FBE200-LAN External Audio Input Impedance Requirement

What is the impedance requirement for a FBE200-LAN when using the LINE/AUX-IN port? The audio is intermittent when I connect a wireless microphone receiver to the port. I had a similar experience with an iPad, where it was not detecting the wireless mic because the iPad needed to see less than 10K Ohms before it would switch to the external mic input. Based on tests that I have done, it appears that the FBE200 needs an even lower impedance. Please recommend the impedance needed for proper function.

My dear friend

1)The impedance of fbe200 line in input should be less than 600 Ω
2)The connector connecting FBE200 LINE IN should be three-segment. Is your wireless microphone right?

have a good day

The wireless mic is an unbalanced TS out, so only 2 segments. I can construct a resistive impedance matching network, so do I need a balanced 600 Ohms across both audio channels or can it be unbalanced for only 1 audio channel?

You need a balanced 600 Ohms across both audio channels