Acoustical Properties of KYDEX® Thermoplastic Sheet
INTRODUCTION
RPG has incorporated KYDEX® sheet, which carries a Class 1/A fire rating into the Formedffusor to create an exceptional acoustical product.
The following are performance specifications for the RPG Formedffusor product, which was designed and tested by RPG:
ABSORPTION COEFFICIENT
The Formedffusor is designed to offer wide angle, broad bandwidth sound diffusion as well as useful low frequency absorption. These features control excessive boominess and balance the room’s reverberation response. The Formedffusor can be used to offset the usually predominate high frequency absorption of people, drapery, rugs and porous materials.
Absorption Coefficients and Noise Reduction Coefficient for the product were measured by an independent, accredited NVLAP facility according to the test methods as defined by ASTM C 423 and ASTM E 795. Random incidence Absorption Coefficients for the product in an E-400 mounting shall be as follows:
| 125Hz | 250Hz | 500Hz | 1000Hz | 2000Hz | 4000Hz | NRC |
| 0.53 | 0.37 | 0.38 | 0.32 | 0.15 | 0.18 | 0.30 |
DIFFUSION
The Formedffusor is based on the QRD reflection phase grating introduced by RPG in 1983. It offers broad bandwidth wide angle diffusion. The graph illustrates the average diffusion coefficient (1 is ideal) for all angles of incidence. Compared to a flat reflecting panel, the QRD maintains uniform diffusivity as a function of frequency above the diffraction limit.
ADHESIVE AND ASSEMBLY
Diffusion Coefficients for the product were measured in accordance with the recommendations of the Audio Engineering Society Working Group SC-04-02 boundary measurement technique. The directional diffusion coefficient is given by the standard deviation of the 1/3-octave polar response, for a given angle of incidence, and normalized by the response of a flat panel of similar size.
The average incidence diffusion coefficients determined at 5° intervals between ± 85° are listed below at octave-band centers. The mean and standard deviation (SD) of the 1/3-octave-band coefficients are also tabulated.
| 125Hz | 250Hz | 500Hz | 1000Hz | 2000Hz | 4000Hz | Mean | SD |
| 0.71 | 0.73 | 0.88 | 0.8 | 0.69 | 0.56 | 0.72 | 0.1 |
*NOTE: All design concepts and testing was completed by RPG. These results are specific to the Formedffusor product and should not be used for specification work. All testing is the responsibility of the end user.
For further information on Formedffusor contact RPG at:
651-C Commerce Drive Upper Marlboro, MD 20774 Phone: 301-249-3912 Fax: 301-249-0044 Email: info@rpginc.com
Because we cannot anticipate or control the many different conditions under which this information and our products may be used, we do not guarantee the applicability of the accuracy of this information or the suitability of our products in any given situation. Users should conduct their own tests to determine the suitability of each product for their particular purposes. Data in the physical property table represents typical values and are to serve only as a guide for engineering design. Results are obtained from specimens under ideal laboratory conditions. Right to change physical properties as a result of technical progress is reserved. THE PRODUCTS DISCUSSED ARE SOLD WITHOUT WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE, EITHER EXPRESSED OR IMPLIED, EXCEPT AS PROVIDED IN OUR STANDARD TERMS AND CONDITIONS OF SALE. Buyer assumes all responsibility for loss or damage arising from the handling and use of our products, whether done in accordance with directions or not. In no event shall the supplier or the manufacturer be liable for incidental or consequential damages. Also, statements concerning the possible use of our products are not intended as recommendations to use our products in the infringement of any patent. Consult local code and regulatory agencies for specific requirements regarding code compliance, transporting, processing, recycling and disposal of our product. Product not intended for use as a heat resistant surface. Texture, product grade and other conditions may cause variations in appearance.
This information supersedes all previously published data.