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 Beyond Stereo Applications: The A Series features a variety of input options, mounting possibilities, and sound adjustability, making it suitable for multichannel and surround applications Stay in the Zone with Remote Operation: Much of the embedded technologies found in the A Series can be controlled remotely and in real time via the A Control software application for focusing on your project and monitor