Quietness, Comfortable Sound and Excellent Acoustics NAGATA ACOUSTICS

News 08-12 (No.252)

Issued : December 25, 2008

[ Japanese Version ]

Seinan Gakuin University's New Chapel-a Space for Organ Music and More

by Dr. Minoru Nagata, Founder of Nagata Acoustics

New Chapel exterior
New Chapel exterior

New Chapel interior seen from the stage
New Chapel interior seen from the stage

Seinan Gakuin University, located in Fukuoka City on Japan's southern Kyushu Island, celebrated the inauguration of a new chapel on April 5, 2008, after completing construction on the building in March. The new chapel replaces the aged and deteriorated Rankin Chapel that was built in 1954 on the same site where the new chapel now stands.

The new chapel will be used by the university both as a chapel and as an auditorium. W. M. Vories & Company Architects Ichiryusha won the project's architectural design and construction management role through a design competition and Kajima Construction served as the project's general contractor.

<< A Request to Provide a Third-party Opinion >>

Nagata Acoustics' participation on this project began with a phone call I received from Ms. Toshiko Tsuji, the current owner of Tsuji Organ Builders, a Japanese company dedicated to building pipe organs that was started by her husband. When she called, in May, 2005, Ms. Tsuji words expressed both concern and urgency. She told me that the winning design for the new chapel was problematic from the perspective of how the pipe organ would sound, and she asked if I would provide a third-party opinion.

The pipe organ in Rankin Chapel was built by Ms. Tsuji's husband, Mr. Hiroshi Tsuji. The instrument has long been a well-known and loved pipe organ in Kyushu, and I can even remember attending its inaugural concert in Rankin Chapel. The new chapel's project plans included reconstructing and installing this pipe organ in the new chapel.

<< My Critique of the New Chapel's Planned Design >>

Rankin Chapel (now demolished)
Rankin Chapel (now demolished)

In the university's specifications for the new chapel's design competition, the school indicated its desire for a facility that can be used both as a chapel and as an auditorium. The winning design had an elliptical-shaped exterior and an interior with a horizontally fan-shaped audience-seating area. The ceiling height was kept to 11 m. (36 ft) and, to make the space appropriate for uses other than as a chapel, the design included a portable on-stage shell and a stage curtain that could be adapted for seminars, large lecture classes, concerts and simple theater productions. Like the placement of the Tsuji pipe organ in Rankin Chapel, the new chapel's design called for the pipe organ to be installed on an angle at stage left.

Regarding the design's basic configuration, for this kind of multipurpose use, if I wanted to prioritize the pipe organ's acoustics, it would be best to begin by using a rectangular hall shape, and then, from this basic starting point, determine how to adapt the space for multipurpose use. I shared this opinion with the university.

<< The University's Reconsideration of the Chapel's Planned Design >>

The university gave very serious consideration to my recommendation and convened an architectural committee to review the chapel's design. The ensuing debate and discussion included strong opinions about how the new design's shape would be beneficial to people expected to use the chapel, about how to achieve the target seat-count given the limitations of the project's physical site and about many other project issues.

Just counting the committee sessions that I was asked to attend, there were six sessions, and I know there were many meetings that I did not attend. At the sessions I attended, I was asked to speak about hall ceiling height and other aspects of the hall design that determine the hall's acoustics, and at these sessions, I shared my opinions and ideas. As a result of these sessions, the pipe organ's location in the new chapel was moved to the front of the room above the stage, and the hall's interior shape was revised to a rectangular configuration 21 m. (69 ft) long x 30 m. (95 ft) w. x 13 m. (43 ft) high. The new chapel seats 904 persons. Its exterior matches the red brick exterior of the campus' other buildings, and a portion of the original elliptical shape of the building exterior is preserved in the revised design.

<< Detailed Acoustical Considerations >>

The main challenge of this project's acoustical design was how to achieve both a rich acoustical environment for the chapel's pipe organ and also obtain speech clarity during sermons and lectures. Initially, I also proposed that the performance of popular music genres be included so that the chapel could be used during school festivals and on other occasions when rock music predominates. However, this use would have required the installation of retractable sidewall curtains and, unfortunately, the school did not have the funds to implement this capability.

