Rotatable HPS Waveguide & X-ART Tweeter ADAM Audio HPS (high-frequency propagation system) waveguide technology enables tweeters to disperse sound with controlled consistency, broad in the horizontal axis but tightly focused in the vertical plane. The A Series introduces a rotatable HPS waveguide design. You can shift A Series tweeters in 90-degree steps to continue to benefit from HPS waveguide technology whether you position the speakers horizontally or vertically.  The A Series HPS Waveguide is made from a new glass fiber polymer compound that helps create a clear sound, free of unwanted resonance. The ADAM Audio X-ART tweeter is at the heart of the rotatable HPS waveguide. Handmade in Germany, the X-ART tweeter provides a precise transient response and reproduces the finest sonic details. This X-ART tweeter is used in every A Series speaker, providing a detailed, consistent sound across the product line. Multi-Layer Mineral Woofer A Series woofers are constructed with a unique blend of mineral stone fibers that have been baked together to create a lightweight but highly stable material. The mineral composition, layering and geometry of each cone is specific to the driver used in each model. By combining this material with a new magnet system, A Series woofers produce high output with low distortion, delivering a clean low-end. Midrange Driver Adapted from the groundbreaking ADAM Audio DCH™ midrange driver used by the S Series speakers, the A Series midrange driver