What is Phantom Power and Why Do I Need It?

What is Phantom Power Explained

If you are using condenser microphones in your home recording studio, chances are that you have heard of phantom power and why your condenser mics need them to sound properly.

Phantom power is essentially the process of supplying direct current (DC) through balanced XLR cables to power microphones that require electricity to operate active circuitry.

Which mics need phantom power?

Condenser microphones have active circuitry that requires an external power source, while dynamic mics are “passive” in nature and do not need any phantom power. Condenser mics have generally high impedance and require more power to reduce the impendence – which is why condenser mics tend to capture more detail in the music than dynamic mics.

For example, the Shure KSM32 condenser mic requires phantom power to operate, otherwise the signal will be too weak to be picked up by your studio monitors.

The term “phantom” refers to the lack of a visible power cable. This is because microphones that require phantom power are powered by the same cable that carries the audio signal.

How do you supply phantom power?

Phantom power is generated by drawing power from the source’s power supply, such as mic preamps, audio interfaces, mixing consoles, and standalone phantom power supply units.

Phantom power is typically +48 volts (on a DC input) and is designed to travel through balanced audio cables to supply power to the condenser microphone’s capsule and charge the backplate. Typically, your preamp will have a 48v button that allows you to toggle phantom power on and off (see example below).

PreSonus Studio 24c with +48V phantom power switch

Microphones are designed to take what they need and block what they don’t need from the supplied phantom power.

Is phantom power really necessary?

Condenser microphones generally require phantom power (for example, the Shure KSM 32s or the Rode NT1000) to power their internal active circuitry. If a condenser microphone does not have phantom power, the signal will be too “weak” to be picked up by your recording equipment.

On the other hand, dynamic microphones do not require any external power to operate. However, some low-output dynamic microphones, such as the Shure SM7B, require a preamp to boost the signal, in which case phantom power must be turned on.

As for ribbon microphones, it is recommended that phantom power be turned off because it may cause damage or a completely blown ribbon.

Will Phantom Power Damage My Microphone?

It depends on whether your microphone has active circuitry and electric components in the capsule.

Phantom power will not damage your dynamic microphone because they don’t have active circuitry inside them.

With that said, phantom power can damage condenser mics if too much voltage is supplied to the microphone and damages its active circuitry components. It is also best to turn off phantom power when plugging and unplugging microphones to avoid pops and loud noises that can damage your speakers or headphones.

Do audio interfaces supply phantom power?

Most audio interfaces such as the popular Focusrite Scarlett Solo (3rd Generation) or the PreSonus Studio 24c come with built-in preamps that supply phantom power to your microphones.

For example, the PreSonus Studio 24c includes +48V phantom power for condenser mics which you can toggle on or off.

Most condenser microphones require only up to +48V of phantom power. With that said, if you need more phantom power or a dedicated line for your condenser mic, consider getting a dedicated microphone pre-amp to amp your microphone channel. 

Next Steps

To learn more about home recording studio equipment, check out these posts:

Recommended Articles