Weird hissing/static sound from dynamic microphone

Question

I recently bought a Behringer XM8500 dynamic microphone, plugged it into my audio interface (Focusrite Solo first generation) and noticed that no audio was coming from it (no signal was being produced enough to light the LED light that shows when it is receiving audio).

When I talk into the microphone and record, I can barely hear myself.

However, the interface must not be at fault, since I have a Sennheiser MK 4 condenser microphone, with no problems whatsoever.

Here's a sample: https://voca.ro/1nRqGDepN6uy

Is it the cable? Even though it works with my condenser microphone, is there still a chance my XLR cable isn't working properly with the Behringer? Or might it just be that the microphone is faulty?

Answer 1

It might be faulty. However I have the same microphone which I use with a Behringer UM2 interface. The mic is considerably less sensitive than an electret/condenser mic (which has a built-in pre-amp) so I need to turn the input sensitivity up to maximum on the UM2, after which the signal is fine. If you have the XLR version of your Sennheiser mic then the cable that works with that should be fine with your XM8500.

Answer 2

Dynamic microphones are low-impedance low-level microphones. Due to the low impedance, they have a rather small base noise level but need to be well-encapsuled to keep that so. They also need a large-gain preamp. In contrast, the first preamp stage of a condenser microphone is always built-in since a condenser capsule needs the first preamp stage to be very close in order to produce sensible results. This first preamp stage is then powered either by battery or phantom power. In contrast, a dynamic microphone gets along without such a preamp stage and thus without external power.

This is no longer universally true: there are several ribbon microphones (a special type of dynamic microphone) by now with built-in preamps that consequently need phantom power. Unfortunately there are also such ribbon microphones that phantom power may damage them.

So a dynamic microphone tends to need a good low-impedance high-gain preamp. Focusrite should be ok if you dial up gain all the way.