Hot topics in architectural acoustics: New materials

Abstract

While both new metrics for measuring sound and analytical software programs for predicting sound performance have proven to be powerful tools of architectural acoustics, new acoustical materials have allowed us to further engineer these sensitive soundscapes. These developments embrace several areas of contemporary acoustical materials. HVAC liners have seen the addition of fiber-free alternatives to traditional linings. New solutions include coated polyimides and melamine foams. In electroacoustics, materials that have improved performance are now replacing some old standbys. PEN materials such as Kaladex are finding more acceptance for use in tweeter domes and microphone elements. Liquid crystal polymer fibers, such as Vectran, which can be used instead of aramid and carbon fibers, offer similar performance improvement for wet lay-up direct radiator transducer cones. Absorptive panels have moved beyond fabric wraps. They are now paintable and can mimic typically reflective treatments. Finally, diffusers have shown advances in both acoustical performance and geometries that better blend with aesthetic goals. These new surfaces consist of a wide range of surface type including modulated reflection phase gratings, binary amplitude gratings, and most recently boundary-element optimized surfaces of constant or variable impedance. Each of these exciting developments are reviewed in this presentation.