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.

High amplifier power assures enough power to deliver shattering movie theater-like bass effects, and the down firing 8-inch cone driver translates the power into clear bass sound. The YST-SW215 has a frequency range of 30 to 200 Hz.

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

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.

The subwoofer is magnetically shielded so it can be placed near a TV monitor or receiver without fear that it will degrade the picture.

The user adjustable continuously variable high-cut filter sets the highest frequency the subwoofer will deliver. It can be set anywhere from 50 to 150 Hz. For instance, if the filter is set at 75 Hz, only frequencies 75 Hz or below will be delivered by the subwoofer. This allows the sub's output to be matched to the other speakers in the system and the room's acoustics for a seamless presentation.

The volume control permits the perfect matching of the sub's output to the overall volume of the system.

For convenience, the YST-SW215 has a signal sensing circuit.When the subwoofer detects an audio signal, it turns its power on. When it senses no signal for several minutes, it shuts itself off.

Makes it easy to phase the subwoofer with the other speakers in your system.

Two sets of inputs allow the versatile subwoofer to accept either line level or speaker level input signals.

Yamaha's three-way speaker terminals accept banana plug and a variety of other connectors, as well as speaker wire.

The YST-SW215's cabinet is constructed of thick MDF to increase rigidity and reduce vibration and resonance.