Ever wondered what the numbers on condenser microphones mean?
Well, you’re in for a treat!
This article will answer the question, “What is phantom power?”, understanding the concept of phantom power more and what it does for the sound of the microphone.
Are you ready? Let’s dive right in!
What Is Phantom Power?
Phantom power is a method of providing power to microphones, more specifically condenser microphones. Phantom powering is in the form of DC voltage.
Phantom power provides DC power to the active components within certain active condenser microphones.
You can think of it as a way to send DC voltage through an XLR cable.
There is no power cable to show how the phantom power is supplied, which is how it got its name, “phantom,” meaning “ghost” or “invisible.”
What sets phantom power apart from other methods of providing power supply is it travels from the source through the same cable that carries the audio signal.
Through the XLR-3 connector and balanced cables, the power supply is delivered to condenser microphones.
Remember that Pin 2 and Pin 3 carry 48 V and 4 V DC, while Pin 1 is 0 V.
It is usually labeled as 48 V on most audio equipment such as audio interfaces, preamps, mixing consoles, and converters. However, it can also be labeled as 12V, 15 V, 18 V, and 24 V.
Phantom powering will result in identical voltage measurements between pin-2 and pin-1 and pin-3 and pin-1.
What Does Phantom Power Do?
Now that we understand phantom power, let’s discuss what it does next. First, we’ll tell you a little bit about how condenser microphones work.
The phantom power supply is commonly found in condenser microphones, as they have active electronics.
The distance between the diaphragm and the backplate changes as sound waves travel through the diaphragm.
This changes the capacitance of the condenser microphone.
The microphone input will not be translated into an audio signal without a proper power supply. Essentially, the condenser microphone is mute.
Condenser mics require phantom power to polarize the microphone’s transducer element, a.k.a, the capsule.
Once the phantom power supplies the needed voltage, the condenser microphone can translate the sound waves to the audio signal that audio software can read.
Phantom power supplies the needed voltage where you require it.
However, phantom power will not affect balanced dynamic microphones as there is no voltage difference.
How Does Phantom Power Work?
Since we understand the function of phantom power, let’s dive into the mechanics of the process.
Here, we’ll explain how phantom power is generated and supplied to the microphones. Let’s go!
Step 1: Production of Phantom Power
Phantom power is produced from electricity from the power mains or batteries that power the phantom power source.
This includes the following:
- Standalone phantom power supply units
- Microphone preamplifiers
- Audio interfaces
- Audio mixing consoles
What makes these sources possible of supplying phantom power is their active units that convert battery power into phantom power.
Step 2: Flowing Through Audio Cables
The Audio Engineering Society would agree that the positive voltage produced by phantom power sources will then pass through balanced audio cables.
XLR cables are wired with the following wires:
- Pin 1 = Ground/shield wire
- Pin 2 = Positive wire
- Pin 3 = Negative wire
Audio signals are sent down through Pins 2 and 3, with Pin 2 carrying the positive polarity mic signal and Pin 3 carrying the negative polarity version of the same signal.
With the two signals canceling each other out, noise or electromagnetic interference will affect both equally.
This means that the sound quality of the audio will not be affected.
Step 3: Voltage Travels to the Mic’s Output Connector
The voltage the phantom power will supply travels through the cable and towards the microphone’s connector to be prepared for use.
Passive microphones block the phantom power through an output transformer, such as in the case of some types of ribbon microphones.
Dynamic mics that have moving coils do not have an output transformer, but this will not be affected by phantom power damage.
Don’t worry, though!
Sending phantom power to a microphone that needs it is okay, even when you are not using the mic yet.
These microphones are designed to block the DC power voltage from entering circuits where it is not required or from reaching parts of the microphone that it may damage.
Step 4: Doing What the Mic Requires
Phantom power usually performs the following functions:
- Powering the impedance converter
- Powering the active circuit board components
- Polarizing the externally-polarized capsules
You can think of phantom power as the right amount of power supplied to the right components at the right time!
Of course, your condenser mic might not even require +48 V, but don’t worry! Your microphone is designed to adjust the phantom power depending on its needs.
If you want to find the true voltage output of your phantom power source, you can always check the specifications sheet of the device.
Alternatively, a voltmeter can be used to check the voltage across Pin 2 and Pin 1 and across Pin 3 and Pin 1.
Step 5: Turn the Phantom Power Off
Yes, you must turn phantom power sources off and on depending on your use.
Some equipment, such as audio interfaces and consoles, have their own phantom power switches for each channel.
Some older models of mixing consoles may have phantom power buttons.