In designing the chapel's room acoustics, I especially kept in mind two pieces of information. One point was that Rankin Chapel had a rather "dead" reverberation time of 1.6 seconds (at 500 Hz, unoccupied). The second point was that in my experience with chapels and concert halls that have pipe organs, if the room acoustics have an average sound absorptive coefficient of even 0.2, or 0.15 in a small room, and provided a suitable sound amplification system is installed, then there is no difficulty obtaining clarity of speech. Given these facts, I planned the new chapel's room acoustics to have a reverberation time of 1.8 seconds and average sound absorption coefficient of 0.19 (at 500 Hz, fully occupied).

Interior brick surfaces with protrusions and openwork
Interior brick surfaces
with protrusions and openwork

Curved and angled inward interior wall surfaces
Curved and angled inward
interior wall surfaces

To achieve the best acoustics in the chapel's interior, I requested that the sound reflecting surfaces be rigid and with sufficient mass to control any vibrations, and that the surfaces have indentations and protrusions to promote the diffusion of sound reflections. The architect selected rough-hewn white bricks which are curved and angled inward to audience for the interior wall material, and used combinations of masonry work that included protruding brick surfaces in some areas, openwork patterns in other areas to achieve both the acoustical and architectural design objectives.

For the floor of the organ balcony, Tsuji Organ specified the use of only a wood-joined platform without a concrete slab. The purpose of this design is to allow the low tones of the pipe organ to be emitted into the chapel through the organ balcony's wood platform.

We answered the need for an appropriate sound system by installing an exposed loudspeaker cluster comprised of five units of Electro-Voice FRX+640 speakers arranged in a vertical array above the chapel stage. We also installed five supporting speaker units under the balcony.

The completed hall has reverberation times (at 500 Hz) of 2.3 seconds (unoccupied) and 1.8 seconds (fully occupied, calculated based on empty hall measurements). When the pipe organ is installed, I expect that the reverberation time in the unoccupied hall will be 2.2 seconds. These reverberation times will make the hall very easy to use for its intended purposes.

<< Listening to the New Chapel's Acoustics at the Inaugural Event >>

At the inaugural ceremonies for the new chapel, the clarity of speech was fine and the sound was easy on the ear and of good quality. I enjoyed the opening event, and I am very eager to return to Fukuoka City in September, 2009, when the restored pipe organ will have been installed at the front of the new chapel.

<< Client and Project Team Appreciation >>

I want to acknowledge my gratitude to the university decision makers for their understanding and for making the tough decisions needed to revise this project's original plans. Equally, in today's difficult architectural design and construction environment, I want to thank W. M. Vories & Company Architects Ichiryusha, and specifically, Mr. Kenji Nakayama for so impeccably implementing the new chapel's acoustical requirements, as well as the Kyushu Office of Kajima Construction for their professional cooperation during the project's construction and acoustical measuring activities.

The 37th INTER-NOISE 2008 Congress in Shanghai

by Chiaki Ishiwata

A presentation session at INTER-NOISE in Shanghai
A presentation session
at INTER-NOISE in Shanghai

INTER-NOISE 2008, the International Congress and Exhibition on Noise Control Engineering, met from October 26 to 29, 2008 at the Shanghai International Convention Center. INTER-NOISE brings together professionals and experts in the field of noise and vibration control and related fields. The location of the congress, which meets annually, changes from year to year.

<< Highlights of the Congress Agenda >>

The agenda at this year's congress included presentations of more than 500 papers (including the distinguished lectures and other invited lectures), poster sessions, a panel forum on the topic of noise control engineering education in the Asia-Pacific region and so on. Each day, the presentations began at 8:30 in the morning and continued until after 6:00 p.m., with as many as 10 lectures taking place simultaneously in different meeting rooms.

The lecture sessions covered a diverse range of topics. For example, there were sessions on sound isolation and sound absorption materials, acoustical measuring methods, calculating and forecasting acoustical values, environmental noise and psychoacoustics. I was reminded of the great diversity of research and interests in this technical field that is so nonchalantly and humbly referred to as "noise control."

