News 16-04 (No.340)
Issued : April 25, 2016
Chapman University’s Musco Center for the Arts Opens in Orange County, California
By Motoo Komoda
In our November, 2012 newsletter I wrote about the start of construction on Chapman University’s Musco Center for the Arts. The center is located on the university’s campus in Southern California’s Orange County. After 3.5 years of construction, the center celebrated its grand opening on March 19, 2016.
<< Project Overview >>
The new center has indoor space of 8,189 sq. m. (88,142 sq. ft) and cost about US$82 million to build. In addition to a world-class, 1,044-seat multipurpose hall, the center has 9 dressing rooms, a recording studio and a conference room as well as a host of other features and amenities.
The center’s multipurpose main hall bears the name Julianne Argyros Orchestra Hall. With its large stage, fly tower, concert hall-quality sound reflection panel system, an orchestra pit that can accommodate 70 musicians and a proscenium-style stage, this hall fulfills the design intent of a multipurpose theatre that can adapt to the performance needs of many genres.
Both the project architect—Pfeiffer Partners Architects—and the theatre consultant—Theatre Projects Consultants—are firms with strong previous experience in the design of halls and theatres. As the team worked on addressing the project’s various constraints, the representatives of each of these two firms brought to the table various lessons learned on previous projects and views informed by previous experiences. I found it very rewarding to collaborate in the decision-making process with team members who could both articulate and lobby in favor of a strongly held idea or principle and also listen to the fact-based input of other team experts.
<< The Design Concept of Continuity and Intimacy in Julianne Argyros Orchestra Hall >>
From the very beginning of our work, the project team collectively prioritized the design concept of visual continuity and a feeling of intimacy between the stage and the audience. The hall has a hexagonally-shaped footprint, with main floor audience seating, 2 tiers of balconies at the rear of the hall and 16 loge boxes at the sides of the stage. This configuration brings the audience very close to the stage. A straight line from the tip of the front of the stage to the top row of the center balcony seating measures just 29 m. (97 ft), a proximity that combines with the perspective effect of the hall’s shape to make the audience feel quite close to the stage indeed.
The hall has a sound reflection panel system that we designed to acoustically provide appropriate reflections for classical music performances and also to visually contribute to the feeling of continuity between audience and stage. To achieve these acoustic and visual objectives, we created an ingenious design of double layers of eaves that connect to the side balconies. The weight of the reflection panel system is not trivial. When combined with the hall’s steel frame and equipment for lighting, these elements have a total weight of 55,000 kg (120,000 pounds).
The proscenium opening measures 19 m. (62 ft) wide by 11 m. (36 ft) high. For large-scale orchestra performances, the size of the stage area can be increased by raising the floor of the orchestra pit to the same height as the stage floor. In this configuration the stage and the orchestra protrude into the audience seating area, further increasing the sense of proximity and intimacy between audience and performers.
<< Adaptable Acoustics for Non-Amplified and Amplified Performance >>
The hall’s programming included use of the hall for amplified events in addition to non-amplified classical music concerts. To adapt the hall’s sound reverberation characteristic for performances that use electro-acoustic equipment, we installed a large number of motorized, sound-absorbing curtains. On the side walls of the hall, the curtains can be unfurled like banners from between the petal-shaped, three-dimensional wall elements. On the ceiling, the curtains can be deployed horizontally along lighting bridges. Each banner and curtain can be separately deployed and retracted at the touch of a button. The system makes it possible to customize the hall’s reverberation characteristic to suit specific performance needs.
When the sound reflection panel system is in use, the hall’s longest possible sound reverberation time is 2.1 seconds. (This value is calculated for a full hall based on measuring the empty hall at 500 Hz.) The shortest sound reverberation time that can be achieved is 1.4 seconds (calculated value for a full hall as above). The short reverberation time configuration can be set up by storing away the sound reflection panel system and using both the proscenium curtain and all of the sound-absorbing side wall banners and ceiling curtains. The hall’s acoustical design obtained great flexibility in customizing the sound reverberation time to meet the needs of diverse events and performances. We fully succeeded in achieving the client’s programming goal of a multipurpose hall.
<< Inaugural Gala, First Classical Music Concert and the Hall’s Bright Future >>
On March 19 2016, the opening gala event featured the Los Angeles Opera Orchestra and star soloists Placido Domingo, Deborah Voigt and Milena Kitic. They were joined by numerous graduates of the university and performed one after another of opera arias, delighting the audience and delivering a truly star-studded and spectacular inaugural concert.
On April 2, Pacific Symphony performed a program of Grieg’s Piano Concerto, featuring pianist Grace Fong, and Beethoven's Symphony No. 5. Through my impressions from the evening of opera arias and the Pacific Symphony’s performance, I confirmed that we achieved our acoustical goals for this new venue.
In the future, the hall will hopefully be used both as an educational facility within Chapman University and to deepen cooperation with regional performing arts organizations, helping to foster the performing arts and bring increased performance opportunities for community audiences to attend. For more information about the Musco Center for the Performing Arts at Chapman University please consult the center’s website: http://muscocenter.org
Delving into the Details—Operable Partition Walls—Part 2: How to Obtain Effective Sound Isolation
By Ayako Hakozaki
In Part 1 of this series I discussed how to understand the numeric values of sound isolation performance tests that are reported in the product literature provided by partition wall manufacturers. This time, to help you obtain the desired sound isolation performance from an operable partition wall, I will share considerations to keep in mind regarding conditions above, below and at the sides of the operable partition wall.
