Using Microphones

The use of microphones is an important part in audio production and recording. Microphones amplify the sound coming from different sources such as human voice and musical instruments. An audio output with excellent quality needs a microphone of quality and high caliber as well. One may also think that using the microphone is just simple and easy. However, there is more to simple plugging in and pointing the microphone to get the desired output.

Microphones are not all the same. This audio equipment has different properties that vary from one microphone to another. These properties should be taken into consideration when choosing or buying a new microphone.

Directionality
There are microphones that are omni-directional which means that they can pick up sounds evenly in all directions. Other microphones are bi-directional, which pick up sound coming from opposite directions, or uni-directional such as a cardioid or hypercardioid. It is important to know the directional pattern of the microphone to be able to position it correctly.


Impedance
Though this may not be a critical factor for a microphone to work, it is best to consider this characteristic     when choosing a microphone for better audio quality. A microphone that has a low impedance rating is     better than those with high impedance. The impedance rating can be seen either on the microphone         itself or on the manual.

Frequency Response
Microphones also differ in its response to different frequencies. A microphone that has a flat response means it is evenly sensitive to all frequencies. Thus, it is the ideal microphone to use. But depending on the purpose, tailored response may also be better to use.

Noise Handling
Noise is common in any electronic device. Generally, noise is the unwanted signal coming from     different sources. If pure, high quality audio is desired, it is best to choose a microphone that has some protection from noise such as suspension or foam padding.

When using the microphone, distance is the most important factor to be considered. Distance dictates the type of audio output the microphone will provide. In most cases, placing the microphone as close as possible to the source of sound is acceptable as long as there is no unwanted noise. A good balance between the sound source and ambient noise is the ideal condition.

A microphone placed too close to the mouth of the speaker may produce a boomy or bassy voice. Distortion happens when a microphone is placed too close to a very loud source. With guitar amplifiers, the microphone is placed very closely to isolate the sound from other noises. Similarly, snare drums need to have the microphone close to the skin to get the desired sound. Different applications and purpose require different positioning of the microphone. Trial and error technique may be needed to get the right distance.

Here are other pointers that need to be considered in using a microphone:

  • It is best to keep the microphone cables secure and steady by taping or clipping them in. Hanging cables can easily be kicked which can cause unwanted noise and vibrations to the output. Avoid bending the microphone cables also as it easily deteriorates the performance of the device.
  • Keep the microphone and cable connectors clean. An oxide film tends to build up on the connectors which results in higher resistance.
  • Microphones should not be used in extremely humid setting or be dropped as this affects the sensitivity of the device.
  • Avoid plugging and unplugging the microphone while it is still turned on. Hot-plugging may damage the device, especially the less robust ones.
  • When using microphones in recording, it is best to be conscious on other possible sources of unwanted sound or noise. Quartz watches, wall clocks, fans, computer drives and other small outside noises can interfere with the recording.
  • If using multiple microphones, ideally, the distance between microphones should at least be five times the distance of the microphone from the source to avoid crosstalk.