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

Nagata Acoustics News 04-12 (No.204)
Issued : December 25, 2004

Tokyo's Shinanomachi Church Dedicates New Building

by Masaya Uchida

In June 2004, Shinanomachi Church, a member of the United Church of Christ in Japan, marked its 80th anniversary of ministry work. In July, the church's new building completed its construction and, on September 26, 2004, the congregation dedicated the new facility and moved into its new home. The church is located in Tokyo's Shinjuku Ward.

The new building replaces the church's first structure, built in 1930 and designed by Japanese architect Shinichiro Okada. Mr. Okada also designed two other Tokyo architectural landmarks, the Kabukiza Theater and the historic Meiji Seimei Building. Like the Meiji Seimei Building, the first Shinanomachi Church exemplified and helped define Japan's Western-style architecture of the early modern era. Its sanctuary occupied the second and third floors of the building.

The original church structure served the congregation for 73 years and the congregation had a strong attachment to the old building. But the old building would have been difficult to seismically retrofit for earthquake safety, and it required other costly maintenance and repairs arising from the building's age and normal wear-and-tear, so the congregation decided to build a new church building.

<< The New Main Sanctuary and Project Overview >>

Inside view of the chapel
The design of the new church building's main sanctuary uses an octagonal-shaped footprint and has a three-story-high ceiling. In addition to this main worship hall, the south and west sides of the church building's first and second floors house a small chapel, a social hall and support rooms. The church entrance faces west onto the well-traveled city artery of Gaien Higashi Dori and a rectangular entrance hall provides a straight-line view from the main entrance through the main sanctuary to the sanctuary's altar. In addition, the entrance hall's exposed, peaked roof uses large glass skylight panes to bring abundant natural light into this spacious vestibule, creating an almost outdoors ambience that connects and bridges the transition from the world of the city outside the church doors to the serenity of the worship hall space inside.

The main sanctuary's altar is nestled in one corner of the octagonal-shaped room, with fixed seating for about 200 congregants placed in concentric, curved rows, filling the nave to the rear of the main sanctuary. The interior lighting from both the walls and ceiling of the sanctuary provides a soft glow and creates an intimate and calm atmosphere.

Mr. Shozo Uchii and Uchii Architects designed the new Shinanomachi Church building. Architect Uchii's passing is still of recent memory, occurring while the Shinanomachi Church project was under construction and making this structure his architectural swan song. Toda Construction Company's Tokyo Division served as the project's general contractor. Yamaha Sound Technologies, Inc. was responsible for the installation of the sound system and audio-visual system construction.

<< The Main Sanctuary's Acoustical Design >>

Worship hall acoustical design planning typically defines the following two objectives as the desired acoustical goals:

1. The ability of congregants to clearly hear sermons, and

2. Rich sound quality for hymns and organ music.

To obtain the first of these objectives, an acoustical design that creates a short reverberation time will produce the desired result, while for the second of these objectives, a long reverberation time is needed, exactly the opposite of the acoustical characteristics required for the first objective.

Regarding these mutually competing objectives, the church building committee assigned the highest priority to the ability to clearly hear sermons. In addition, to realize the musical potential of the new pipe organ that the church plans to install and the congregation's singing of hymns, the building committee asked that the reverberation time be made as long as could possibly be achieved without compromising the clarity of the sermons.

The main sanctuary's sound system played a key role in our approach to achieving the two acoustical goals set for us by the client. Therefore, we designed some elements of the sound system as predecessor work to setting the reverberation time objective and planning the interior finishings of the main sanctuary.

At the wall behind the altar, we installed sound-absorbing material to prevent amplified sound from bouncing off this surface and producing acoustical feedback (also known as howling). Likewise, we also installed sound-absorbing material along the rear wall of the main sanctuary to prevent echoes and other undesirable sound phenomena due to sound from loudspeakers reflecting off this surface. Since our targeted reverberation time for the space necessitated more sound absorption than these measures would provide, we also finished a portion of the main sanctuary's side walls with sound absorbing surfaces. As a further reverberation control measure, we covered the nave's pews with fabric upholstery to prevent the room's reverberation time from becoming excessively long when there are a small number of congregants in the sanctuary.

The walls and ceiling of the main sanctuary are drywall surfaces (except for the aforementioned portions of the wall that are sound-absorbing). To provide ample sound reflections and to prevent the drywall from producing fret-buzz-like vibration noise when the organ is played, we specified multi-layer construction for the drywall sections of the walls and the ceiling. Additionally, we designed the wall surfaces to have wide and narrow ribbed surfaces to promote sound diffusion.

The main sanctuary's reverberation time (measured at 500 Hz) is 1.8 seconds when the space is unoccupied and 1.4 seconds when occupied to maximum seating capacity.

