Advanced YST
Advanced Yamaha Active Servo Technology (Advanced YST) is a unique system in which the speaker and amplifier work together to cancel out impedance so the speaker unit has a perfectly linear motion. Advanced YST helps to ensure the highest levels of sound pressure and overall performance.
MAIN FEATURES

* Advanced YST II (Yamaha Active Servo Technology II)
* PWM Digital Drive Amplifier
* Front-firing active design
* Linear Port for minimizing extraneous noise
* High 270W dynamic power
* 25cm (10") long-stroke cone driver with magnetic shielding
* 20–160Hz frequency response

Other Notable Features

* 20–160Hz frequency response
* Auto standby with sensitivity selector (High, Low and Off)
* Phase control (Normal or Reverse)

The Subwoofer: a Vital Part of Your System
DVDs and digital music sources hold a huge amount of audio data, including a considerable amount in the low frequency range. Multi-channel sound formats dedicate an entire channel to the low frequencies (the ".1" in 5.1-channel sound), used to deliver the bass in music and explosions, thunder and other low frequency sound effects in movies. Ordinary speakers are not large and robust enough to handle these frequencies, especially for long periods. This is where the subwoofer comes in. By outputting bass sounds with high power and low distortion, it ensures that you are not missing anything, and it also makes the overall sound richer and properly balanced. A subwoofer is thus a vital part of any home theater or even music-focused system.