Floor speaker series heco victa prime power rating 145 watt effective output 265 watt system 25 way system principle passive frequency response 28 40000 hz sensitivity 91 dbmw impedances 4 6 8 ohm crossover frequencies 380 3250 hz recommended amplifier power 30 265 power supply passive housing surface veneer housing material mdf enclosure speaker enclosure bass reflex number of tweeters 1 treble chassis 25 mm number of midbass drivers