Phantom power, an invisible energy, is a technological advancement that brings precision and transforms your listening experience. So, it’s required to bring clarity and smooth functioning of studio microphones.
Phantom Power is a DC supply (generally +48 V) to power the active circuitry inside the microphone with standard microphone cables. This electrical supply has standardized the phantom by transmitting audio signals within the same wire.
Table of Contents
What is Phantom Power?
The Phantom power is a standard for powering the “condenser microphones” via XLR cables and without additional power cables. The phantom power is supplied by mixing consoles, microphone preamplifiers, and audio interfaces.
Its name, “phantom power,” is derived because it can transmit audio signals and power the microphone from the same cable. Commonly, +48V is the standard DC power, while other phantom power ranges from 12-48 volts are also used. So, different common-use voltages include:
- +12 V DC
- +15 V DC
- +18 V DC
- +24 V DC
- +48 V DC
Its standard voltages power the active microphones’ active components and depend on the type of microphone. The power consumption varies with every microphone, and the phantom ensures a balanced supply.
Note: Not all active and modern microphones require phantom power to power their source.
How Does Phantom Power Work?
An external power supply, generally power phantom power and battery power, is insufficient to generate it. So, before moving to understand the working ability, it is essential to analyze the sources needed to supply the power:
- Audio Interfaces
- Audio Mixing Consoles
- Microphone Preamplifiers
- Standalone Power Supply Units
Audio Interfaces
Generally, audio interfaces can turn on or off the phantom power. This button is located on either side of the interface, and a simple click can turn on power for all channels.
Mixing Consoles
For professionals, it can power individual channels with a dedicated power button to power the whole console.
In smaller mixing consoles, the button with the name “+48 volts” is used to power the whole channel.
Preamplifiers
The standard and upgraded preamplifiers can power individual or whole channels with a simple click.
These power sources provide stable and balanced voltages to travel audio cables. Its invisible supply powers the active components of microphones via the XLR cables. With flat XLR cables, the voltage travels equally to pin-2 and pin-3 concerning pin-1.
The balanced microphone cable consists of three conductors to provide stable power to microphones. Also, these pins send positive and negative audio signals, and you find 0 volts DC.
Besides the balanced XLR, the TRS (tip, ring, sleeves) cables send stable +48 volts on the tip and ring concerning the sleeve. However, the XLR cables provide a professional audio experience and are generally used for extended periods.
Using the Balanced Audio Cables
Balanced XLR cables are commonly preferred for transmitting phantom power to active components inside the microphone. Also, the wires used in the cables are as follows:
- Pin-1 Ground wire
- Pin-2 Positive audio signal
- Pin-3 Negative audio signal
The audio signals from the microphone are sent down to pins 2 and 3, which travel parallel to each other. Since they are in a balanced cable, pin 2 carries positive audio signals and pin three negative signals.
Audio AC signals are sent down via balanced microphone input during sound pressure on the diaphragm. From there, the amplifier analyzes the difference between pins 2 and 3, where the resulting signal is the sum of two signal inputs.
Also, similar signals got canceled with phantom power common mode rejection, which does not affect the output. With this, it will neither add nor have any effect on audio signals and transmit unaffected sound.
Powering the Microphones
With a balanced XLR cable, phantom power transmits a stable supply to power the active components of microphones. The voltage travels from the microphone input to the mic output without affecting the audio signals.
Therefore, the microphones are designed to send phantom power where required, and circuitry is designed to stop it where it is not needed. It’s essential to prevent the sensitive microphone components from damage.
- Transmitting the Power
After turning on the phantom power, the necessary DC voltage travels from the balanced XLR cable (3-pin conductor cable) to power the microphone. For condenser microphones with active electronics, phantom power is a dynamic powerhouse.
Also, the working of phantom power microphones is completed in a step process:
- After turning it on, the current leaves the phantom power-positive terminal and travels along the balanced mic cable to the microphone.
- Current travels through mic circuitry and powers up the diaphragm inside the mic.
- Then, the current returns to the negative terminal power supply via the same mic cable.
In True Condenser Microphones, where voltage is also required to polarize the transducer elements, phantom power provides sufficient supply.
- Turning on or off the phantom power
All modern consoles and preamplifiers can power on or off to supply voltage to individual channels. A simple power button ensures sufficient supply to power the microphone without affecting the audio signals.
Besides the standard +48 volts requirements, the microphone also required different voltages depending on their design. So, the mic is designed to adjust their phantom power requirements, ensuring the entire supply and avoiding adverse effects on the microphones.
Types of Microphones and Their Phantom Power Usage
Specifically, condenser and active ribbon microphones require phantom power to supply the microphone. Generally, active microphones, both condenser and dynamic, need phantom, and passive microphones don’t require phantom power.
However, microphones have been divided into two categories: microphones require and do not need phantom power.
Microphones That Require Phantom Power
All condenser microphones with active circuit components require a standard 48-volt supply to power and amplify the signals. Condenser’s diaphragm is a thin plate that works efficiently with phantom power. Hereunder is the detail of microphones that require phantom power:
- True Condenser Microphones
True Condenser Microphones are required to externally polarize the capsules and generate electrical signals similar to sound waves. So, phantom voltage is needed to charge the diaphragm and backplate and ensure the impedance converters.
