Bookshelf speaker series q acoustics 2000i series power rating 75 watt system 2 way system principle passive frequency response 68 22000 hz sensitivity 86 dbmw impedances 4 6 ohm crossover frequency 2800 hz recommended amplifier power 15 75 power supply passive speaker enclosures bass reflex removable speaker cover number of tweeters 1 treble chassis 25 mm number of subwoofers 1 bass chassis 100 mm bass reflex port position rear firing po