Active speaker pa speaker principle active woofer size 8 inch construction bi amping speaker lf 2x 8 dimensions 305 x 370 x 637 mm weight 177 kg power handling peak 800 watt noise level 124 db impedance 4 ohm frequency response 45 20000 hz connections sd card microphone usb types of connection rcacinch stereo clamp contacts usb case material bass reflex