Phantom Power is a term given to the process of delivering DC (Direct Current) to the microphones which requires electric power to drive active circuitry. Condenser microphones are having active circuitry and require additional power to be operated.
Condenser Microphone won’t work if it’s simply plugged into sound Mixer or an Audio Interface without turning on the Phantom Power.
Phantom power, commonly designated as +48V or P48, was designed to power microphones without using bulky external power supplies such as the ones required for tube microphones. It’s a way of sending the DC electrical current required through a balanced XLR cable. In this Era of technology, the Phantom Power is available in most of the Sound Mixer and Audio Interface.
A dynamic microphone does not need any type of external power to operate. Another type of microphone is the condenser microphone. A condenser microphone needs external DC power to operate. Depending upon the design of the microphone, this power may be supplied by a battery, bus power from a computer, as well as several other methods, but quite commonly it is supplied by phantom power.
Phantom power sends the correct power (+48V) to a condenser microphone via an XLR socket and cable.
Only the appropriate microphone should be used with Phantom because if the microphone has a balanced output in which the voice coil or ribbon is NOT connected to mic ground, Microphone will not be damaged. If the mic has an unbalanced output because the voice coil or ribbon is shorted to mic ground, phantom could damage the microphone hence you need to be careful and specific while turning on the Phantom button in your sound Mixer and Audio Interface.
Why Condenser Microphone need Phantom Power?
condenser microphones have active electronics that need an external power source, while dynamic mics are passive and therefore do not need any additional power. Because of the way condenser mics work, their output is very high impedance, and therefore requires a powered circuit to reduce that impedance.