Bookshelf speaker series heco victa prime power rating 65 watt effective output 110 watt system 2 way system frequency response 35 40000 hz sensitivity 89 dbmw impedances 4 6 8 ohm crossover frequency 3300 hz recommended amplifier power 20 110 housing material mdf enclosure speaker enclosure bass reflex number of tweeters 1 treble chassis 25 mm number of midbass drivers 1 bassmidtone chassis 120 mm speaker terminals screw terminal gold