(Hopefully not off-topic noob question)
We have a hearing loop set up which uses a Sennheiser collar radio mic and receiver which works pretty well. We recently bought a handheld Sennheiser mic for use in meetings so that hearing loop users can hear speech from audience members. Unfortunately, when both mics are switched on, there is a lot of mid-high frequency interference which makes the system barely useable.
Is there any way to salvage this setup? I've tried various different frequencies and all sound pretty much the same. Do we need a receiver that runs on separate frequencies for each mic?