Bookshelf speaker satellite speaker series jbl arena system 2 way system principle passive frequency response 100 40000 hz sensitivity 86 dbmw impedance 8 ohm crossover frequency 2500 hz recommended amplifier power 20 100 power supply passive colour black front colour black speaker enclosures magnetically shielded wall mounting possible number of tweeters 1 treble chassis 25 mm tweeter material tweeter tissue number of subwoofers 1 bass