... the past complicated Features: 1.RS40 wireless speaker set the transmitter,receiver,amplifier,and speaker as a whole. 2.Plug and ... the functions of audio output, input,high and low volume ,digital echo 7.A group of out-fitted wired microphones input ... antihowling performance Better MobilityWireless speaker system build in one FM transmitter(DC9V) and FM receiver (DC12V) with 12 watts(5 subwoofer) + 2 ...