250W Active Subwoofer with Twisted Flare Port in Black A design combining superior operability & beauty. & introducing a new technology, Twisted Flare Port, for clear & tight bass. A subwoofer that will match a wide range of speakers & interiors. New Twisted Flare Port Produces Clear & Tight Bass The all-new Twisted Flare Port takes advantage of extensive subwoofer development experience. The flared, gently twisting shape diffuses the vortex of air generated around the edge of the port, creating a smooth flow of air. This reduces extraneous noise... * PWM digital drive high efficiency amplifier & dual feedback circuit * New Twisted Flare Port contributes to clear & tight bass * Advanced YST II (Yamaha Active Servo Technology II) * 25 cm (10”) cone woofer with square wire voice coil * Beautiful design will match a wide range of speakers & interiors * Front control panel for easy control * System control & Auto standby