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

Nagata Acoustics News 00-04 (No.148)
Issued : April 25, 2000

Paruru Hall Opens in Chiba

by Yasuhisa Toyota

Audience area of Paruru Hall
Stage of Paruru Hall
Chiba Prefecture, located to the east of the Tokyo Metropolitan Area, tends to receive little International attention. Yet, the prefecture is the true gateway to Japan, being the home of Narita International Airport. The prefecture also has many bedroom communities and thriving commercial neighborhoods, especially near major train stations. One of these stations is the JR Chiba Station.

Now, a new, 720-seat concert hall, "Paruru Hall" has opened just a few minutes' walk from JR Chiba Station. The hall occupies part of a multipurpose structure funded by the Japanese Ministry of Posts and Telecommunications. This governmental body has paid for many halls and public-use buildings throughout Japan, using funds earned from the Ministry's bank-like operations. (In addition to postal services, the Ministry offers savings account and other popular, low-risk investment vehicles and banking services.) The Ministry's stated goal in funding facilities such as Paruru Hall is to support and stimulate regional cultural activity throughout Japan.

<< A 10-story Multipurpose Building Designed by the Client >>

The new, multipurpose building that houses Paruru Hall is a 10-story structure. Paruru Hall is the main focus of the building, which also has an athletic gym and swimming pool, meeting rooms, a restaurant, a post office, and other facilities.

This project's client, the Postal Ministry, developed the building's architectural design in house. Specifically, the Postal Ministry's Secretariat Facilities Department and Kozo Keikaku Engineering Inc. shared responsibility for the building's design. A consortium of companies, including general contractor Okamura-gumi, participated in joint-venture construction management of the project. Nagata Acoustics performed the acoustical design and consulting.

<< Paruru Hall's Specifications >>

Paruru Hall was planned and designed as a conventional shoebox-configuration concert hall with one balcony. The hall's plan-view dimensions are 16m (52.5 ft) x 34m (111.5 ft). The ceiling height (measured from stage floor) is 13m (42.7 ft). The stage depth is 8.5m (27.9 ft).

The hall's interior is finished mostly with wood materials and the overall atmosphere is refined and without ostentation. The setting is appropriate to the intended use of the hall, which is primarily the performance of classical music. Paruru Hall's reverberation time (with full occupancy, at 500 Hz) measures 1.6 seconds.

<< A Chameleon Stage Increases Options for Paruru Hall's Uses >>

Following our client's wishes, Nagata Acoustics' designed Paruru Hall with a strong focus on its use as a classical music concert hall. Nevertheless, while maintaining the authenticity of the shoebox configuration hall, around the stage area we incorporated capabilities for acoustical adjustments and variations in order to broaden the range of performance genres that the hall can accommodate. Specifically, the portion of the ceiling above the stage can be retracted to allow the use of stage and lighting equipment. The acoustical characteristics of the hall can also be customized through the retractable ceiling.

In addition to the ceiling, several options were incorporated into the design of the rear wall of the stage. A system of door panels enables deployment of either a reflective or sound-absorbing surface, and a retractable curtain along a portion of the rear of the stage further increases the possibility of adjusting the hall's acoustics to suit the needs of performers. All of these supplemental stage functionalities will be useful in customizing the hall for each performance to enhance the hall's acoustics for the different kinds of performances that may be included in the general classification "classical music."

<< Structural Features of the Acoustical Design >>

Structurally, the most notable feature of Paruru Hall's acoustical design is the use of anti-vibration pads throughout the foundation structure to create a floating foundation. Paruru Hall has the advantage of easy mass transit access via the JR railroad system, but this advantage is a double-edged sword. The hall's building is in extreme proximity to the rail tracks. At its closest point, the distance from the tracks measures barely 20m (66 ft). Accordingly, anti-vibration and anti-noise planning were an integral and critical aspect of our acoustical design from the inception of this project. We added 50mm (2")-thick anti-vibration pad material along the subterranean portion of the building's walls and used generous deployment of anti-vibration pads around the hall's framework to give the hall a floating foundation. As a result, we achieved a level of sound and vibration isolation that ensures noise and vibrations from passing trains are completely unnoticeable in Paruru Hall.

