Microphones are responsible for converting sound into electrical signals, allowing voices, instruments, or acoustic environments to be amplified, recorded, or transmitted. There are different types depending on their technology, pickup pattern, or application: dynamic, condenser, electret, omnidirectional, cardioid… Each has its own advantages and adapts to different environments and needs.
The audio chain begins at the sound source, and if that source is a microphone, how well it captures the audio will largely determine the final sound quality delivered by the loudspeakers.
What does it mean for a microphone to be cardioid?
It mainly captures sound from the front, with lower sensitivity on the sides and rejection at the rear.
It helps isolate the main voice and reduce ambient noise or feedback.
What does it mean for a microphone to be omnidirectional?
It captures sound equally from all directions (360° around).
Ideal for recording ambient sound, groups, or situations where the speaker moves.
What is the difference between balanced and unbalanced signals?
A balanced (or symmetrical) signal uses two conductors for the signal and one for ground, which reduces interference and allows for long cable runs.
An unbalanced (or asymmetrical) signal has a single conductor for the signal and another for ground; it is more susceptible to noise and is recommended only for short distances.
XLR or stereo jack connections indicate a balanced signal; mono jacks are typically unbalanced.
NOTE: Sometimes it is necessary to connect a balanced signal to an unbalanced input. This can be done by tying the audio (-) to the ground shield.
What does microphone sensitivity mean?
It is the microphone’s ability to convert sound into an electrical signal. The higher the sensitivity, the more easily it captures soft or distant sounds; the lower it is, the more it requires the sound to be loud or close.
It is measured in millivolts per pascal (mV/Pa) or in decibels (dBV), and helps choose the right microphone depending on the environment and the type of sound to be captured.
What is a dynamic microphone?
It converts sound into an electrical signal using a moving coil and a magnet. It is durable, does not require external power, and performs well in noisy environments.
Ideal for live performances and general public address use.
What is an electret microphone?
It is a variant of the condenser microphone that uses a permanently charged material. It is commonly found in small microphones such as lavaliers or portable devices.
It offers good sound quality in a compact size, although it requires power for its preamplifier.
What is a condenser microphone?
It uses a diaphragm and an electrically charged plate to capture sound with great precision. It requires phantom power (typically 48 V).
It is used in studios or situations where maximum sensitivity is needed.