Let’s Look Back: History of Phantom Power
Before the concept of phantom power, vacuum tubes powered microphones. This type of microphone can still be seen today in wired microphones.
Bell Labs invented the transistor in 1947, and scientists have found that they are smaller and require less power.
In the 1960s, manufacturers began using transistors in place of vacuum tubes, and they discovered that power could be supplied through the XLR cable carrying the mic audio.
In 1965, the CMT20 was produced by Schoeps, considered the first solid-state microphone.
In 1966, Neumann GmbH, an audio technology company, visited the Norwegian Broadcasting Corporation (NRK). They collaborated on the idea of a microphone running on Pins 2 and 3.
That same year, Neumann produced the CMV3, which is hailed as the first phantom-powered microphone in the world.
Does Phantom Power Make the Sound Better?
The phantom power supplies the needed DC voltage for the condenser microphone to work. It also powers up the preamp inside the mic.
Condenser microphones need phantom power to work, but this method DOES NOT affect your microphone’s sound quality.
Phantom powering is simply a method to power microphones through the XLR mic cable. To understand the question, “What is phantom power?” we must also know what it is not.
It is a type of power supply for microphones that require phantom power. However, phantom powering does not include noise reduction.
The mic signal will not be affected when your microphone needs an external power supply like phantom power unless the XLR cable malfunctions and the phantom power is affected too.
Do All Mics Need Phantom Power?
No, not all mics require phantom power to work. Passive microphones that do not have active electronics do not need it.
One example is a dynamic microphone. A dynamic microphone does not have any active circuitry like a condenser mic.
Dynamic mics use a different principle to generate sound. A dynamic microphone contains a mechanical moving coil that sends an electrical signal for recording.
Furthermore, dynamic microphones don’t need the +48V power like condenser microphones.
Another type of mic is ribbon mics. A ribbon microphone is a sub-category of dynamic microphones.
But, instead of a moving coil vibrating within a magnetic field, a ribbon microphone has an extremely thin strip of metal suspended in a strong magnetic field.
Some contemporary ribbon mics require an external power supply like condenser microphones.
However, be careful as some do not require +48V.
Frequently Asked Questions [Q&A]
Here are all the questions related to phantom power and other phantom-powered devices!
Is Phantom Power an External Power Supply?
An external phantom power supply rides on the same microphone cable that balances audio signals.
In that sense, phantom power voltage is a type of external power supply.
This is because a microphone has no batteries or will work independently. Phantom power is a powering method that does not involve batteries or any tangible source.
The volts DC are not sent through a physical mic cable that is required for tube microphones.
A phantom power supply is for devices that do not have their own microphone preamplifiers.
A plug-in-powered microphone or those that require DC bias voltage need a separate conductor from the cable carrying the audio output. This is usually the case for a dynamic mic.
Tube microphones require a separate power supply, such as being plugged into sockets or an audio interface.
Some true condenser microphones that get power from the tube require separate conductors for bias and audio.
Do Digital Microphones Require Phantom Power?
The analog-to-digital converters effectively convert the analog output into audio information, which is why they DO NOT need to apply phantom power to their process.
ADCs are found in USB microphones and other professional microphones used by YouTubers and other musically-inclined individuals.
Will Phantom Power Damage Dynamic Mics?
If your device is not a phantom-powered microphone and you accidentally send phantom power to it, there is no need to worry as it will not be damaged!
Most microphones nowadays are designed to accept phantom power without sustaining damage, even if they are not designed to be powered by it.
Even then, we recommend you read the manual properly, especially if the phantom powered input is of a high volts DC, such as +48 V.
Active microphones also risk sustaining phantom power damage if the DC power is inappropriate.
That’s why we recommend you check the voltage recommended for a microphone or equipment before plugging it in. A sudden overload may still cause some damage.
Turning phantom power off while plugging and unplugging microphones will prevent a sudden urge for electric power.
This will save your speakers, headphones, and audio interfaces from long-term damage over time!
Are Microphones Balanced or Unbalanced?
Unbalanced microphones consist of only two connectors containing two conductors for each connector.
These audio lines are used to connect instruments to amplifiers or portable recorders. These are not to be confused with the signal conductors in devices requiring phantom power.
On the other hand, balanced microphones are those that have three conductors containing three wires.
You may be curious, “What’s the difference, then?”
A balanced microphone uses the extra signal wire to filter noise through polarity inversion. They also have a longer cable length compared to unbalanced ones.
Balanced audio cables come in two connectors known as External Line Return (XLR) and Tip-Ring Sleeve (TRS) cables.
