Ceiling speaker bookshelf speaker on wall speaker power rating 10 watt system 2 way system speaker system 20 stereo principle passive frequency response 100 20000 hz sensitivity 87 dbmw impedance 8 ohm colour black front colour black design front firing subwoofer speaker enclosures wall mounting possible bass reflex number of tweeters 1 treble chassis 50 mm number of subwoofers 1 bass chassis 105 mm speaker terminals clamp contacts width