Gravis II is a perfect choice for more demanding audio systems. It features a front-firing 10» passive radiator with a down-firing 10» active unit, along with a high current 400W Class AB amp. The combination of a larger cabinet, perfectly tuned to the larger driver compliment, and 400 watts of refined power provides excellent bass extension with the speed, impact, and nuance required to underpin the most engaging music and theater systems.