<< Post-construction Testing and Fine Tuning >>

Paruru Hall's construction phase was completed five months prior to the hall's official opening. During the following final period before the hall's opening to the public, Nagata Acoustics conducted acoustical testing, checks and fine tuning of the hall. We staged a test concert performed by a chamber orchestra and attended by an audience of people involved in the construction project. The New Philharmonic Orchestra Chiba performed Mozart's Symphony No. 40 and other works under the baton of Maestro Heiichiro Oyama, Kyushu Symphony Orchestra's chief conductor.

During the rehearsals for the test concert, we conducted numerous experiments to test the influence of the stage's adjustable settings on the sound heard in the hall. We were able to empirically confirm our expectations concerning the relationship (or lack of relationship) between quantitative measurements such as reverberation time and the differences heard by the human ear depending on how the stage was adjusted. Because the location of the adjustable aspects of this hall are in close proximity to the music source, quantitative measurements such as reverberation time do not change significantly when the stage settings are adjusted. However, the influence of the various settings on the way the music sounds to the human ear was easily distinguishable.

In order to achieve the optimal sound from Paruru Hall, those who perform in it will need to use their own ears and judgment to determine how to best adjust the stage's settings. The best setting will vary depending both on the configuration of the ensemble and the works included in specific concert programs. The acoustical possibilities offered by this hall are substantially expanded by the opportunity to adjust the rear and ceiling portions of the stage. Yet, a certain amount of trial and error will be required until the performing groups who use the hall consistently achieve the best sound possible on every occasion.

The test concert was a stellar performance. The chamber orchestra included some 20 musicians and their ensemble filled the hall with beautiful, rich sound. Everyone in the audience had some connection with the project and its construction, so our ears may have been prejudiced, but the reactions of delight at how this small ensemble resonated throughout the hall were spontaneous and candid.

<< Inaugural Concert and Paruru Hall's Future >>

On February 18, 2000, Chiba City sponsored Paruru Hall's official inaugural concert. The Tokyo Philharmonic Orchestra performed a program of "Masterpieces of Classical Music." But since then, there has been no stampede to fill the hall's calendar. A hall of this caliber deserves more frequent use.

I hear that Paruru Hall's approach to filling its calendar is fundamentally to rely on renting out the hall. In an article I wrote for this web page last September (News & Opinions No. 141), I strongly expressed my opinion that rental facilities should be designed with multipurpose-hall, and that the decision to fund a specialty hall, such as a classical concert hall, should be accompanied by a commitment to fund or support hall-sponsored concerts and programming. Like any specialty or niche commodity, when a hall is designed for a specific, limited range of performance genres, it is a great boon for these genres. But specialty marketing tactics and strategies are essential to ensuring frequent use of a specialty hall, just as they are critical to any niche product's success.

It will please me greatly if Paruru Hall's sponsors and administration take on the challenge of filling at least some of the open spaces in the hall's calendar. The public relations materials that explained the hall's funding claimed that the purpose of the hall is to support and sustain regional cultural activity. I would like to see Paruru Hall become a mecca for classical music activity in Chiba Prefecture. The maximum benefit from the investment made in funding the building of this hall will only be realized if investments are made in programming and concerts as well.

Once a hall is designed and constructed, its fundamental characteristics are pretty much "set in stone". However, one wonderful feature of hall planning and programming is its flexibility: programs, concerts and events can be devised and tried, reworked or scrapped and other programming put in its place. Like a new computer hard-drive with gigabytes of power, Paruru Hall is a wonderful opportunity waiting for the right "software" programs to make it hum. I hope that more than one person and organization will try downloading their vision into this excellent piece of hardware soon.

Commemorating the 88th Birthday of Prof. Yasuo Makita -
A Leader of Acoustical Engineering in Japan

by Dr. Minoru Nagata

Prof. and Mrs. Makita
This year, Prof. Yasuo Makita reached the truly venerable age of 88. (In Asian cultures, the age of 88 has been considered especially auspicious because it repeats the number '8,' the most lucky single digit number.) On March 18, 2000, we celebrated Prof. Makita's birthday at a gathering in Nakano Sun Plaza Hall.

