Aurora Municipal Center, Aurora, Colorado

Aurora Municipal Center, Aurora, CO - Square feet: 265,000 - Cost: $67 million - Completion date: December 2002 Barber Architecture, Denver, Colorado presented the City of Aurora with seven possible schemes for the master plan and design of their future Municipal Center. The City chose a master plan that offers plentiful green space for public gatherings. The Center itself sits at the head of a long park that includes a library, Justice Center and the future Performing Arts Center. The design is a gift to the people of Aurora. Project Architect Deborah Barber of Barber Architecture indicated that the acoustical finishes specified by acoustician Ed Logsdon of D. L. Adams Associates, Denver, Colorado, provided an aesthetic and acoustical solution to both the Lobby and the Council Chambers of the facility. Logsdon was concerned with the circular shape of the room and specified Topakustik®, for wall areas and column covers, and BASWA®phon for the curved ceiling fascia, to control focusing and reverberation time. Logsdon also specified FlutterFree® for the front wall of the chamber to diffuse sound for improved speech coverage, uniformity and intelligibility. The Weitz Company, general contractor on the project, provided a professional installation, which fully realizes the architectural plan and showcases the RPG products in their best light. This view of the chamber shows the FlutterFree® front wall, behind the podium, Topakustik® walls and BASWA®phon on the curved ceiling fascia The front view of the chamber is appointed with FlutterFree® to provide uniform diffusion and good speech intelligibility. The rear view of the chamber highlights the BASWA®phon on curved ceiling fascia and Topakustik® on rear surfaces and column covers. The beautiful lobby utilizes Topakustik® on the column covers to provide a handsome wooden appearance as well as controlling the reverberation time in the large space.

General Mills adds BASWA®phon to the recipe
BASWA®phon was used in the main 2 ½ story center hub atrium center in the new expansion of the General Mills corporate headquarters in Minneapolis, MN. HGA Architects of Minneapolis was looking for a neutral canvas to feature the beautiful hanging colorful art glass display, while also satisfying the acoustical requirements of the large atrium. Acoustician Steven Kvernstoen of Kvernstoen, Kehl & Assoc. in Minneapolis, specified BASWAphon as an aesthetic and acoustical solution to the problem. The final installation was enthusiastically received by HGA Architects and the General Mills corporate management is equally impresses. Enough so to now consider use of BASWA®phon in the renovation of the existing older campus at General Mills.

New Article Reviewing Evolution and Impact of Diffusion Technology
Engineering Art: the science of concert hall acoustics

RPG Variscreens Used in Spatialization Studies at NRL
The figure shows a 28-speaker array surrounded by free-standing Variscreens used by James A. Ballas, Derek Brock, and Justin Nevitt at the Naval Research Laboratory, Washington, DC. Using vector base amplitude panning (VBAP), a technique developed by Ville Pulkki at Helsinki University of Technology, which extends stereo panning to panning with speaker triplets, this array can generate the perception of virtual moving sounds very close to a subject’s head. Using this configuration they are currently investigating whether the auditory display design described and typically rendered through headphones, will work in a noisy ship environment rendered through the loudspeakers. This study appropriately combines both headphone and speaker spatialization techniques.

RPG Invited to Lecture at ASA in Austin, TX
Dr. D’Antonio will present two papers at the upcoming ASA meeting in Austin entitled “Low Frequency Evaluation and Treatment of Small Rooms” and “A New Seamless, smooth, interior, absorptive finishing system” in the Small Room – Big Challenges and Acoustical Design of Government Buildings sessions, respectively. SIAP will also present a paper entitled “Acoustic Enhancement Systems: Design criteria and evaluation of acoustical parameters based on in situ measurements” in the Electro-acoustic enhancement systems in rooms for music.

The Abstracts for Dr. D’Antonio’s invited papers follow. For further information on other topics, please visit our library at www.rpginc.com\news\library.htm or contact RPG.

