Aurum Cantus midwoofers feature high-performance cone materials, long-excursion designs, and high quality construction. The AC-180F1D utilizes a composite cone of carbon fiber and polypropylene and an inverted rubber surround for a smooth frequency response with minimal breakup. The dual voice coil construction allows you to have more wiring options for the crossover or with multiple drivers. High sensitivity and smooth response is great for compact two-way designs.