wing, and restaurant wing, all of which are positioned so that only the theater's north side (facing toward the courtyard) is exposed to the "colder view" of the northern landscape.

The theater wing of the pavilion houses a 1000-seat large hall, named the Sun Hall, a 250-seat-capacity small hall, named the Moon Hall, and five rehearsal and practice rooms, including one that is directly appended to the two concert halls. As can be easily discerned from the preponderance of rehearsal and practice rooms, the fundamental planning of the pavilion emphasizes the day-to-day use of the facilities by the local community. The large hall is designed topromote its use by a wide spectrum of cultural groups. Rather than being designed for just one genre of performing arts, it is multi-functional, but with specifications geared toward a set of clearly defined uses that the hall's planners know are artistic forms pursued by local people.

<< The Sun Hall >>

Because the pavilion will serve as the home base for Saitama Prefecture's oldest orchestra, the Saitama Symphony Orchestra, the large hall is designed as a proscenium-type, multi-functional hall with the acoustical design emphasis placed on the performance of classical music. We chose a shoebox configuration as the best match for both the intended musical use of the hall and its 1,000-seat scale. The multi-functional proscenium stage increases the hall'sversatility and enhances the impression of intimacy between audience and performers, as well as having a positive affect on the hall's acoustics. We further upgraded the stage with reflection panels that run along the rear of the hall.

A unique design feature of the Sun Hall comes from the ability to open the rear of the stage to the out-of-doors. When the rear of the stage is opened, it forms a half-oval open-air theater, named the Wind Theater. Only a locale such as Kumagaya, known in Japan as the city with more days of blue skies than any other, could be home to such an adventurous architectural and acoustical design.

Inside the Sun Hall, the ceiling is designed to inspire thoughts of the open skies, while the side walls stand sharply at either side, creating a most memorable and subtly peaceful atmosphere.

<< The Moon Hall >>

We designed the smaller Moon Hall with the expectation that it will be used on an almost daily basis by many different local cultural groups, clubs, and societies. To achieve the greatest range of variations in both stage and seating configurations, the initial design of the Moon Hall called for a floor with electrically-powered sections that can be raised and lowered in a myriad of ways to create a stage and terraced seating. In the end, however, this design was simplified to create a multi-event space in which only the stage portion of the hall can be raised and lowered, while the remainder of the hall has non-variableflat flooring.

The wall behind the stage area of the Moon Hall is entirely made of glass. Therefore, performances in this hall can benefit from an expansive outdoor feeling in their productions. As the hall is excellently suited for large exhibitions and receptions, we separated it from the foyer by double-layered movable partition walls, so that these can be removed as desired to create one, larger space. Compact in overall size, the Moon Hall lends itself well to a limitless variety of events, performances, and other uses.

<< The Acoustical Challenges of Sound Isolation >>

From the acoustical engineering perspective, Sakura-mate Pavilion's biggest challenges were primarily issues of sound isolation and insulation from external noise. The foyer is located next to both the large and small halls, so the sound of these spaces needed to be sufficiently isolated from seeping into the neighboring spaces. In both the large and small halls, we used the expansion joint structure and, because we had the full and cooperative understanding of the entire architectural team, we were able to achieve results that confirm the positive effects of the expansion joint structure. Because of their unique designs, the rear walls of both the large and small hall are particularly vulnerable to having outside noise leak into the halls, so this possibility needed to be prevented. Isolating noise from the elevators in the elevator tower and from the rooftop observation deck, as well as designing a reduced-noise ventilation system that directs air out from underneath the hall's seating were all sound isolation issues that required our serious attention.

<< Room Acoustics >>

With regard to the room acoustics in the pavilion's two halls, acoustical engineering issues arose from the complex and uneven surface that the architects chose for the ceiling and from the use of a shoebox configuration for the large hall. For both acoustical and aesthetic reasons, on-stage reflection panels were added to the large hall for both its inside and open-air stages, and sound-diffusing shapes were added to the side walls.

