Bookshelf speaker series q acoustics 2000i series system 2 way system principle passive frequency response 64 22000 hz sensitivity 88 dbmw impedances 4 6 ohm crossover frequency 2900 hz recommended amplifier power 25 75 power supply passive colour white speaker enclosure bass reflex number of tweeters 1 treble chassis 25 mm number of subwoofers 1 bass chassis 125 mm bass reflex port position rear firing port width 264 mm height 278 m