Consumer Electronics

TIE-CLIP MICROPHONES

There is another type of microphone with a similar purpose, but even more convenient, now gaining popularity. This is the tie-clip or lapel unit shown in Fig 2.22. This is a tiny microphone supported by a small mount which can be clipped on to a tie, lapel, or other convenient part of clothing. One of the prime requirements for such an instrument is small size and lightness. This rather cuts out the moving-coil transducer as there is a practical limit to the minimum size of cone/coil assemblies, also the need for a powerful magnet makes it too heavy for this application.

Here again electret system comes to its own. These units can be made very small and are inherently light. Although they need an internal amplifier, these ...