Bookshelf speaker series monitor audio apex power rating 100 watt principle passive frequency response 60 35000 hz sensitivity 87 dbmw impedance 8 ohm crossover frequency 3000 hz power supply passive housing surface veneer speaker enclosure bass reflex number of tweeters 1 treble chassis 25 mm number of midbass drivers 1 bassmidtone chassis 140 mm width 140 mm height 250 mm depth 140 mm weight 395 kg area of use home cinema hifi s