In designing the electrical acoustical equipment, we did not encounter the often prevalent difficulties of finding space to house the electrical acoustical system and the layout of main speakers. Rather, we easily determined to place the proscenium speaker in full isibility of the audience, while the side speakers are situated out of sight, embedded in the side walls.

Kumagaya is a city famous for its beautiful cherry blossoms. Now a new "cultural tree" has been planted that will surely yield its own beautiful blossoms in the form of the performing arts. In keeping with the hopes of the pavilion's planners, the new structure will be a stimulus for the dramatization of great literary and cultural works. It will be the "franchised" home base of the Saitama Symphony Orchestra. The pavilion's administration has taken the rare action of opening up the planning process to the general public and is following an uncharted course in its approach to programming and management.

A month before the official opening, the public was invited to come view the new pavilion, and the inaugural concert was packed full. Best of all, the hall is truly being used by the local people, who are displaying their venerable talents more and more. I hope that Sakura-mate Pavilion continues its much needed work of being not just a local cultural center, but truly a cultural center of the people who live and work in its vicinity. (For more information on the Kumagaya Cultural Creativity Pavilion, please contact its administrative offices directly at 011-81-485-32-0002. The pavilion' address is 111-1 Zyurokuken, Kumagaya City.)




A Visit to British Columbia University's Chan Center for the Performing Arts

by Keiji Oguchi

Chan Center for the Performing Arts
In this month's and next month's newsletter, I will share my observations of two halls I visited during my tour of Canadian and European halls in November and December 1997. This month, I will discuss the Chan Center for the Performing Arts, which was completed last year at British Columbia University, in Vancouver.

The Center is an oval-shaped building and houses a concert hall, playhouse, and a cinema. Chan Shun Concert Hall seats 1,400 persons. It is named in honor of the Chan Family, who contributed substantial sums of money toward the Concert Hall project and were the largest contributor to the campaign that enabled the concert hall to be built. The acoustical consultant for the concert hall was Artec Consultants in New York, under the direction of Russell Johnson. Chan Shun Concert Hall repeats the shape that Mr. Johnson has been using in recent years, notably for his symphony hall in Dallas and Birmingham. Chan Shun Concert Hall is basically a shoe-box configuration, except that both ends of the main floor are rounded. Two tiers of balconies circle the main floor. A unique design feature of the hall is its high ceiling. Of course, a large, movable canopy is suspended above the stage. Incredibly, this canopy weighs 37t, and houses both the stage lightings and loudspeakers! An aspect of the Chan Shun Concert Hall's acoustic design that distinguishes it from the Dallas and Birmingham halls is the lack of a reverberation chamber around upper walls and ceiling. Because the wall around the back of the stage is acoustically transparent punched metal, it appears that Mr. Johnson's intent is to have the area behind this wall serve as the reverberation chamber. The Chan Shun Concert Hall interior is rough-finished concrete with maple-wood accents. Retractable, acoustically absorbent bannerss have also been installed along all the walls to enable adjustment of the hall's acoustics.

I visited the hall during a rehearsal of the university's brass band. The canopy was suspended at a height of approximately 9 meters and the banners were completely unfurled along the walls. My impression while listening to the rehearsal from the balcony seating was a true brass sound and the length of the reverberation seemed exactly right. Consequently, my supposition is that the sound would be somewhat dead with a full audience. When I moved to a location behind the stage, I discovered that the punched metal wall is half-blocked by paneling. Nevertheless, the rehearsal performance sound was very real. The height of the canopy and deployment of the banners is decided among the musicians, conductor, and the hall's staff, based on advice provided by Mr. Johnson. The hall staff that guided me through the hall shared with me that the university's music department personnel and local Vancouver musicians initially were uncertain about the hall's long reverberation time. However, when I Musici from Italy performed at Chan Shun Concert Hall, they commented on what a wonderful hall it is, and this allayed everyone's concerns about the hall. I found it heartwarming to hear this story, as it so often happens in Japan as well that it takes the approval of a musical group visiting from ab road to put the stamp of approval on a hall's acoustics.

