DM Electronics
DM Electronics
Aviation Headset Experts
Phone 1300 767 101

Microphone Technique

By simple microphone techniques such as, talking  just a little bit softer into the microphone, and placing the microphone in the correct location, you can often make your radio calls and intercom conversations substantially clearer. Its the difference in a radio check reply of “reading you 4” to “reading you 5”, loud and clear.

Before anything else, if your using a microphone we recommend that you be using a microphone windscreen, also known as a mic muff or wind and pop filter. Its a simple open cell foam piece that slips over your microphone. It also provides protection to your microphone from the elements and any spit or moisture that projects from your mouth while talking, which in some cases can damage the microphone and reduce its life. If you are flying open-cockpit then its mandatory to be using a muff suitable for that environment. We offer microphone windscreen with a leather windshield with added wind protection specifically for open cockpits.

The placement of the microphone is simple but can vary for different types. In general, we recommend placing the microphone just below your mouth or in front of chin and about one inch away from your lips. Also make sure the microphone (talk side) is directed at your mouth. The important thing about placement is that the microphone must not be in the direct line of fire of the air moving from your mouth as you speak. This causes pops and over modulation of the microphone, a distorted and uncomfortable sound that no one wants to hear. It usually occurs when pronoucing the letters “T” or “S”. To check for the perfect location, say the letter “T” continuously while feeling the air coming from your mouth with one of your fingers. The microphone should be placed out of the air movement area as you say this letter “T”. After moving the microphone to this recommended position you may notice that the volume of the sidetone is lower, and if this is the case your first step should be to turn up the intercom volume.

To confirm, as you should before becoming airborne or conducting a mission, conduct a radio check. If the radio check reveals low volume on the receiving end, there are a few things that could be causing this lack in microphone performance.

  • A few microphones have a gain adjustment, and you can try turning this up.
  • Check your microphone impedance. It should suit your radio equipment.
  • Check that other connected users within the radio system aren’t using an incompatible microphones (impedance mismatch) or microphones with substantially different impedance to you own. This is particularly important where microphones are wired in parallel, together.
Similarly, if the radio check results in distortion or over volume, try moving the microphone further from your mouth, talking quieter or if your microphone has a gain adjustment, adjusting the gain level down. Again microphone impedance can also be an issue.
Further to this, some radios have gain adjustments but this should only be adjusted by a suitably qualified person.