Amazon.ca Product Description The black NS-SW100 from Yamaha is a powered 10" subwoofer designed to provide rich and impactful bass response making it well suited for home theaters game setups and music reproduction. The NS-SW100 utilizes a twisted flare port which reduces air turbulence noise when compared to a conventional port resulting in clear and accurate low frequency reproduction. The inclusion of Advanced Yamaha Active Servo Technology II (Advanced YST) allows the speaker and amplifier to work together to cancel out impedance so the speaker unit maintains linear motion and ensures the highest levels of sound pressure and overall performance. The rear panel offers a single RCA input power switch and volume control. From the Manufacturer This compact subwoofer incorporates a number of Yamahas advanced high-performance bass technologies such as twisted flare port advanced YST ii (Yamaha active servo technology ii) with discrete amp circuitry and a high-quality 10" woofer unit. The resulting bass response is powerfully rich and impactful.