DESC: Home cinema speakers must combine high-power capabilities with excellent sensitivity and dynamic range, while being designed to prevent listening fatigue. The new 225 Series speakers meet these requirements by using a PMD (Polymer-Injected Mica Diaphragm) cone woofer. This diaphragm is composed of 30 percent high-quality white Indian Pearl Mica, chosen for the significant contribution it makes to sound quality. In order to maximize its distinctive qualities, absolutely no coloring is added to the material. Yamaha has also varied the cone thickness, making it thinner on the outer edge, which has been shown to improve performance. Kapton bobbins help to increase signal-to-noise ratio. The cone is extremely light, yet also tough and durable, with excellent response speed.