- Electret FET Condenser Microphones
“Electret condenser,” “Internal bias,” or “DC-biased” are known when mics are charged by electret material in the diaphragm. However, for some microphones, phantom power is required for impedance conversion and powering the active components of the mic.
Some lavalier or choir mics work on the DC-biased principle designed with charged electrical material. This permanent charge material in the mic does not require phantom power.
Note: In some active circuitry components, the phantom is in a dynamic gradient to power the mic electret circuitry.
- Active Ribbon Dynamic Microphones
Most ribbon microphones are passive, with a thin metal plate between the magnets to convert the sound into electrical signals. This electromagnetic induction is essential to supply the voltage and transmit signals.
Microphones That Do Not Require Phantom Power
Dynamic or Passive microphones, where audio waves are turned to electrical signals using magnetic fields, do not require phantom power. The sound is converted to electrical energy that creates voltage depending on received signals.
So, hereunder is the detail of the mic that can work effectively without phantom power:
- Moving Coil Dynamic Microphone
In the moving coil, the wire coil is attached to the microphone’s diaphragm and suspended in a magnetic field. Therefore, this electromagnetic induction is a passive electrical process and does not require phantom power for any active components.
- Passive Ribbon Microphones
Unlike active ribbon microphones, it works on the passive electromagnetic induction principle, not needing any external power. So, passive ribbon microphones do not have active circuitry and need only magnetic ability to perform efficiently.
- Tube Microphones
Tube microphones have a smaller portion of active electronic components, but they come with their dedicated power supply. It happens because these microphones require higher voltage for heating the tube for which phantom power is insufficient.
| Type of Microphone | Does it require Phantom Power? |
| Modern Condenser Microphone | Yes |
| Battery Powered mics | No |
| Active Ribbon Mics | Yes |
| Passive Ribbon Microphones | No |
| Dynamic Moving Coil | No |
| Tube Microphones | Yes |
| Electret condenser (FET) – small components | No, DC-biased power supply |
| Electret condenser (FET) – large components | Yes |
| USB Microphones | No |
| Digital Microphones | No, but for additional power |
Phantom Power Standards
Phantom power is standardized under the International Electrotechnical Commission Standards Committee (ICE). The documentation named under the “Multimedia Systems Guide” has set specific parameters and standards for phantom power supply.
The IEC 61938 Standard Guide defined three different voltages:
- P12 (12-volt DC)
- P24 (24-volt DC)
- P48 (48-volt DC)
The P12 and P48 variants are still in use, which provide exceptional values to the microphones. However, the standard recommends a 24-volt system in new-generation microphones to enhance overall performance.
And, with phantom power positive signal conductors, it provides the following equal value resistors:
- 680 Ω for 12 V
- 1.2 kΩ for 24 V
- 6.81 kΩ for 48 V
Due to the resistors’ (6.81 kΩ) nature, the resistors must be matched within 0.1% or better to enhance or maintain perfect common-mode rejection (CMR).
Along with the abovementioned variants, there are some other hereunder recommended types:
- P12L (low-power applications)
- SP48 (super-power applications)
Is Phantom Power Dangerous to Microphones?
Modern dynamic microphones are designed to accept phantom power and do not cause any damage to microphones. However, improper handling can cause damage to microphones and doesn’t cause any bodily harm.
Plugging your dynamic or condenser microphone from the electrical outlet will destroy the mic’s circuitry. Turning off phantom power before and after plugging in the mics is recommended to prevent damage. The potential damage due to improperly using the phantom power includes:
- Power Surging
- Electrical Shorting
- Using Unbalanced Cables
- Damage through Power Surging
Sudden power surges can overload the phantom power circuitry, destroying specific sensitive microphone components. So, it’s the case with ribbon microphones because of their sensitivity, and surge can cause potential damage.
The best practice is to turn off phantom power before and after plugging on or off to avoid damage-associated risks.
- Damage through Electrical Shorting
Phantom power is explicitly designed to send delicate equal voltage supply to necessary components. However, with an improper power supply, the power supply can go up or down on one conductor.
This electrical shorting is why the current enters and damages the sensitive components of the microphone.
- Damage due to Unbalanced Microphones
Unbalanced microphones are the result of using unbalanced cables to transfer DC voltage. The phantom power works with Balanced Cables, and an unstable connection provides electrical shorting that damages the mic.
Phantom Power and Dynamic Microphones
Modern dynamic microphones will not hurt or get affected by 48 V phantom power. The mic symmetry is designed in such a way as to accept phantom if needed or stop it if it isn’t required.
The dynamic mic is transformerless but can effectively handle phantom power if applied. However, ribbon microphones have a sensitive diaphragm, and their output transformers are designed to protect them from DC voltage.
So, output transformers only allow AC voltage and efficiently prevent damage by phantom power. In addition, the mic is likely to get damaged when unbalanced cables transmit improper supply to power essential functions.
