This 12 in. 2,500 watt Gothic Series 2Ω Dual Voice-Coil Subwoofer from Power Acoustik use torsion-twisted flax fibers that are woven together for ultimate strength and less elasticity. A heavy soaking in epoxy combined with the sonic qualities of pulp paper, flax proves itself worthy of any system. A strong and flexible heat-resistant compound, nitrile butadiene rubber is used widely in automotive applications. Gothic woofers also utilize an extended excursion NBR surround for its strength and flexible properties during extreme movement.