Both the Center's playhouse and cinema are also each named for a donor to the project. The playhouse is named the BC Tel Studio Theatre, and the cinema is the Royal Bank Cinema. In the playhouse, the towered seating can be moved using a pneumatic system, enabling variations to the proscenium, thrust stage, center stage, and the seating directly in front of the stage. The theater consultant for this project was Theatre Projects Consultants of London, England.




A Personal Use Audio Product that Really Gets Rid of "Da Noise"

by Yasuhisa Toyota

Wherever one goes these days, regardless of whether the people one sees are old or young, at work or at play, everyone seems to have a "Walkman-type" piece of audio equipment and their ears covered with tiny headphones. I am not personally fond enough of this kind of audio equipment to use it day in and day out during my train commute. But for a while I thought it the perfect companion to help me whittle away the long hours I must often spend on international air flights, and I had purchased a portable CD player for this purpose. Unfortunately, as many airplane travelers have undoubtedly discovered, the noise level in an airplane is so loud that it is futile to try to enjoy many works of music, especially classical works with piano and pianissimo in their scores.

After letting my portable CD player and head set go unused for a while, I unexpectedly discovered a useful upgrade for this kind of listening -- a headset that contains a noise cancellation function. According to the product information that accompanied the headset, it produces a sound that is the inverted phase of the noise from outside the headset, so that the two sounds cancel each other out, thereby decreasing the effects of the outside noise. The headset has a very tiny amplifier which performs the noise cancellation function, and is powered by one AAA 1.5 volt battery.

While the concept of using inverted sound phases to cancel out noise is not a particularly new concept, its use in product applications is a noteworthy new technological development. I was surprised to find the concept applied to a product that has become such a ubiquitous part of everyday life. Nevertheless, when I purchased one of these headsets at a Japanese mass merchandise camera outlet (for about 10,000 yen), I was skeptical about whether it would really produce the desired effect or whether I had been hoodwinked.

I immediately tried out my new headset on an next international flight. I was truly amazed at the dramatic difference I heard using the noise cancellation function! The sound level of the airplane noise that I heard with the headset on was probably on the order of a 20dB reduction. I had no trouble hearing the piano and pianissimo portions of the recording I was enjoying. This headset -- actually, set of ear pods -- nestled easily and comfortably in my ears. By inserting the pods in my ears, I seemed to decrease the airplane noise by approximately 10dB, and when I turned on their switch, I experienced a further reduction of approximately 10dB. Of course, this powerful and valuable addition to my portable CD-player equipment of course works equally well with any portable tape player or the increasingly popular MD players.

Even without plugging into a CD player or tape player, the noise cancellation headset serves a practical purpose as very effective earplugs. Anyone who cannot sleep in an airplane due to the constant engine drone should certainly give one of these pairs of ear pods a try. In addition, since most international flights now use headsets with regular-sized plugs for in-flight movie and music listening, a traveler can use the noise cancellation ear pods to enjoy the recorded flight music and movies free of distracting noise.

Satisfied with the results of my first little experiment, I proceeded to try out the noise cancellation headset on a commuter train. In principle, the positive effect of the technology should decrease the higher the frequency of the sound. Certainly, I did not obtain the same dramatic improvement in listening quality that I had experienced on my international air flight. Still, there was enough of a change that the improvement was clearly noticeable. The pamphlet accompanying the headset claims that one AAA battery lasts approximately 30 hours, an eminently practical duration. The headset I purchased was manufactured by Sony (MDR-NC10 : Noise Canceling Headphone); other audio manufacturers may already have similar models on the market. For audiophiles and persons with acute sensitivity to noise, this is a product that may substantially improve your on-the-go listening pleasure.


Nagata Acoustics News 98-2iNo.122j
Issued : February 25, 1998


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