EPSRC Grant
As the pioneer of the sound diffusion industry, we are happy to see it flourishing and also happy to be making progress in establishing industry standards. We have worked for 16 years on this topic and we are encouraged by the number of people joining the SC-04-02 Working Group. A few years ago RPG co-funded a European Physical Sciences Research Council Grant with Dr. Trevor Cox, Y. Lam and Tristan Hargreaves. We have some good news! The EPSRC grant received an Alpha 4 rating, which is one off the top mark. This means that the research was rated as "A very significant contribution to the field". Learn more at The University of Salford's School of Acoustics and Electronic Engineering Web site.

International Symposium on Surface Diffusion in Room Acoustics
Liverpool, Sunday, April 16, 2000
The main theme of the International Symposium on Surface Diffusion in Room Acoustics will center around the standardization efforts of the AES SC-04-02 and the ISO working groups to define a diffusion and scattering coefficient. The preliminary programme will start with two presentations, one from the ISO WG chairman Jens Holger Rindel and one from the AES Sub-committee chairman Peter D'Antonio, describing the findings of the working groups. The technical details of the definitions and measurement of the scattering coefficient and diffusion coefficient will then be described in presentations by Eckard Mommertz and by Trevor Cox. The programme will also include a number of presentations on the application of diffusers in room acoustics and the modelling of surface diffusion in computer models. A discussion session is scheduled at the end of the presentations to allow delegates to participate in the discussion and give feedback. For more information and a registration form, download the 217K PDF file.

Concert Hall Acoustics: Art and Science
The Royal Festival Hall, South Bank Centre, London, UK
January 28 - February 29, 2000


The free multimedia exhibition is intended to show how science and engineering have influenced the design of concert halls. The science of room acoustics has built up over the last hundred years. Before this, good concert halls were built by a process of trial and error. The features of the best halls were copied, sometimes successfully, sometimes not. It is often assumed that in the past we had some great talent to build good concert halls, and now we have forgotten the know-how, but this is the stuff of myth and legend. Today, with the knowledge and understanding gained through acoustics research, we can build concert halls knowing that the chance of building a good, or even a great hall, is much better. RPG is proud to have taken part in this educational and informative exhibit. Visit online at www.hallacoustics.co.uk.

Diffuse Seminars
RPG is now offering regular educational seminars for acousticians, sound contractors, home theater system integrators, architects, and other specifying consultants to apprise the industry of our research, new products, application assistance, and an introduction to RPG's new Room Optimizer™, Shape Optimizer, and CATT Acoustics software. The press is also welcome.

The response to these educational seminars has been very enthusiastic and current seminar dates are available. If you are interested in attending, please e-mail to info@rpginc.com, contact your local rep or call Jeff Angel at 301-249-0044.

CATT presented the DLL Directivity Interface (DDI) at the Paris AES
In a workshop on array modeling CATT presented the DDI that among many other functions can perform array modeling. Verification examples were shown for the Duran Audio DSP-controlled Intellivox series where azimuth, focus distance and beam width can be selected and a run-time array simulation is performed with sub-degree resolution. In addition, the DDI handles the very long nearfields of large arrays (up to 100 m in many cases) and it was demonstrated that other software, e.g. EASE 3.0, for such cases will make errors in the range of 10-30 dB due to a far-field-only simulation. A DDI white paper is available from the CATT Web site and the workshop viewgraphs will also be made available for download.

The directivity format (SD2) offers array modeling (very high resolution distance dependent directivity) and a very general handling of directivity. SD2 offers a much higher degree of accuracy than the 10-degree "industry standard". The DDI interface is prepared for the new proposed high-resolution AES standard, but lets a manufacturer offer high-resolution data even before a new file-format is agreed on. It also offers data hiding and hiding of intellectual property for DSP-controlled arrays or other special designs. For further details download the white paper in PDF format.

SIAP in North America
Visit the RPG Acoustics Library for a new PDF paper by SIAP on Design Criteria for Acoustic Enhancement Systems, by Ben Kok and Wim Prinssen of Systems for Improved Acoustic Performance, Uden, The Netherlands presented last summer at the 6th ICSV in Denmark.

Abstract
Acoustic Enhancement Systems have evolved significantly — both technically and by acceptance — over the past decade. Numerous publications are available covering the design philosophy and successful installations. For people not directly involved in the implementation of these systems, it often is difficult to determine if a proposed design will perform to expectation in their situation. They are often confronted with large numbers of loudspeakers and microphones at — generally — undesirable places, but have no way of judging if the proposed configuration is the optimum, or that modifications are possible without negative influence to the end result. This paper will describe basic design criteria for Acoustic Enhancement Systems like loudspeaker density, microphone positions, number of required processor in- and outputs, etc. These criteria can act as a tool to evaluate proposed designs, as well as a way to estimate the required provisions to be included in planning such an installation. By presenting these criteria we hope to give our contribution to demystifying the "magic art" of designing Acoustic Enhancement Systems and thereby further increasing their acceptance as a viable tool in modern acoustic design practice.

RPG Factory Summer Shutdown
This year RPG will close its production facility during the week of August 14-20th. We announce this early so that all of our specifiers, clients and representatives can plan their orders and deliveries accordingly.