In keeping with China being the host country for this year's congress, one session discussed the use of micro-perforated panels, first suggested at a congress meeting in 1975 by Prof. Maa Dah-You of China's Institute of Acoustics, Academia Sinica. Also, another session presented a paper about the room acoustics of Chinese halls, focusing on Beijing's National Centre for the Performing Arts and the Shanghai Oriental Arts Center (SHOAC). In addition, I noticed that a considerable number of the presenters from European and U.S. universities and research institutions seemed to be Chinese nationals who reside overseas.

<< My Experience Lecturing on Sound Insulation in Rock Music Venues >>

I represented Nagata Acoustics at the congress and presented a lecture entitled "Sound Insulation Structure in Auditorium Buildings - Part 2: An example of the measurement results of sound insulation in a rock music performance space." The audience was keenly interested in my lecture topic and my comments because an unexpectedly large number of attendees raised their hands to ask questions during the Q&A session that followed my presentation. One of my questioners expressed surprise that seemed to border on disbelief regarding a statement I made that rock music can reach up to 130 dB of sound.

I delivered my lecture in English and the Q&A period that followed also relied on the English language as the vehicle for communications, though it was often not the native language of the person asking the question, nor is it my mother tongue. This situation made some communication during the Q&A period a challenge. At times I received assistance from some of the Japanese attendees, and I appreciated this spontaneous help.

The conference room where I delivered my lecture (shown in a photo on this page) was the largest of the rooms used for the lecture presentation sessions, but the room's screen for displaying visual material was quite small. In addition, the room's sound system was equipped solely with portable loudspeakers that were set up in a few locations along the sidewalls of the audience seating area. All of the loudspeaker units faced the audience, so that there was not even one monitor loudspeaker facing the podium for my use. During the Q&A session, questions were posed to me through a microphone that was placed in the audience seating area, but because none of the loudspeakers faced in my direction, I had much trouble hearing the questions.

Even though I am an experienced acoustical consultant who has designed the room acoustics for numerous conference spaces, delivering a lecture in the large conference space in Shanghai proved to be an extremely valuable lesson for me. I experienced first-hand the importance of loudspeaker placement in loudspeaker performance and how loudspeaker placement can affect the functionality of a conference room.

<< Impressions of Shanghai >>

Pudong New Area's night skyline
Pudong New Area's night skyline

The congress' venue-the Shanghai International Convention Center-is located in the Pudong New Area of Shanghai. This past autumn, Pudong New Area made international news headlines when the Shanghai World Financial Center completed and became the second tallest building in Asia at 492 m. (1,614 ft).

In addition to the Shanghai World Financial Center, with its unique, large, square opening built into the top floors, Pudong New Area's skyline is dotted with many skyscraper condominiums. Pudong New Area is in the midst of extremely rapid infrastructure and construction development, even by Shanghai's fast-paced standards. In Pudong New Area, the roads are wide and the buildings are either very tall or, when not so tall, very large overall. For a visitor like me from the tiny islands of Japan, the sense of being on a very large continent was palpable in Shanghai.

Visiting the Updated Vienna Musikverein's Main Hall

by Toshiko Fukuchi

Exterior of the Vienna Musikverein Building
Exterior of the Vienna Musikverein Building
(At right is the main entrance,
at left is the stage entrance.
Below the road in front of the main entrance
are the four small halls featured
in my April 2008 article in this newsletter.)

Interior of the Vienna Musikverein Main Hall
Interior of the Vienna Musikverein Main Hall

A view of the main floor from the side balcony
A view of the main floor from the side balcony

Mention the name "Vienna Musikverein Main Hall" and, beyond any doubt, the people listening to you or reading your words know you are referring to the hall that represents the world's epitome of beautiful acoustics among shoebox-shaped concert halls. Officially named the "Grosser Musikvereinssaal," this hall is sometimes called the "Golden Hall" because of its sumptuous gilded interior. This past January, in connection with one of our client's projects, I had the pleasure of returning to the Musikverein Main Hall to take a tour of the hall and enjoy a concert.

The Vienna Musikverein website offers visitors to the site the option of browsing its pages in German, English or Japanese. The Japanese-language option hints at the ardent following this hall has among Japanese classical music fans. On the evening when I attended a concert at the hall, Maestro Fabio Luisi conducted the Vienna Philharmonic Orchestra in a program of Rinehart Strauss' "Don Quixote" and Brahms' First Symphony. As I waited for the concert to begin, I could not help but notice the large number of Japanese patrons in the audience.

