Ceiling speaker in wall speaker series bose virtually invisible power rating 50 watt system 2 way system principle passive impedances 4 6 8 ohm recommended amplifier power 10 100 power supply passive colour white housing surface paint housing material plastic enclosure speaker enclosures closed without casing number of tweeters 2 treble chassis 25 mm number of subwoofers 1 bass chassis 178 mm width 254 mm height 254 mm depth 112 mm we