Compact 50W subwoofer that incorporates a number of advanced, high-performance bass technologies exclusive to Yamaha, including a twisted flare port and advanced YST II (Yamaha Active Servo Technology II). This results in sensationally clear bass response and adds a lot to the overall musical experience. The port has a flared, gently twisting shape that diffuses the vortex of air generated around the edge of the port, creating a smooth flow of air. This reduces extraneous noise not present in the original input signal and provides clear, accurate low frequency reproduction. Developed exclusively by Yamaha, the advanced YST II (Yamaha Active Servo Technology II) combines negative-impedance and constant-current principles to drive the 8” speaker cone with even tighter control than the previous version. Using Advanced Negative Impedance Converter (ANIC) circuits, this system dynamically optimizes effective speaker impedance to maintain excellent linearity. The gently rounded form of the speaker with a slanted front surface presents a stylishly elegant appearance. Designed to be unobtrusive, the subwoofer looks beautiful in a living room or home theatre. Frequency response: 28-200 Hz. Dimensions: 291 x 292 x 341 mm. Weight: 8.5 kg.