The active subwoofer in the Signature 700 series is far too good to be hidden away, because it too features a high-gloss black or white front panel and a satin cabinet in the same color. Even more interesting is the technology inside, as the 300 mm woofer radiates downwards in a "down-firing" configuration. The long-throw chassis has been optimized by using Klippel laser measurement technology. A highly efficient Class D power amplifier drives the subwoofer with 190 or 380 watts of continuous/music power respectively. The Signature Sub 730 A can reproduce powerful sounds down to 19 Hz, and the volume and crossover frequency can be precisely coordinated to suit the acoustics of the room and the main speakers used