The afternoon party was attended primarily by people like myself who once worked at the Acoustical Department of the NHK Technical Research Laboratories and who had the good fortune to be mentored by Prof. Makita and benefit from his presence there. A total of 31 NHK employees and former employees, plus 13 other academic and industry friends of Pr. Makita joined the celebration at Nakano Sun Plaza Hall, which faces the Nakano JR train station in a residential and commercial section of Tokyo, to spend a few hours enjoying the company of Prof. and Mrs. Makita.

Prof. Makita joined NHK Technical Research Laboratories in February 1951, from Osaka University's Acoustical Science Research Department. In June of the same year, the Acoustical Department was founded within the Laboratories. Prof. Makita was installed as the chief of the Architectural Acoustics Research Group in this new Department.

<< The 1955 NHK Hall and Prof. Makita's Book, Architectural Acoustics >>

The first project tackled by the Architectural Acoustics Research Group was a 630-seat hall included in a new NHK Broadcasting building then being constructed in the Shinbashi-Uchisaiwaicho section of Tokyo. From this hall, which opened in 1955 and was the first post-war concert hall to be named NHK Hall, musicians from Japan and abroad performed classical music concerts that were broadcast by radio into the homes of listeners throughout Japan.

Since I was one of the people responsible for the acoustical design of the 1955 NHK Hall, I will never forget the sound of that famous hall, even though it is now many years since it closed its doors forever. In 1974, a new NHK Hall opened in Shibuya, replacing the Shinbashi-Uchisaiwaicho NHK Hall.

From our experiences in designing the first NHK Hall, Prof. Makita wrote Architectural Acoustics (published, in Japanese, by NHK Hoso Shuppan Kyokai, in 1960). This was the first Japanese-language book devoted to the subject of hall acoustics. For myself and my colleagues at the NHK lab, it was the only textbook we ever had.

<< Our Work to Acoustical Design of Tokyo Bunka Kaikan >>

After designing the 1955 NHK Hall, we were given the challenge of a major project on a much grander scale than our earlier effort. Prof. Makita played a key role in the conceptual planning of Tokyo Bunka Kaikan and served as our team leader for the acoustical design of this well-known hall. In the course of our acoustical designing work for Tokyo Bunka Kaikan, we formulated the acoustical design methodology that from that time forward served as our standard approach to acoustical design projects at the NHK Technical Research Laboratories.

<< Prof. Makita's Other Achievements and His Eventual Return to Academia >>

After the completion of Tokyo Bunka Kaikan, Prof. Makita was promoted to Manager of Acoustical Department and later became Director of Broadcasting Science Laboratories of NHK. In April 1968, Prof. Makita retired from NHK.

Prof. Makita returned to the world of academia, assuming an important planning role in the establishment of a new national university, located in Kyushu, Japan's southern large island. The mission of the new national university was to find a harmonious blend between studies in the disciplines of the arts and natural sciences. The new academic institution, named Kyushu Institute of Design (Kyushu Geijutsu Koka Daigaku) opened in Fukuoka City in 1968. As a full professor at the new university, Prof. Makita taught young engineering students the subject of basic acoustics. He continued in this capacity until reaching mandatory retirement age in 1978. Many of the students he taught and inspired are now actively engaged in successful acoustical engineering and design careers of their own.

<< A Stern Mentor and His Unquenchable Thirst for Knowledge >>

Even in his 88th year, Prof. Makita's thirst for knowledge and study remain unabated. Watching his calm features as he discusses the future course of acoustical studies, I see his stern and unflinching search for the core truths that underlie complex acoustical phenomena. Each time we are together, he prods me with as-yet-unanswered topics and offers me suggestions of how to proceed in solving them. I am always humbled to admit that I have not yet found the answers to the acoustical questions and puzzles he presents to me. The direction Prof. Makita pioneered and graciously shared with me is a lifelong endeavor for me, as it is for him. I am honored to be a colleague of his and wish him many more years of good health and intellectual strength.

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Nagata Acoustics News 00-04iNo.148j
Issued : April 25, 2000

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