Acoustic Project

About

The Concept

Who Benefits

Science and Art of Acoustics

About

The goal of the Acoustic Project is to renovate and upgrade the acoustics within the Evangeline Atwood Concert Hall and the Discovery Theatre.

Twenty-five years ago the Center opened allowing musicians, singers, actors and dancers a world class facility in which to perform and patrons a spectacular facility in which to enjoy the arts. But, the acoustic enclosure (shell) used in the Atwood Hall was actually designed and built for the Discovery Theatre. Because of budget restraints the shell was modified and has been used in the Atwood all of these years. The shell does not fit the Atwood either acoustically or visually.

During the 13-14 season, the Center celebrated its 25th Anniversary. We marked this milestone in many ways, concluding the year long celebration with the unveiling of the new acoustic renovations and upgrades in the Atwood Hall with a truly memorable performance of classical music featuring Olga Kern and the Anchorage Symphony Orchestra Fall 2014.


This project will have significant impact for thousands of people both musicians and patrons alike for many years to come.

Did you know?

When the Center opened in 1988, the acoustic shell originally designed for the Discovery Theatre was instead installed in the Atwood Hall as a cost-saving measure. At the time, it was expected to only be a temporary solution. The shell is a lightweight design and was adapted to fit the large Atwood stage by adding vertical panels. The Atwood Hall was designed like most other halls of the time with acoustic treatments and orchestra enclosures that allowed the sound to move through the shell and then reflect back towards the audience. Since then, the science and art of acoustics have evolved to directional movement which allows musicians, singers, and patrons to hear better with much less diffusion.

A Gift of Beautiful Music to our community!

This much needed Acoustic Project has allowed the hundreds of musicians and singers who perform at the Center to hear themselves better and, in turn, improve their performance. The new, heavier shell will also help to eliminate the "dead" spots that currently plague the Atwood Hall helping to ensure that the audience will better hear and experience everything that occurs on stage.


 

The Concept

The overall concept of this project was to design and install a new, more acoustically supportive shell for the Atwood Hall and to replace rigging and electrical services and equipment that are required to accommodate the new shell. The proscenium zone which is now acoustically transparent will be clad from behind with reflective material so that sound is transmitted out of the stage enclosure into the audience chamber. At the same time, the shell currently in the Atwood Hall has been restored to the Discovery, where it was originally intended to be, and the rigging, storage and electrical systems updated to accommodate this shell without reducing the functionality of the Discovery Theatre stage. This will require a storage rigging system for the towers along the upstage wall.


In the photo above, you see the dramatic offset between the old shell walls and ceiling around the orchestra enclosure to the ceiling of the house of Atwood Hall. The new orchestra enclosure reaches higher and wider to more closely transition into the house (seating area). In unamplified music performance, it is ultimately the intent of the orchestra enclosure to make a concert hall or theatre into "one room." Previously in the Center, the orchestra enclosure did not accomplish this goal. The old proscenium zone in both spaces provided for access for lighting and sound equipment and did not include the need for supportive acoustical surfaces. That situation left a fundamental gap between the stage and the house which further limited the goal of creating "one room" visually, as well as acoustically.


The above rendering of the new acoustic enclosure in the Atwood Hall illustrates how the "one room" concept can be achieved with an appropriate acoustic enclosure. Notice the way the shell takes full advantage of the opening into the auditorium minimizing the offset between the shell itself and the ceiling outside. A properly designed acoustic enclosure was a goal of this project.


 

Who Benefits!

The Anchorage Symphony Orchestra (including Young People's Concerts), Anchorage Youth Symphony (three orchestras), Anchorage Concert Chorus, Anchorage Concert Association (specifically unamplified music presentations) and Anchorage Opera all present or have presented unamplified music presentations in the Atwood Hall. Combined, these presenters offer approximately 20 performances a season featuring hundreds of musicians and singers (both youth and adult) to an estimated 40,000 people a year. It has long been understood by musicians and singers that the acoustics in the Atwood Hall are in need of improvement.

Sherri Burkhart Reddick, Executive Director of the Anchorage Symphony Orchestra said

"We believe the new shell will ensure that the audiences will better hear and experience everything that occurs on stage. It will enable musicians to hear each other better and heighten their performances."
 

The Science and Art of Acoustics

Evaluations conducted in 2010 by acoustician Scott Pfeiffer of Threshold Acoustics involved user interviews with musicians and patrons, extensive critical listening in rehearsal and performance, and acoustic measurements of the existing hall with and without the current orchestra shell. Deficiencies identified in the use of the room for unamplified music performance established the need for an improved orchestra enclosure and renovations to the proscenium zone of the stage. Expected outcomes from this renovation project include:

  • Improved hearing conditions for musicians on stage;
  • Dramatically increased presence of unamplified sound heard in the audience;
  • Increased reverberation time and clarity as heard by musicians on stage and audience throughout the house.

These outcomes will be verified through a repeat of the evaluation process during the commissioning (tuning) of the new orchestra acoustic enclosure. User interviews, critical listening by the acoustic consulting team and acoustic measurements will be utilized in confirming the success of the effort.

The new acoustic enclosures will be "tuned" in the summer of 2014. The tuning will allow engineers and acousticians to evaluate and refine the quality of the sound of the enclosures. Musicians from Anchorage Youth Symphony will perform free concerts (open to the public) for that purpose. The new Atwood Hall and Discovery converted acoustic enclosures will provide significantly better acoustics, once the projects are complete. Below is an example of measurable results (drawings by Threshold Acoustics).


The current Atwood proscenium surround is transparent and does not provide any supportive reflections. The illustration to the left shows a dot at center stage indicating one place on stage from which sound reflects. The first useful horizontal reflections come from the side walls, a quarter to a third of the way into the audience chamber. As a result, a significant number of seats are outside of the zone of reflected sound, indicating the stage surround is not able to provide good reflective surfaces for the center orchestra seating.

Acoustic reach with new proscenium fill The most effective way to eliminate the apparent dead zone at the center of the orchestra seating would be to provide a new reflective surface behind the acoustically transparent proscenium surround. Image A3 shows a reflection diagram with a solid, reflective surface added to the proscenium surround. The surface's resulting reflection pattern is shown in blue. Notice that the unobstructed coverage pattern for the orchestra level's center section has been greatly increased.



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