Achieving superior acoustics at Dayton, Ohio’s Kroc Community Center.

In May of this year, The Salvation Army cut the ribbon on its newest Kroc Community Center campus, located in Dayton, Ohio. Designed by the team of John Poe Architects, Korda/Nemeth Engineering and Vivian Llambi & Associates, and headed by Architect Ken Ratieri, the project presented several acoustics challenges, which were solved using some unique wall and ceiling designs.

At the dedication, Major Tom Duperree told the crowd, “During her life, Joan Kroc [heiress to the McDonald’s fast food chain fortune] supplied the funds for The Salvation Army to build a state-of-the-art community center in her hometown of San Diego. She wanted the underprivileged and underserved members of her community to experience some of the same amenities of life she was afforded. And what a magnificent facility it is. A true sight to behold! Her hope was to identify cities all across America which would benefit by having similar centers in their communities. But she died all too soon and, upon her passing, she bequeathed The Salvation Army in America an unprecedented gift-the largest, single gift ever made to an organization in our country, if not the entire world!”

According to The Salvation Army, the $1.5 billion bequest stipulates that the funds be used for the construction and operation of state-of-the-art community centers across the country. Dayton was one of eight cities selected in the Army’s Eastern Territory, and has received $69 million from the estate. Adding over $7 million in local private donations, about half of the total was spent on construction of the campus. The balance is reserved for operations.

After the dedication, visitors toured the 17-acre campus. The campus includes the restored Duncarrick Mansion, the Recreation Building, the Worship and Arts Building and the Education Building.

KENNEDY MANSION

Duncarrick (Gaelic for “Home of the Kennedys”) was originally designed by Peters, Burns and Pretzinger in the 1890’s for Grafton C. Kennedy. The mansion is listed on the National Register of Historic Places. It now houses administrative offices, a welcome center, a board room, meeting rooms and a museum of Old North Dayton.

The Recreation Building includes a 400-seat indoor basketball court, which is used for city youth basketball leagues, a fitness center filled with weight and aerobic training equipment, a walking track, concessions and locker rooms equipped with showers. Just outside the recreation building is a 400-seat outdoor basketball court, complete with JumboTron scoreboard, which is used for league play and summer tournaments for Dayton area youth.

The Education Building contains the Family Learning Center, Early Childhood Resource Center and the Technology Café. The café includes a WiFi gathering space, a technology learning lab and a coffee and snack shop. The oval-shaped space also features a large video display wall flanked by two Wii stations for game play. 

ACOUSTICAL CONSIDERATIONS

A major acoustics challenge in this and all buildings on campus was to achieve low background noise. This was a particularly difficult challenge as the congested Interstate I-75 hugs the west border of the campus. As a first step in designing walls and ceilings to block outside noise, we first needed to know how much noise was outside. Therefore, a few years back, when the property was mostly abandoned and empty, I performed an acoustical survey of the campus. As expected, the west side of the property was the noisiest, falling off gradually as you moved east. To this survey, we added the shadowing effects that the future buildings would have. The result was something akin to a topographical map, marked in noise instead of height levels. This map was used as a guide to determine the types of construction that would be needed for each section of each building throughout the campus.

Housed within the Worship and Arts Building are the 400 Seat Sanctuary, a large Fellowship Hall used for larger meetings and after school meal programs, classroom space, a modern production kitchen for meal preparation, a movie theatre/lecture hall, a dance studio and piano lab. The theater/lecture hall was designed to serve as a teleconferencing hub in the future.

With a direct line of site to the highway, noise isolation of the movie theater was accomplished with wall and ceiling constructions which included lots of dead air space between the theater and the outside. Similar to the construction of a Thermos bottle, dead air is cheap and only slightly less effective at stopping noise. Typically, fiberglass batt would be placed in the dead air space to absorb cavity resonances. This wasn’t possible in the externally insulated walls of the theater for fear of moving the dew point inside the vapor barrier, so here we resorted to an old trick loudspeaker manufacturers used in constructing 1950s era reflex speaker cabinets; dividing the dead air space with a felt partition.

Instead of felt, we used Freudenberg’s acoustic non-woven fabric called SoundTex. This configuration provides the acoustic impedance needed to absorb cavity resonances but does not cause condensation problems in the wall. The cap of the Thermos bottle construction is an exit door, sound rated at STC50 to stop I-75 traffic noise, originating just 100 feet away.

Generous use of dead air was used to insulate the sanctuary from outside noise as well. The most unique noise isolation wall here has to be the three story glass curtain. Not just your run-of-the mill curtain wall, this one was built with an air gap of 12 inches between the inside and outside glass.

For the parapet walls whose construction created a relatively small dead air space, Serious Materials’ QuietRock 545 laminated panels were specified instead of gyp board to make up the difference.

DEAD AIR

Typically, the easiest method of obtaining dead air space in the ceiling construction is to hang a contiguous gypsum board ceiling several feet under the roof deck, as was done in the theater. But because of the numerous mechanical and audio/video components that are suspended from the roof deck of the sanctuary, there was no room for a gyp ceiling here. The solution was to build the dead air space on top of the roof deck, in a construction similar to that of a joisted floor.

The result: a quiet sanctuary.

Unless visitors knew what to look for, they might have missed the acoustic treatments within the sanctuary. The left wall is wood veneer (constructed from one tree); the right wall is glass windows separated by brick columns; the back wall is glass with a light balcony extending into the space. Although they might have missed it, acoustic treatment is designed into each of these surfaces as perforated wood reveals and wood panels with SoundTex glued to the back of the panels.

The perforated reveals and panels for the Kroc Center were custom made by the local craftsmen at Cassady Woodworks. The hole pattern we settled on is about twice that of ordinary pegboard. I’ve used this technique before (see “The Auditorium on the Top of the World,” W&C, August 2006), and I really like the ability to custom tune the sound absorption to fit the room’s acoustic goals while blending into the architectural design.

Low frequencies in the room are absorbed by the deeply curved, perforated wood and SoundTex nose of the lighting balcony.

At the end of the day, The New York Staff Band gave a concert in the new Sanctuary. Scott Morgan of Copp Systems Integrator, who designed and installed the audio/video systems, was on hand and commented, “No PA was needed and I have to say that the acoustics in the sanctuary were fantastic. Pure ear candy.” Additional comments from well-known performers attest to the superior acoustics of the space.