Centre speaker series tannoy mercury power rating 60 watt effective output 240 watt speaker system 20 stereo principle passive frequency response 62 32000 hz sensitivity 91 dbmw impedance 8 ohm crossover frequency 3500 hz capacity 62 litres power supply passive colour black front colour black cabinet surface oak design front firing subwoofer speaker enclosures removable speaker cover bass reflex number of tweeters 1 treble chassis 28