Floor speaker series dali zensor system 2 way system principle passive frequency response 40 26500 hz sensitivity 90 dbmw noise level 110 db impedance 6 ohm crossover frequency 2400 hz recommended amplifier power 40 150 power supply passive colour black cabinet surface ash housing surface veneer vinyl housing material mdf enclosure speaker enclosures bass reflex removable speaker cover number of tweeters 1 treble chassis 25 mm tweet