... 2.standard 3-pole connector 3.damping factor>600 digital amplifiers HA 450,HA550,HA650,HA800,HA900,HA1000 feature:HA ... such as concert touring , opera houses, theaters, cinemas, amusement parks, radio and television industrial. HA450HA650HA800HA10008Ω stereo output powe450W*2650W*2900W*21100W ... advice for speaker box will be offered freely. digital amplifiers HA 450,HA550,HA650,HA800,HA900,HA1000