What is Phantom Power?
For many, audio is one of the most confusing elements of video production. Why do some microphones work with anything they are plugged in to? Why are there some that never seem to work unless they are plugged into an audio mixer? What is the 48+ on the audio mixer mean? Below, Paul Terpstra from Klover Products, INC demystifies phantom power.
What is phantom power?
Did you know that many microphones require a power source, just like your toaster? In addition, there are two different requirements depending on which microphone you are using, Phantom Power or Plugin Power. That can be confusing!
Phantom power is a way of providing power to a device, such as a microphone, through the same cables that are used to transmit the audio signal. In other words, phantom power allows you to power a device without the need for a separate power supply or battery.
Phantom power is often used to power condenser microphones, which require a constant source of power in order to operate. The power is typically provided at 48 volts DC but can be as low as 12 volts. Phantom power is usually supplied by an audio recorder, camera, mixing console or a dedicated phantom power supply. As previously mentioned, the power is transmitted to the device through the same cables that are used to transmit the audio signal.
To use phantom power, the device must be equipped with a phantom power input, which is typically a 3-pin XLR connector. When phantom power is applied, the device can draw the necessary power from the cables, allowing it to operate without the need for a separate power supply.
Benefits of using phantom power:
The benefits of using phantom power include the ability to power devices remotely, the ability to power multiple devices through a single cable, and the ability to use devices that may not have their own power source. Additionally, because the power is transmitted through the audio cable, it eliminates the need for an external power source or battery, which can be more convenient and reduce clutter.
Because XLR cables are typically constructed of shielded, twisted pair cable, they resist electrical noise better than non-balanced, or two conductor microphones.
Cons of using phantom power:
The downside of using phantom power include the potential for interference or noise in the audio signal if the cables are not shielded or properly grounded. Additionally, not all devices are compatible with phantom power, so it may limit the types of devices that can be used in a given setup.
Another downside is that using phantom power can cause damage to certain types of microphones, such as ribbon microphones, which are typically not designed to be powered in this way.
It’s also worth noting that phantom power may not be available on all audio interfaces or mixers, which could limit the flexibility of the setup and make it difficult to use certain devices.
Lastly, using phantom power may require additional expense to purchase equipment that is compatible with it.
Conclusion:
The lack of required power is one of the most common reasons a microphone is not providing a signal, as the external power has to be turned on manually on most devices. Be sure to verify that your microphone is receiving the required power if you are not receiving a signal.
Meet the Author, Paul Terpstra
Paul spent the first 30+ years of his career with nearly every aspect of automated industrial equipment. After spending nearly 20 years working for a builder of custom assembly automation equipment, he formed an engineering consulting firm specializing in industrial equipment. The focus of that company expanded to forensic engineering and ultimately to serving as an equipment expert supporting legal cases.
In 2011, he was asked to design a parabolic microphone. That design ultimately led to his co-founding Klover Products, Inc. Since that time he has been an avid student of audio (which he had played with previously) and the problems facing the broadcast / production industry.
Adam, your resident IB film teacher, wants to help your students walk the talk. How understanding the Big 4 (mise-en-scene, editing, cinematography, and sound design) can transform student analysis and filmmaking.