Sennheiser AC 41 Active Antenna Combiner for Evolution G4 WirelessActive antenna combiner for evolution wireless G4 systems. The AC 41 operates up to four wireless stereo transmitters from the ew series using one shared antenna. Power is supplied to the SR IEM G4 transmitters over the BNC cables via NT 3 1 power supply (included with the AC 41), making separate power supplies for the transmitters obsolete. Features: Up to 4 wireless stereo transmitters using one antenna Power supply via BNC cables ensures efficient