- The lavalier and karaoke mics do not have XLR connectors and do not need phantom for their work. However, modern wireless receivers have built-in phantom power blockers to prevent them from any potential damage.
Phantom Power vs. Battery-Powered Microphones
Some microphones can be powered by phantom power or the microphone’s internal batteries. However, removing the batteries before phantom powering is recommended to avoid leakage or corrosion.
The concerning issue is damage to the batteries because of high phantom voltages, but removing them can save them.
What is Digital Phantom Power?
Alongside the standard phantom power, the Audio Engineering Society (AES) has published a specific set of standards for digital microphones. Digital mics that comply with standards will run on 10-volt DC phantom power.
This 10 V DC power current must be up to 250 mA to supply necessary working power to digital microphones. The digital phantom power is delivered the same way as the standard phantom, which is why the majority of P-48 analog sources are unable to provide a 10 V supply.
Due to this reason, another efficient XLR variant XLD connector provides an exceptional opportunity to supply digital phantom.
- The XLD has the same balanced cable setup, and it helps to prevent the interchange of analog and digital devices.
Benefits of Using the Phantom Power
Phantom power is designed primarily to power microphones in a balanced output cable without using bulky external supplies. It’s essential in powering the internal preamplifiers and impedance converters of active components of mics.
Alongside this, phantom power +48 V is the global standard because of the following underlined reasons:
- No Batteries Required
Phantom power provides enough for studio microphones without batteries or an external power source. It makes the mic possible to send a +48 volt power supply with a balanced XLR cable.
Its primary advantage is that it allows for high-quality audio recordings without needing external supplies. It happens because it can transmit seamless signals and the necessary voltage to power the active components via the same cable.
- Clear Signals
Generally, the clean and required supply ensures that the sound is stable and without any distortion. However, if the XLR cable is damaged or the audio interface is broken, this will lead to increased signal-to-noise ratio issues and distorted audio. It also happens when an inefficient power supply is required to deliver the signals.
By eliminating these issues, phantom power will deliver the necessary voltage and improve audio quality by eliminating unwanted audio.
- Cost Effective
Phantom power is the cost-effective solution for powering the studio mics without needing external power supplies. It uses lower electricity consumption, as is the case with ribbon microphones.
Phantom power is an efficient way of powering the microphones without needing external power supplies. The mic is an exceptional choice for home or portable studio setups with no additional power source.
- Simple and Easy to Setup
It simplifies the installation process with its more straightforward setup of audio equipment. Also, because there’s no additional setup required, it can supply power and signals from the same balanced cable with just one click from your audio equipment.
Are Microphones That Require Phantom Power Better Than Those Mics That Don’t Need?
It depends on the type and the intended use of the microphone because certain mics work best under certain conditions. However, phantom power has several advantages over others, and these are specified hereunder:
- Lower Signal to Noise ratio
Using phantom power means that the microphone has active electronics to amplify the signals in a balanced cable. During amplification, keep your mic antenna as close as possible to (~1cm) the transducer to avoid noise pickup.
Also, it ensures lower noise pickup from the surrounding environment, making the microphone output 15-30dB hotter. It makes it compatible with transmitting power supply without disrupting the audio signals.
- Microphone Load Optimization
Microphone active electronics also indicate that the load on the mic capsule can be optimized. It ensures impedance for the flattest frequency response and minimizes voltage and current noise.
The standard frequency response is essential; internal preamplifiers modify it for accurate mic pads and filters. This enhanced feature of phantom power makes the microphone distinguishable from other mics.
- Multi-pattern Microphone
Phantom microphones are better multi-pattern mics for professionals who use omni and multi-channel. Besides, a mic with a lower impedance for long cables will minimize the gain. The preamplifiers with reduced mics gains ensure lower noise and minimize the audio distortions.
Why Phantom Power Should Not Be Used?
Although Phantom Power provides exceptional audio solutions, there are many reasons why it is not a complete solution:
- In some cases, amplification and impedance matching cannot do the job, and transformer mics better understand these situations.
- Phantom microphones are limited only to studio and portable microphones and are unable for live performance.
- Also, plugging in or off the phantom power without muting the microphone will result in loud cracks that damage amplifiers or speakers.
- Plugging the microphone into hot microphone outputs will damage the microphone gears.
- Phantom power has three standard voltages; using the wrong supply will permanently damage the mic. So, before switching the phantom power, turn off the DC volts and read the mic manual for specific mic types.
So, the right microphone for the right job is the key that should always be considered before using the mic. However, microphones with active circuit components are the perfect choice to deliver quality with perfection.
Final Thoughts
Phantom Power is DC +48 volts that power the active components and amplify the audio signals. Specifically, condenser microphones have active ingredients to power their source in a balanced output cable. The phantom power is more prone to damage that will negatively affect the mic, and it’s best to read the microphone’s manual before applying.
Additionally, using the correct voltage for the right microphone will enhance your recording experience. For safe practice, always turn off when you do not need phantom power and mute the mic before turning it on or off.
