Road Roaster A remarkable subwoofer full of state-of-the-art technology. The speaker has a Dual voice coil. This feature allows the voice coil to travel at greater distances with very low distortion. A much higher efficiency is achieved, as the inner voice coil is considerably closer to the magnet plate than in most other speakers. The unique design of these 'double driving' hi-tech voice coils and the perfect symmetry result in a very low harmonic distortion. The performance of the speaker is further enhanced by the dual spider suspension in a "push-pull" configuration. Free Case Included!