Amazon.com Product Description
The Yamaha YST-SW305 has a slim-line design measuring only 9.25 inches wide, letting you position the subwoofer either vertically or horizontally. Front (rather than rear) panel controls make it easy to see the settings and make adjustments when necessary. The 200-watt amplifier power assures sufficient juice to deliver theater-like bass effects, and the dual 8-inch spruce-cone drivers translate that power into clear bass sound. This subwoofer has a frequency range of 20 Hz to 160 Hz.
The adjustable, continuously variable high-cut filter can be set anywhere from 40 Hz to 140 Hz. For instance, if the filter is set at 75 Hz, only frequencies 75 Hz or below will be delivered. This allows the sub's output to be matched to the other speakers in the system and to the room's acoustics for a seamless presentation. 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 from small speakers.
For convenience, the YST-SW305 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. The sub also has a manual override. A phase normal/reverse switch makes it easy to phase the subwoofer with the other speakers in your system, while two sets of inputs allow the versatile subwoofer to accept either line-level or speaker-level input signals.