yamaha yst-sw315 10-inch digital pro series subwoofer black
yamaha s yst-sw315 offers 250 high-efficiency watts -- enough power to deliver shattering movie-theater-like bass effects . full enjoyment of dolby digital and dts surround sources requires deep clear bass . this is especially true with 5.1 - and 6.1-channel sound because the .1 channel is dedicated to the bass frequencies . that means you not only need a subwoofer but a high-power subwoofer capable of handling extremely low frequencies . the yst-sw315 s down-firing 10-inch driver translates power into clean bass sound and the yst-sw315 boasts a frequency response of 20 to 160 hz -10 db at the extremes of the range . the yst-sw315 delivers high power at deep bass frequencies with excellent stability and low power consumption . this is made possible by the sub s highly efficient pwm pulse-wave modulation digital-drive power amplifier . the amplifier achieves superior conversion efficiency by minimizing power loss from the power transistors . it delivers stable audio power while minimizing ac power consumption and heat production . as it requires no output filter coil it s extremely quiet with low distortion . yamaha s patented advanced active servo technology advanced yst generates incredible bass from small speaker enclosures . this system uses negative-impedance feedback in the amp and a helmholtz resonator in the speaker to provide strong and accurate bass . qd-bass quatre dispersion bass technology uses a down-firing driver with square pyramid-shaped reflective plates to radiate sound efficiently in four horizontal directions . the reflective plates not used in other brands down-firing subwoofers negate any effects caused by the floor surface and reduce resonance between sound waves reflected from the floor and the unit . most other systems use circular cones but the yst-sw315 avoids firing sound into the legs of the cabinet by radiating in four directions . changing the height of the pyramid varies the acoustic load permitting relatively simple high-cut adjustment and improving bandpass properties . qd-bass also grants greater freedom of placement since the sound radiates with equal effectiveness in all directions . the user-adjustable continuously variable high-cut filter sets the highest frequency the subwoofer will deliver . it can be set anywhere from 40 to 140 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 lowest reproducible frequency of other speakers in the system and the room s acoustics for a seamless presentation . the rotary volume control permits the perfect matching of the sub s output to the overall volume of the system . the yst-sw315 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 . yamaha s bass bass action selector switch tailors the sub s output for video or music at the touch of a switch . two sets of inputs let the sub accept either line - or speaker-level inputs while a handy phase normal reverse switch makes it easy to phase the subwoofer with the other speakers in your system . three-way speaker terminals accept banana plug and a variety of other connectors as well as speaker wire and the yst-sw315 s thick rigid mdf cabinet reduces vibrations and resonance . the speaker s handsome black-ash finish blends in with room decor and complements many furnishing styles and it s magnetically shielded so you can place it near a tv or computer monitor without degrading the picture . what s in the box subwoofer user s manual and warranty information .