What is Phantom Power?
Phantom power, also known as simplex powering, is a DC voltage (generally ranging from 11 to 48 volts) that powers a condenser mic’s electronics and also provides a polarizing voltage for the capsule. In addition, different mics draw between 1 and 12 milliamps (mA) of current. Under most conditions, phantom power is supplied by a mixer, but it can also be supplied by a separate, dedicated power supply. Most contemporary condenser mics will work with phantom power voltages from 9 to 54 VDC. These mics include an internal power regulator that makes the mic operate successfully at whatever voltage you give it. Phantom power requires a balanced connection between the mic and power supply. This connection uses a three-conductor cable with XLR connectors on each end. The DC voltage is applied equally to pins 2 and 3 relative to pin 1, which is at ground potential. For example, if a recording console supplies +48V of phantom power, pins 2 and 3 each carry +48 VDC relative to pin 1. Of course,
. All condenser microphones require power to operate. In professional microphones, this power is supplied through the microphone cable via phantom powering. Phantom power is supplied either by • a standalone phantom power supply (such as the Crown PH-1A) or by • a mixer that has phantom power built in. The microphone receives power from, and sends audio to, the mixer through the same cable conductors. Let’s explain this another way. In a balanced microphone cable are two wires (conductors) surrounded by a shield. A DC voltage is applied to those two wires on pins 2 and 3 of the mic’s XLR connector. The audio signal uses the same cable conductors that phantom power uses. The audio signal is not affected by the phantom DC voltage since the signal is AC. Dynamic or ribbon microphones connected to a phantom-power input are protected from damage, theoretically, since the system results in a net zero DC potential across the coil or ribbon. However, if the dynamic or ribbon microphone is unba
A direct current (DC) electrical charge of some 9 to 48 volts that is sent along a microphone cable to energize the transducer is known as phantom power. The phrase “phantom power” is a result of the fact that there is no visible means of conductivity, no extra electrical line running from the DC power source to the microphone nor is the added DC voltage noticeable in the audio path. In other words, phantom power does its job of essentially powering the microphone invisibly and without interfering with the alternating current (AC) used for the actual audio reproduction and traveling in the same cable. Phantom power essentially energizes the diaphragm and capacitors inside a condenser microphone, also known as a capacitor microphone. Condenser microphones are today considered the microphone of choice for quality audio reproduction but require a DC power source for proper functioning. Power sources for this DC voltage include a mixing desk, a battery or a power box. Phantom power energiz
” I’m fairly certain there are a lot of us in recording who don’t really understand the differences between dynamic and condenser mics (other than “condenser mics sound better”). I know I was fuzzy on it, until I bought one and desired to learn how microphones actually work: Dynamic mics (the type you usually see for school assemblies, outdoor concerts, and such) function by using a barrier with a magnet attached. The barrier/magnet (generally referred to as a diaphragm) is next to a coil of wire. The movement of the magnet with a wire nearby produces a small electric current. This current is fed into a “preamp”, which makes that tiny signal much louder (bumps it up to what is called “line-level input”), and then you can record or hear it. Ribbon microphones function by a similar principle. However, rather than a robust circular diaphragm, they use a small ribbon with a magnet on either end. This makes them more sensitive to sound than a traditional dynamic mic, with some pleasant natu
