Best microphones pick-up sound waves and convert those waves into an electrical signal to be used by audio equipment in one of two ways.
A dynamic (or moving coil) microphone operates using a wire coil as well as a magnet to generate the audio signal. The interaction of the wire coil and magnet is referred to as electromagnetic induction and is responsible for generating an output signal voltage. A diaphragm is attached to the coil, and it is mounted in the mic to ensure that it can move around in reaction to a solid wave. Once the diaphragm vibrates, the attached coil moves backwards and forwards within the magnetic field. This motion within the field generates an electric powered current (induction), which can be converted by audio equipment into sound waves. The potency of the electrical current is directly related to the motion in the coil.
Dynamic mics are wonderful general-purpose microphones. They may have less moving parts than condenser mics, and as a result they’re typically more rugged and sturdy. Additionally, because they generate their very own current, no external source of energy is needed.
The physics behind the moving coil can contribute to limitations in frequency response. Most of the time, dynamic microphones are less sensitive than condenser mics.
In a condenser microphone a voltage charge is used towards the diaphragm by either a battery or phantom power. The diaphragm is mounted not far from a stationary back plate. Sound waves striking the diaphragm causes it to move closer and farther from the back plate which causes electrical charge fluctuations to take place. The interaction between the diaphragm and back plate creates an electric component known as a capacitor (or condenser), and also the resulting variations in voltage can be reinterpreted as sound waves from the receiving audio equipment.
Condenser microphones are extremely responsive and create a much stronger signal than dynamic mics. This will make them an ideal choice for professional settings such as studio work, where it’s important to pick up vocal subtleties.
Typically Condenser Microphones get more moving parts than their dynamic counterparts and they are less durable. Also, since they do not generate their very own current they might require another power source. (Battery or phantom power)
What exactly is phantom power? Phantom power is actually a direct current (typically between 12 and 48 volts) that supplies microphones with power through audio cables. 48 volt phantom power is the most common and is often tihdsy by microphone preamps and audio mixers.
The pickup pattern is most likely one of the most crucial elements when choosing a mic. The pattern determines which directions will and won’t pick up sounds. Pickup patterns for vocal microphones typically belong to the subsequent categories: omnidirectional, unidirectional and bidirectional.
Omnidirectional mics get sounds coming from all directions equally while a unidirectional mic was created to only pick-up sound from one direction. Bidirectional mics are rarer, and are designed to pick up from two sides – beneficial to a two person podcast when sharing a single mic. “Cardioid” is another term often used when describing the pickup patterns of microphones. A cardioid mic picks up sounds from the front, however, there is some limited pickup through the sides. It will help to offer some tolerance for sideways movement of the speaker while recording.
Accessibility to power is another consideration for podcasting microphones. Most studio vocal microphones (condenser type) require phantom power – which means external power needs to be provided to the gear. This is most often accomplished using mixers and mic preamps. USB microphones on the contrary, have the ability to connect straight to a pc without requiring an outside power source. Dynamic mics are generally less sensitive but usually do not demand a power source.