Yamaha NS-SW300 Active Subwoofer

Here we have a nice subwoofer from Japanese company Yamaha. It is in good fully working condition with a couple of minor marks – please see photographs. It will be carefully packaged and comes with a manual plus our normal three month warranty.
Yamaha Say….
A design combining superior operability and beauty. And introducing a new technology, Twisted Flare Port, for clear and tight bass. A subwoofer that will match a wide range of speakers and interiors.
Features:
PWM digital drive high efficiency amplifier and dual feedback circuit
New Twisted Flare Port contributes to clear and tight bass
Advanced YST II (Yamaha Active Servo Technology II)
25 cm (10”) cone woofer with square wire voice coil
Beautiful design will match a wide range of speakers and interiors
Front control panel for easy control
System control and Auto standby
The all-new Twisted Flare Port takes advantage of extensive subwoofer development experience. The flared, gently twisting shape diffuses the vortex of air generated around the edge of the port, creating a smooth flow of air. This reduces extraneous noise not present in the original input signal and provides clear, accurate low frequency reproduction. From special effect sounds in movies to the atmosphere of a live venue, you hear bass that is clear, tight and realistic.
The built-in power amplifier delivers stable power output of 250 W with high efficiency while minimizing power consumption and heat production. It does not require an output filter coil, resulting in extremely low noise and distortion. High speed transient response is also excellent. The dual feedback circuit reduces distortion by applying feedback twice, resulting in higher sound clarity.
Developed by Yamaha, the Advanced YST II (Yamaha Active Servo Technology II) combines negative-impedance and constant-current principles to drive the speaker cone with even tighter control than the previous version. Using Advanced Negative Impedance Converter (ANIC) circuits, this system dynamically optimizes effective speaker impedance to maintain excellent linearity. This means more stable and accurate low range response, not to mention higher sound quality.
A 25 cm (10”) large woofer unit is used in a front-firing configuration. The voice coil of the driver unit employs square wire with a wide surface area that can be wound more densely to obtain higher magnetic flux density. It delivers high drive force, permitting tight and deep bass reproduction.
In addition to the beautifully round shape of the front surface, panels on both sides to create an accent, and a neat appearance, this subwoofer lets you imagine the strength of sound and matches a wide range of speaker systems. Numerous colour variations are provided, so you can select one matched to your interior.
The power and volume buttons, which are used most often, are laid out on the front surface of the unit for ease of access. It is inclined at an angle of 45°, making it easy to use even when placed on the floor. An LED indicator is above the power button, so even in a dimly lit room it’s easy to tell if it’s on or off.
Specifications:
Driver: 25 cm cone
Output Power: 250 W
Frequency Response: 20 – 160 Hz
Standby Power Consumption: 0.3 W
Dimensions: 366 (H) x 350 (W) x 420 (D) mm
Weight: 18.0 kg