The 3201 bookshelf loudspeakers are very compact and can reproduce an exceptional sound image. Hard to believe that such musical qualities can get out of such small boxes! Titanium dome tweeter Metal/ceramic cone Excellent bass level Flat frequency response Bi-wiring or bi-amp terminals Excellent phase and transient response Type : 2 ways Recommended amplifier : 10 - 50W Sensitivity : 84 db/1 W/1 m Impedance : 6 ohms Frequency response : 65 Hz - 20 kHz Dimensions : H12.6" x W11.2" x D14.1" / H320 x W285 x D360 mm Weight : 13.2 lbs ; 6 kg