Low frequency evaluation and treatment of small rooms
Peter D’Antonio (RPG Diffusor Systems, Inc., 651-C Commerce Drive, Upper Marlboro, MD 20774, pdantonio@rpginc.com)

At low frequencies, the acoustical coupling of the listener and loudspeakers with reflections from the room’s boundary surfaces and its modal pressure distribution can cause significant acoustical distortion. For rectangular rooms, software programs exist to predict the magnitude of these effects. However, there is no substitute for experimental measurements. When evaluating small rooms, it is often desirable to isolate the modal effects from the speaker-boundary effects, so that appropriate corrective measures can be applied. An MLS measurement procedure will be presented. After the room dimensions and listener/loudspeaker positions are optimized, one can apply dedicated low frequency absorbers to further control low frequency problems. Characterization of low frequency absorbers will be described, using a 7-ton, 22’ long impedance tube.

A new seamless, smooth, interior, absorptive finishing system. Peter D’Antonio (RPG Diffusor Systems, Inc., 651-C Commerce Drive, Upper Marlboro, MD 20772, pdantonio@rpginc.com)

Government architecture typically employs classic forms of vaults, domes and other focusing or reflective shapes, usually created with hard materials like concrete and plaster. Use of conventional porous absorption is typically rejected as an acoustical surface material for aesthetic reasons. Hence, many of these new and existing facilities have compromised speech intelligibility and music quality. Acousticians have sought a field-applied, absorptive finishing system that resembles a smooth plaster or painted drywall surface, since the dawn of architectural acoustics. Some success has been achieved using sprayed cellulose or cementitious materials, but surface smoothness has been a challenge. A new approach utilizing a thin microporous layer of mineral particles applied over a mineral wool panel will be described. This material can be applied to almost any shape surface, internally pigmented to match almost any color and renovated. Because of these unique characteristics the new seamless, absorptive, finishing system is being specified for many new and renovated spaces. Application examples will be presented.

Acoustic Enhancement Systems: Design criteria and evaluation of room acoustical parameters based on in situ measurements – Bjorn van Munster M.Sc. , Wim Prinssen M.Sc. (Systems for Improved Acoustic Performance B.V., Uden, the Netherlands)

Acoustic enhancement systems have evolved significantly during the years. Where the early systems only aimed to increase the reverberation time in a hall, nowadays the increase of the reverberation time is only one of the features of such a system.
Contrary and additionally to passive acoustics, an acoustic enhancement system enables a designer or acoustical consultant to change the acoustical characteristics of a hall in a more flexible way. Due to the sophisticated convolution processes and layout of such a system besides the reverberation time also e.g. speech intelligibility and spaciousness can be improved or special effects can be added to shows. In this paper the applications of an enhancement system in general will be outlined in more detail. Furthermore design criteria will be given which can be formulated for installation of such a system. These criteria can be used to evaluate proposed designs, but also to estimate the required provisions to be included in the planning of a system installation. Besides, the paper describes the results of in situ measurements of one such system (SIAP) whereby the increase of the reverberation time is evaluated with respect to certain important room acoustical parameters, i.e. reverberant level, lateral efficiency and clarity.

RPG seminars accredited by AIA Continuing Education System
RPG now offers four AIA/CES accredited seminars on various aspects of architectural acoustics.

The Next Generation of Acoustic Finishes, Shapes and Services
   ( AIA/CES AF1011 1 LuHour )
Participants learn how recent innovation and technology has resulted in a much broader variety of architectural finishes, shapes and services that solve age-old acoustic problems in the built environment.

Acoustical Diffusor Design/Computerized Shape Optimization
   ( AIA/CES DD1011 1 LuHour )
Participants learn the basic theory and history of sound diffusion as well as why sound diffusion is so essential in critical listening environments. A variety of methods, materials and products for diffusing sound will be presented.

Minimizing Acoustical Distortion in Critical Listening Spaces
   ( AIA/CES AD1011 1 LuHour )
Participants learn how sound reproduced in a critical listening room can be affected, positively or negatively, by a room's architectural surfaces prior to it arriving at the ears of a listener. A variety of methods, materials and products for minimizing the negative distortion of the reproduced sound are presented.


Desktop Acoustic Auralization of Architectural Spaces
   ( AIA/CES CA1011 1 LuHour )
Participants learn how recent innovation and technology in computer modeling has resulted in a reliable method for predicting the quality of a room's acoustics prior to its construction. Basic theory and examples of its application in practice are presented.

	New Additions Watch this section for new additions to the website.

Recent Completed Projects Q3-2003
Included is a partial list of architectural, home theater and project studio completed projects.