Analog and digital devices that require phantom power are equipped with XLR cables since this type of power runs through the same cable to power up the device.
Do I Need to Have a Preamp for Phantom Power?
Yes, microphone preamplifiers are one of the main phantom power sources, but you don’t have to buy one to use a condenser mic.
There is also another type of source called standalone phantom power supply units.
These are usually required if you want to plug in a mic to an input that does NOT supply phantom power.
You can find a wall plug and battery-powered standalone phantom power units.
Is Phantom Power Dangerous?
There are a lot of misconceptions surrounding the topic of phantom power and its safety. Phantom power is NOT DANGEROUS to humans.
It is called phantom power because it uses an existing cable inside a microphone to transfer power, which means that causing bodily harm to humans is out of the question.
What you need to know, however, is that phantom power can cause damage to microphones.
There are multiple situations wherein phantom power can cause damage.
- Firstly, electrical shorting. This can happen when the voltage is sent up on only one audio conductor rather than both. The voltage can enter the wrong components and cause damage.
- Another way is through power surges. The sudden spike in the electrical current after a brownout or a blackout can fry certain wires or active components in the mics.
- Lastly, unbalanced microphones may cause overload and have irreversible damage. Phantom power needs a balanced connection to work properly.
Again, it is NOT dangerous for humans, but microphones and other devices that utilize this powering method have a possibility of being damaged due to various circumstances.
What Can I Do to Avoid Power Surge?
If you are in a place where power shortages are common due to circumstances, it would be advisable to invest in power conditioners.
Power conditioners are devices used to protect sensitive loads, such as microphone wires.
They work by smoothing out voltage fluctuations such as spikes, transients, and electrical noise.
If an electrical outage happens and it immediately comes back, the sudden spike in the current will be smoothened out. This is important for phantom-powered devices.
Investing in power conditioners will not only be SAFER for your musical equipment but also ensure that they continue to function properly with their appropriate powering method.
What Is Digital Phantom Power?
To understand digital phantom power, we must first understand the concept of a digital microphone.
A digital wireless microphone transmits digitally-modulated waves towards a digital wireless receiver.
Instead of the usual analogue interfaces, a digital wireless microphone creates a waveform with only two values. The digital receiver understands this simple language.
Digital phantom power is not much different from regular phantom power, just that the power is sent via the XLR or the XLD connector.
The XLD cable is a variant of the XLR, but it has a different groove for connection, preventing the interchange of digital and analog devices.
Should I Use Phantom Power?
If you use a condenser microphone that requires phantom powering, the ONLY WAY for you to use the microphone is through phantom power.
However, if your microphone is not designed to receive phantom power, there are many other ways of powering up a mic.
These are some of the powering methods for microphones:
- T-power (A-B power)
- External PSUs
DC-biasing is a powering method for an unbalanced microphone usually supplied by wireless lavalier transmitters.
One of the methods for powering through audio cables, T-power uses resistors between the positive wire and negative wire pin.
Phantom power replaced this as it is safer for the mic.
Another type is plug-in power. These are mostly used for microphones that connect to audio equipment such as computer sound cards. It is a low-current source with a supply of +5 V DC.
External power units are for tube microphones. They act as converters and amplifiers for signals.
Battery-powered microphones can also be charged through one of the techniques above.
Do Miniature Microphones Require Phantom Power?
It is possible, but not necessarily.
The thing is, most miniature microphones are designed to connect with wireless transmitters.
These transmitters provide less than 10 V, which is not compatible with the voltage provided by most phantom-powered devices.
NOT ALL miniature microphones have XLR cables, which is crucial for transferring the current. However, adaptors are available to convert.
These conversion adapters change P48 to a relevant voltage that will power the miniature microphone.
For example, DPA miniature microphones work in the range of 12-48 volts.
Therefore, most miniature microphones do not require it, but there is a way for a miniature microphone to be a phantom-powered device.
My Condenser Mic Is Not Working. How Do I Fix This?
If your condenser mic is not functioning properly, there are multiple possible causes.
It may be true that one or more active component in your mic is not receiving the proper voltage that it requires or is simply dysfunctional.
If it is the first cause, the best thing to do is check the condenser microphone for the voltage and plug it properly.
If it is the second cause, then the best thing to do is to have it checked by professionals.
We hope you learned something from this article about phantom powering, how it works, and how it helps different types of microphones.
Phantom power might be a confusing concept to grasp at first, but it is important to understand how it works if you are in the music production industry.
Good luck and happy producing!