Yamaha NS-B210, 2.0 channels, Wired, 40 W, 75 - 35000 Hz, 6 Ω, Brown Yamaha NS-B210. Recommended usage: Universal. Audio output channels: 2.0 channels. Connectivity technology: Wired. RMS rated power: 40 W, Frequency range: 75 - 35000 Hz, Impedance: 6 Ω, Sensitivity: 86 dB. Product colour: Brown http://www.toptenreviews.com/electronics/home-entertainment/best-bookshelf-speakers/yamaha-speakers-review/ The Yamaha NS-B210 bookshelf speaker is heir to a rich heritage of great audio speakers. From an array of terrific floor standing speakers through the small but mighty Yamaha NS-10 and NS-10Ms that have been ubiquitous in recording studios for many yea... Small enough to place just about anywhere, they’re available in four finish colors, Overall sound quality of the speakers is rather small, reflecting their physical dimensions. Other speakers featured on this site offer better sound and value....