I don't understand what Sennheiser has to do with this thread. The OP has a Shure UHF system. Different manufacturers use different compandoring techniques, as well as different frequencies, even in the same bandsplits. Sennheiser, along with SONY, is also one of the most expensive lines of wireless microphone systems, plus their stuff all has to come from overseas. I've been there and done it all with the wireless guys and found that the smart people stick with Telex and Shure, to name just two of the "good guys" in the business. There are a few others as well.