<< The Main Sanctuary's Sound System Design >>

Fig.1 EDT and D50 measured by Line-array
and Omni-directional loudspeakers
>> Loudspeaker Selection

For the main loudspeakers at the sanctuary altar, we chose compact line-array speakers with narrow vertical coverage. This choice enabled us to control the angle of sound emitting from the loudspeaker so that the sound does not radiate to areas other than the intended congregational seating. The line-array loudspeakers also minimize the potential for excitation of reverberations in the sanctuary.

These benefits of the line-array loudspeakers combine to enable us to obtain speech clarity for sermons under a comparatively long reverberant condition. We located the main loudspeakers in the walls on each of the two sides of the sanctuary's altar so that the sermons amplified by the loudspeakers will be heard by the congregation as projected from the altar and the congregation's attention will be directed towards the altar.

>> Acoustical Parameter Measurements

STI (Speech Transmission Index): Using the microphones we installed at the sermon podium and the celebrant's podium, speech delivered through the sanctuary sound system obtains an STI measurement in the range of 0.56-to-0.68 (a rating of fair-to-good). In addition, I confirmed through listening validation that, compared to the reverberation time of hymns and organ music in the hall, when the line-array loudspeakers amplify speech, the room's reverberation for the amplified speech is appropriately modulated.

Regarding the acoustical comparison of hymns and organ music to sermons delivered through the line-array loudspeakers, we used omni-directional loudspeakers to simulate the hymns and organ in the sanctuary and obtained the following measurements for EDT and D50 objective physical parameters.

EDT (Early Decay Time): The EDT value is reported to be more clearly correlated to subjective reverberance rather than the reverberation time. As shown in the upper graph of Figure 1, the line-array loudspeakers' EDT measurement for frequencies above 1,000 Hz is as much as 0.3 seconds shorter than the EDT of the omni-directional loudspeakers. This means that the speech amplified through the line-array loudspeakers would be subjectively less reverberant than live hymns and organ music.

D50 (Definition or early to total sound energy ratio): As shown in the lower graph of Figure 1, the D50 ratio for the line-array loudspeakers measures higher than 0.7 for frequencies of 1,000 Hz and above, a considerably higher ratio than 0.5, the measure for sufficient speech intelligibility. By comparing the line-array loudspeakers' high D50 ratio with the D50 value for omni-directional loudspeakers, we can see the line-array loudspeakers improve the clarity of amplified speech.

<< New Church Sanctuary Dedication Concert >>

The Shinanomachi Church congregation celebrated the completion of their new home with a Dedication and Concert event held in October. Among the musical fare on the program were performances by the Shinanomachi Church Choir and a cello solo. The choir's harmonies sounded majestic and the sermon could be heard clearly and had a natural-sounding quality. I am confident that the new space meets the requirements, hopes and expectations of the Shinanomachi Church community.

<< New Pipe Organ Plans >>

Shinanomachi Church gave the pipe organ it used in its previous building to Sukagawa Church in Fukushima Prefecture. That organ is a 1982, 7-stop organ built by Köberle Ogrelbaumeister of Germany. For the time being, Shinanomachi Church has revived the use of the reed organ that it used from 1932 to 1981. The church ordered a new pipe organ from the Dutch organ builder GEBR. REIL. The new pipe organ is currently being built in Holland and is scheduled to be installed in the church sanctuary in June 2005. Together with the church community, I look forward to the new pipe organ's addition to the Shinanomachi Church main sanctuary.

Shinanomachi Church can be contacted by telephone at +81-3-3351-4805 and has a website (in Japanese only) at http://www.shinanomachi-c.jp/.

Sony Chairman Emeritus Donates Karuizawa Ohga Hall to Town

by Dr. Keiji Oguchi

Completion Ceremony
From the left, Mr.Umeda,
Mrs.&Mr.Ohga and Mr. Sato
(photo:Kajima Co.)
Sony Chairman Emeritus Mr. Norio Ohga applied his retirement package to the construction of Karuizawa Ohga Hall in Nagano Prefecture's Karuizawa, a scenic vacation and "get-away" destination especially popular during the summertime, when it offers cool and woodsy relief from the Tokyo heat. On December 5, 2004, with the hall construction complete, Mr. Ohga and other dignitaries held a Completion Ceremony and Mr. and Mrs. Ohga officially presented the hall to the town of Karuizawa. First, Mr. Sadao Umeda, CEO and President of Kajima Corporation, the company that designed and built the hall, gave the deed and keys of the completed hall to Mr. Ohga, then Mr. Ohga, in turn, gave the deed and keys to Mr. Masayoshi Sato, the mayor of Karuizawa. We were pleased to attend the ceremony, as we participated on the project as consultants to Kajima Corporation.

