Electronic – High to low impedance microphone

impedancemicrophone

I'm a helicopter pilot. I'm thinking of buying a headset Bose A20. My problem is that the Bose headset comes with a high impedance microphone, but the helicopter I'm operating is using a low impedance 5 ohm system. The most common systems use high impedance.

My question is…

Is there any chance to build an adaptor to convert the signal of the headset to a low impedance microphone signal?

Best Answer

To answer your question directly, yes. That device, most generally, is called an amplifier.

The effect, in your situation, of just connecting the microphone/radio anyway (without an amplifier) will be that your microphone will appear to be much less sensitive than you expect.

However, you can't hurt anything, so you should just try it. You might be surprised with how well it works (e.g. good enough). There are a few things working in your favor:

  • Good radio transceivers (especially in aerospace) use an auto-gain/leveling function on their mic inputs, which may compensate the lower input level.

  • Professional (expensive) microphones use larger elements and are typically much more sensitive than "standard" elements that the inputs are designed to handle.

  • The output impedance may be specified based on maximum compatibility rather than actual hardware impedance.

...so, yeah, you should just try it first.