ADVANCED ACTIVE SERVO TECHNOLOGY
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. Yamaha's Advanced Active Servo Technology is a complementary amplifier/speaker system utilizing negative impedance feedback in the amp and a Helmholtz resonator in the speaker to provide strong and accurate bass.

10-INCH DRIVER AND 250 WATT PWM AMPLIFIER*
High amplifier power assures enough power to deliver shattering movie theater-like bass effects, and the down firing 10-inch long stroke cone driver translates the power into clear bass sound. The PWM digital drive amplifier is extremely efficient and stable. The YST-SW315 has a frequency range of 20 to 160 Hz.

BASS SELECTOR
Yamaha's BASS (Bass Action Selector Switch) tailors the sub's output for video or music at the touch of a switch.

YAMAHA QD-Bass TECHNOLOGY
A Yamaha technology that uses a down firing driver to radiate the bass output more efficiently. Sound is radiated in all directions for greater impact. QD-Bass (Quatre Dispersion Bass) technology uses down-firing drivers with square, pyramid-shaped reflective plates to radiate the sound efficiently in four horizontal directions. The reflective plates negate any effects caused by the floor surface and reduce resonance between sound waves reflected from the floor and the unit.

MAGNETIC SHIELDING
The subwoofer is magnetically shielded so it can be placed near a TV monitor or receiver without degrading the picture.