The Completion Ceremony program included a speech by Mr. Ohga, in which he explained why he decided to build and donate a concert hall to the town of Karuizawa. Mr. Ohga recounted that during World War II, a number of Japan's piano teachers moved to Karuizawa to escape the bombing of the major cities. His wife, Mrs. Midori Ohga was a young girl in those days, and she also had been sent away from the cities and was staying in the Nagano town of Suwa. In order to study piano with the teachers in Karuizawa, she would make the trek from Suwa to Karuizawa for her piano lessons. Mrs. Ohga's childhood memories led her to persuade her husband to build and donate Karuizawa Ohga Hall.

After the ceremony in the hall, Mr. Ohga held a press conference and met with reporters. At the press conference, he shared his hopes that the people of Karuizawa will exercise wisdom and creativity in their use of the new hall.

Celebration Concert
Symphonia Finlandia conducted
by Patrick Gallois (photo:Kajima Co.)
Immediately following the completion ceremony, the town of Karuizawa performed a demonstration concert to give the local townspeople the opportunity to experience a concert in the new hall. The plan of the hall has a pentagonal shape, implementing a concept suggested by Mr. Ohga. The first floor seating of the hall has fixed seating for an audience of 660, and the five sides that surround the first-floor seating have gallery boxes where a combined capacity of up to 140 persons can stand and view performances.

Maestro Patrick Gallois conducted the chamber orchestra Symphonia Finlandia to a full house for the demonstration concert. Mr. Ohga changed his seat during the intermission to experience the acoustics from different locations. After the concert, he told us that the acoustical characteristics are fine and that he was glad that he chose the pentagonal shape for the hall. "At the back of the hall and the front of the hall, even in the rear of the first floor at the corridor, the acoustics all sound the same," he said. When everyone who was engaged in the hall's design and implementation heard Mr. Ohga's evaluation, we felt the satisfaction of having met our client's expectations.

Karuizawa Ohga Hall is now in a period of opening preparations and will hold its official opening in the spring during Japan's end-of-April "Golden Week" national holidays. To foster the arts appreciation and creative inspiration of the people of Karuizawa, Tokyo Philharmonic Orchestra has entered into a contract with the city to perform in the hall and to support the musical activities of Karuizawa, and the city looks forward to expanding its cultural opportunities thanks to the new Karuizawa Ohga Hall. I will share more about this hall's acoustics in a future News & Opinions Issue, after the hall's official opening.

Nagata Acoustics Will Design the Acoustics of Hamburg's New Concert Hall

by Yasuhisa Toyota

The city of Hamburg, Germany recently named Nagata Acoustics as the acoustical design consultant for the city's new concert hall. The new hall will be built in the city's harbor district along the Elbe River, where a number of revitalization and redevelopment projects are currently underway. The new concert hall will be constructed as a significant addition to the top of an existing building formerly used as a warehouse. (The architectural rendering shown here is courtesy of Herzog and de Meuron.)


The city of Hamburg was the birthplace of two of Germany's most well known composers, Brahms and Mendelssohn, and continues to hold a prominent and influential position in today's classical music world. The new concert hall in this city will surely receive worldwide attention and scrutiny. We are both honored to be selected as the acoustician and aware of the significant responsibility we will assume.

The new hall's architect is the Swiss firm of Herzog and de Meuron, based in Basel. Jacques Herzog and Pierre de Meuron are perhaps best known for their design of the Tate Modern Museum of Art in London, for which they received the Pritzker Prize in 2001. (The Pritzker Prize is the world's most esteemed architectural award, sometimes referred to as architecture's Nobel Prize.)

<< Selection Schedule of Key Project Participants >>

Herzog and de Meuron were selected as the project architect in 2001. Since then, the city of Hamburg, which is the project's sponsoring body, and the architect have been engaged in the project's programming phase to determine the scope and other characteristics of the project.

In 2004, the project entered its design phase, including selection of the acoustical design consultant, the theater design consultant and other consultants identified as required for the concert hall project. The process for acoustical design consultant selection began with a "short list" of acoustical consulting firms from several countries. The sponsor and the architects invited these firms to submit proposals and interviews process. Nagata Acoustics was finally selected as the acoustician of the project, and simultaneously "dUCKS sceno", French, Lyon-based firm was selected as the theater design consultant.

<< Project Scope Overview >>

The planned concert hall will have a large hall with a 2,200-to-2,400-seat capacity. It will be designed for the performance of classical music, focusing primarily on orchestral music. A 500-seat small hall is also planned. The decision of whether the small hall will be a multipurpose hall or also a classical music concert hall is still under discussion. In addition to the large and small hall, the site's programming includes plans for a hotel to also be built as part of the overall project.

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Nagata Acoustics News 04-12 (No.204)
Issued : December 25, 2004

Nagata Acoustics Inc.
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