Mr. Stefan Billing, Manager of the Musikverein's Technical Department and an employee of the institution for 25 years, gave me a tour of the Main Hall and the Musikverein's new small halls. He shared a wealth of information with me and, in this article, I will pass on to our readers some of the main hall's recent developments that are interesting from an acoustical and cultural perspective.

<< The Main Hall's Updated HVAC System >>

In May, 1992, I visited the Vienna Musikverein while on a study tour with colleagues from Nagata Acoustics. For three evenings in succession, I attended concerts in the Main Hall. At the time, the Main Hall lacked an air conditioning system. Even though the month was May-and therefore, it was not yet summer-I was overwhelmed by the stifling air in the hall.

This time, my visit took place during winter. I mentioned my previous, late-spring experience to Mr. Billing, and he explained that about 10 years ago a cooling and heating system was installed in the main hall. I also told Mr. Billing that I remembered sitting on one of the balcony's un-upholstered wood seats. He told me that two or three years ago cushioned upholstery was added to the balcony seating. Now all patrons can enjoy the hall's concerts in comfortable seating and pleasant ambient surroundings throughout the year.

<< Inside the Main Hall >>

Tapestries hang over banisters at the side of the main hall's main-floor seating
Tapestries hang over banisters
at the side of the main hall's main-floor seating

Other than the upholstery on the main hall's seats, the only sound-absorbing materials in the main hall are the tapestries that hang over banisters at the side of the main hall. The placement of tapestries over these banisters dates back to the original completion of the hall in 1870. Backhausen Textiles, a Viennese company, wove the tapestries currently in use. They have adorned the hall for some 40 years.

Readers who have attended a New Year's concert at the Musikverein or watched one on TV know that for this famous annual event audience seats line even the sides of the hall's performance stage. However, the main hall's stage has a depth of just 10 m (39 ft), a constrained space for some orchestra configurations. Because the stage does not provide sufficient room to seat all the players needed for orchestral works with very large configurations, the first three-to-five rows of orchestra seating can be removed and the stage extended to accommodate very large orchestra configurations. At one event, a record 700 performers are said to have been on the main hall's stage at the same time and another momentous event had three orchestras seated on the stage simultaneously. The hall seats up to 1,680 patrons, so these huge extravaganzas must have been incredibly spectacular.

<< An Extraordinary Cloak Room for Concert Patrons and Gala Balls >>

Vienna is famous for its gala balls and the Musikverein ranks as one of the most prestigious venues for these events. The Musikverein hosts two balls every year. To accommodate the large numbers of people who attend the balls, the Musikverein has a cloak room that can hold the outerwear of 3,500 persons.

When I attended a concert in the main hall this past January, the area near the cloak rooms was full of people both before and after the concert. Despite the many patrons moving in different directions with coats and hats in hand, amazingly little time was needed to check or retrieve a coat. Clearly, the cloak room attendants follow organized procedures that enable them to service hundreds, even thousands of patrons fast and efficiently.

When seated in the main hall, I realized that the audience seats do not have extra leg room and patrons sit straight up in the narrow rows of seats. In Japan, patrons often fold their coats and place them on their laps throughout entire concerts. Here, it would be impossible to prop a folded heavy winter coat on one's lap for an entire concert without impinging on the space of other patrons to the left and right.

Cloak room in the main lobby
Cloak room in the main lobby

Last January, on the day we arrived in Vienna a cold spell lifted and the city greeted us with unseasonably warm weather. Nevertheless, I know that Vienna's cold winters require residents to don heavy outer garments. Experiencing the Musikverein surrounded by patrons in winter attire I understood that the hall's extraordinary cloak room is a truly essential part of the Vienna Musikverein. The Musikverein's HVAC system may be a 21st century addition, but the cloak room shows that this hall has a long tradition of prioritizing the practical convenience that best allows patrons to enjoy its magnificent concerts, regardless of the vicissitudes of climate and weather outside.

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

(LA Office)
2130 Sawtelle Blvd., Suite 307A
Los Angeles, CA 90025, U.S.A.
Tel: +1-310-231-7818, Fax: +1-310-231-7816

(Paris Office)
75, avenue Parmentier
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 ]