WATCH Dog The second generation WATCH Dog subwoofer has undergone the most radical redesign of any of the WATCH System components. Specifically, it has been transformed from an active subwoofer (with a built-in amplifier) to a passive, unamplified unit. Two considerations drove the design change: Quality and Flexibility The WATCH Dog Passive Subwoofer, added to your music/theater system, will function, at the flick of a switch, in either two-channel or 5.1/7.1 surround mode, affording wither system up to an extra octave of clean, tactile bass response. Superior low frequency performance—whether as part of a home theater system or in a two-channel music system—demands high quality, high current amplification. The active WATCH Dog certainly provides both. Nevertheless, listening tests clearly show that the most cohesive systems are those with matching amplifiers driving all of the loudspeakers, including the subwoofers. The new passive WATCH Dog provides the most cost-effective and flexible approach to that goal, whether in a single unit or a multiple configuration. Key to this flexibility is the new external WATCH Dog Controller. A true subwoofer, capable of clean, distortion-free sub-frequency response, has to be sufficiently large to move the volume of air which visceral frequencies require. As hard as come manufacturers may try, there's no getting around the laws of physics on the one. The good new is, the passive WATCH Dog is 40 % smaller than its predecessor, while maintaining the same internal tuned volume. So the new WATCH Dog is easier to place in your listening environment with no sacrifice in performance. # Enclosure Type Passive Dog: Front Ported # Woofer: 13 inch, dual spider # Nominal Impedance: 8 ohms # Sensitivity: 89 dB @ 1 watt (2.83 v at one meter) # Overall Dimensions: * Height: 26 7/8" (68.26 cm) with spike * Depth: 25 1/8" (63.82 cm) * Width: 18" (42.72 cm) # System Product Weight: 211 lbs (95.7 kg)