Bookshelf speaker power rating 75 watt system 2 way system principle passive frequency response 64 22000 hz sensitivity 86 dbmw impedance 6 ohm crossover frequency 2900 hz recommended amplifier power 25 75 power supply passive colour black housing surface paint speaker enclosure bass reflex number of tweeters 1 treble chassis 25 mm number of midbass drivers 1 bassmidtone chassis 125 mm width 265 mm height 282 mm depth 170 mm wei