The stand-alone Riedel Bolero wireless intercom system has two operational modes for their four-wire ports;
"4-wire" which assigns the ports input and output to a partyline with a mix-minus between the two.
"4-wire split" allows different assignments of the input and output of the four-wire port.
The Split mode should NOT be used when interfaced to a partyline in a Clear-Com system such as LQ, HelixNet, Freespeak or Eclipse Matrix as it will generate an echo to the talker on the Clear-Com system.