This sub is massive in every sense of the word. The 21” driver, weighing in at 67 pounds, has a 6” voice coil and is among the lowest power compression in the industry. It moves air below 50 Hz like a folded horn would, with ease. It was designed with emphasis on live sound from 32 to 80 Hz. The woofer is designed like an overgrown 15”, with punchy and clear bass frequency reproduction.