Centre speaker series dali zensor system 2 way system principle passive frequency response 47 26500 hz sensitivity 89 dbmw noise level 109 db impedance 6 ohm crossover frequency 2400 hz recommended amplifier power 30 120 power supply passive colour black cabinet surface ash housing surface veneer vinyl housing material mdf enclosure speaker enclosures bass reflex magnetically shielded removable speaker cover number of tweeters 1 trebl