<< How to Prevent Sound from Leaking via a Ceiling >>
Example of a Sound Isolation Wall Installed Above a Suspended Ceiling
Example of a Partition Wall Rail Hidden by Metal Casing Below the Plane of the Ceiling
The first factor that I will discuss is the ceiling above the operable partition wall. In general, if the partition panels are installed in spaces that have suspended ceilings, the suspended ceilings are often made of a layer of drywall and a layer of acoustical tile attached below the drywall. In this situation, it is important that sound be prevented from being transmitted through the ceiling from one room to an adjacent room. The prevention method is to install a vertical wall above the operable partition wall. The specification for the material of the vertical wall should be determined by the level of sound isolation performance desired from the operable partition walls being installed between the rooms. If the partition walls are sound isolating then the wall above the ceiling will typically have 2 double layers of drywall separated by an air space. Depending on the sound isolation performance specification, glass wool may be inserted between the 2 drywall layers.
While in standard implementations the rail of the operable partition is recessed into the suspended ceiling and the sound isolation wall built above the rail, in situations where the rail is installed on a ceiling that does not have a drop ceiling or where the operable partitions are attached to the pipes of a visible, openwork grid system, it becomes important to ensure that the way the rail is installed prevents the joint between the rail and the ceiling from becoming a weak location from the sound isolation perspective. Similarly, if the air space above a suspended ceiling contains ducts or other conduits, it is necessary to remember to also add sound isolating material to these elements to prevent their becoming transmitters of sound between rooms.
<< Sound Isolation at the Opening of an Operable Partition Wall >>
Opening Frame at a Sound Isolating Wall
The opening against which an operable partition wall closes is another location of concern for sound isolation performance. The same level of sound isolation performance must be applied to the frame of the opening as to the sound isolation wall that is perpendicular to the operable partition wall and the operable partition wall. In addition, if the interior is finished with a sound absorbing material, the wall behind it should also have sound-isolating properties.
<< Floor Systems that Require Attention >>
Example of a Concrete Floating floor and Wood Support Assembly
The floor under an operable partition wall system may be one of several types. One type is a finish floor attached directly to a concrete slab. Another type is a finish floor set on layers of plywood or other substrates or on a wood support assembly or sleepers that result in an air space between the finish floor and the concrete slab. A third type is a finish floor on a concrete floating floor with an anti-vibration and sound-isolating system.
To close gaps between an operable partition wall and a finish floor, sliding pressure mechanisms can be used. However, if the surface of the floor is not smooth, the pressure mechanisms alone cannot completely eliminate gaps. In particular, when the finish floor will be attached directly to a concrete slab or to a floating floor, care should be taken to have smooth surface floors directly below the operable partition wall so that gaps can be eliminated.
When the floor is set on plywood layers, a wood support assembly or sleepers, a situation occurs that is similar to that of having a suspended ceiling because sound can travel through the air space below the floor and care must be taken to prevent this. The prevention method depends on the specifications of both the operable partition and the floor. One example is shown in the accompanying diagram of a concrete floating floor and a wood support assembly where an upturn beam is added to prevent a gap between the operable partition wall and the finish floor surface.
In addition, in the case of concrete floating floors, solid borne sound can be transmitted via the floating floor. I have encountered real-life examples of solid borne sound transmission affecting the sound isolation performance of a space. In implementations where a high level of sound isolation is required between 2 adjacent spaces such that double layers of operable partition walls are specified, or even if a single layer operable partition wall is specified with a high level of sound isolation performance, we introduce a separation in the floating floor directly below the partition wall location. In this way we eliminate the possibility of solid borne sound transmission via the concrete floating floor.
<< Sound Leaks Related to the Storage Set Up of Operable Partition Walls >>
When a separate storage room is planned for operable partition walls, this storage space is sometimes combined with storage space used for other purposes. While the operable partition wall is in use, if the storage room can be accessed from either of the adjacent rooms that are separated by the operable partition wall, it is essential to give the doors between the storage space and each of the rooms a sufficient level of soundproofing specification such that sound cannot leak from one room into the storage room and then from the storage room to the adjacent room.
(The swing doors into the space for the operable partition wall storage and the swing doors on the other
side of the partition wall that open into the storage space create a pathway for sound to travel.)
<< Can Sound Leak via the Rail? >>
Example of a T-Intersection of Rails for Operable Partition Walls
(The intersection is shown by the white circle.)
One topic typically raised when considering operable partition walls and sound isolation between adjacent rooms is whether the rail can lessen the effectiveness of the sound isolation. The path the rail traverses of course depends on the space that needs to be partitioned. However, depending on the storage location of the panels, a rail may be installed in a way that it traverses or comes to a T-intersection with another rail. In this case, an opening is created that will enable sound to leak between the adjacent rooms and negatively impact the sound isolation performance. In situations where a high level of sound isolation performance is a priority, it is highly desirable that there be no perpendicular interruptions to the rail.
To obtain the desired and expected sound isolation performance from an operable partition wall system installation, in addition to selecting the appropriate partition wall system, consideration must be given to the conditions of the spaces above, below and to the sides of the installed system. I hope that the above discussion provides helpful information to readers who may be considering installing a sound isolating operable partition wall system.
Nagata Acoustics Inc.
Hongo Segawa Bldg. 3F, 2-35-10 Hongo
Bunkyo-ku, Tokyo 113-0033, Japan
Tel: +81-3-5800-2671, Fax: +81-3-5800-2672
1990 S. Bundy Drive, Suite 795
Los Angeles, CA 90025
Tel: +1-310-231-7878, Fax: +1-310-231-7816
75, avenue Parmentier
Tel: +33 (0)1 40 21 44 25, Fax: +33 (0)1 40 21 24 00