Bookshelf speaker series q acoustics 3000 series system 2 way system principle passive frequency response 64 22000 hz sensitivity 88 dbmw impedance 6 ohm crossover frequency 2900 hz recommended amplifier power 25 75 power supply passive colour black front colour black housing surface paint speaker enclosures bass reflex removable speaker cover number of tweeters 1 treble chassis 25 mm tweeter type tweeter calotte number of midbass driver