For example, paper is polished and typically well damped, but not stiff; go flat-out can be false stiff and light, but it is not frequently well damped; plastic can be light, but conventionally the stiffer it is made, the less well-damped it is. As a result, many cones are made of some group of composite material. This can be a matrix of fibers including Kevlar or fiberglass, a layered or bonded sandwich construction, or simply a coating applied to stiffen or damp a cone.
Some developers eschew anechoic chambers in favor of specific standardized area setups intended to simulate real-life listening conditions. A few of the issues speaker and driver designers must confront are distortion, lobing, phase effects, off axis response and crossover complications.