4 Types of Microphones that Require Phantom Power
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Microphones are essential tools in the realms of audio recording, broadcasting, and live sound reinforcement. Among the different types of mics, those that need to have phantom power are particularly notable. Knowing which types of mics need phantom power can help in selecting the right equipment for specific recording and live applications.
Which Microphones Need Phantom Power?
Out of all the microphone types, there are certain ones whose external phantom power supply needs phantom power. Specific microphone types that need phantom power are condenser microphones, electret microphones, active ribbon mics, and tube mics. Let’s delve into each of these types and understand why these mics need phantom power.
Condenser Microphones
Condenser microphones (or capacitor microphones) are the most common type of mics that need to have phantom power. They operate on an electrostatic principle (variable capacitance), using a capacitor to convert acoustic energy into electrical energy. The diaphragm of a condenser microphone is mounted very close to a backplate, and the space between them forms a capacitor. Thus, they are also called capacitor microphones as they use variable capacitance.
When sound waves hit the diaphragm, they vibrate, altering the distance between the diaphragm and the backplate, which in turn changes the capacitance. This change in capacitance is converted into an audio signal. However, for this process to occur, the condenser microphone needs a continuous power supply to maintain the electrical charge between the diaphragm and the backplate. This is where phantom power comes in.
Phantom power is supplied to condenser microphones via the same XLR cable that carries the audio signal. This design is both efficient and convenient, as it eliminates the need for a separate power cable and microphone cables.
There are various types of condensers, including large-diaphragm condensers, which are often used as studio mics for vocals and acoustic instruments in studio settings due to their ability to capture detailed and nuanced sound. Small-diaphragm condensers are also widely used, particularly for recording instruments with high transient response, such as drums, cymbals, and string instruments. Some popular examples of condensers that require an external power supply include the Audio-Technica AT2020, Neumann U87, and Rode NT1-A.
Electret Microphones
Electret microphones are a subset of condenser microphones, distinguished by their use of a permanently charged material to maintain the necessary electrostatic field. This permanent charge reduces the dependency on an external source to some extent, but these mics need phantom power for their internal preamplifier.
The electret diaphragm is made from a material that holds a static charge, but the built-in preamplifier needs power to function properly. Phantom power provides this necessary voltage, allowing the microphone to amplify the signal to a usable level.
Electret microphones are often found in applications where compact size and low cost are important. They are widely used in lavalier microphones, headset microphones, and some handheld microphones. Despite their smaller size and more affordable price, electret microphones can offer excellent sound quality, making them popular choices for both amateur and professional use.
The Shure SM93, Audio-Technica AT803, and Sennheiser ME 2 are all examples of electret mics that need phantom power.
Active Ribbon Microphones
May it be traditional or modern active ribbon microphones, these types are known for their smooth, natural sound. As such, they are often used as studio mics for recording vocals, guitar amps, and brass instruments.
Modern active ribbon microphones have become increasingly popular. Modern active ribbon microphones combine the classic sound of ribbon mics with modern active electronics requiring phantom to operate.
An active ribbon mic has a built-in preamplifier that boosts the microphone’s output signal, making it more compatible with a wider range of preamps and audio interfaces. This internal amplification helps to overcome one of the traditional ribbon microphone’s limitations: low output levels. The internal preamp is powered by phantom power, which enhances the microphone’s performance and makes it easier to use in various recording and live scenarios.
Examples of active ribbon mics that need phantom power include the Royer R-122, AEA R84A, and Audio-Technica AT4081.
Tube Microphones
Tube mics, or valve microphones, are a special category that also benefits from phantom power. These microphones use vacuum tubes to amplify the audio signal, which imparts a warm, rich quality that is highly sought after in vocal and instrumental recordings.
While tube mics typically come with their own dedicated power supplies to provide the necessary high voltage for the tube, they still often require phantom power for other internal components, such as the microphone’s internal active circuitry, internal amplifier, or capsule polarization.
The combination of tube amplification and phantom power allows tube mics to deliver their signature sound while maintaining the convenience and functionality of modern microphone systems. These microphones are prized in studio environments for their unique tonal characteristics and ability to add a pleasing warmth to recordings.
Notable examples of tube microphones include the Neumann U67, Telefunken ELA M 251, and AKG C12, each of which incorporates phantom power alongside its tube-based design.
Do All XLR Mics Need Phantom Power?
To determine whether all XLR mics need phantom power, it’s essential to delve into the specifics of microphone types and their power supply requirements. XLR, or External Line Return, refers to the type of connector and cabling used for professional audio equipment. This robust, balanced connection is designed to reduce noise and interference, making it the standard choice for high-quality audio applications.
However, the need for phantom power is not dictated by the use of an XLR cable or connectors alone but rather by the internal design and circuitry of the mic.
Condenser Mics
Condenser mics need phantom power. These mics operate based on an electrostatic principle, needing a voltage to maintain the electrical field between the diaphragm and the backplate. Phantom power, typically provided at 48 volts, is supplied through the same XLR cable that carries the audio signal. This method is both convenient and efficient, eliminating the need for separate power cables.
The need for phantom power in condenser mics arises from their internal components. The diaphragm and backplate form a capacitor that converts sound waves into electrical signals. This conversion process requires a constant electrical charge, supplied by phantom power, to function correctly. Without this phantom power, the microphone would not produce an output signal. Therefore, all condenser mics using XLR connectors do require phantom power.
Dynamic Mics
Dynamic microphones, on the other hand, do not require phantom power. Dynamic microphones operate on an entirely different principle, utilizing electromagnetic induction to convert sound waves into electrical signals. The diaphragm of a dynamic microphone is attached to a coil of wire, which is suspended within a magnetic field. When sound waves hit the diaphragm, it moves the coil within the magnetic field, inducing a direct current that mirrors the sound wave.
Because this process does not rely on an electrical field, dynamic microphones do not need to have phantom power. They are passive devices and can function purely on the mechanical energy of the sound waves. This independence from phantom power makes dynamic microphones highly versatile and durable, suitable for various applications, including live reinforcement and instrument miking.
Examples of popular dynamic mics that use XLR connectors but do not necessarily phantom power include the Shure SM58 and the Sennheiser MD421. Do take note that the SM58 does not have active electronics inside.
Ribbon Mics
Ribbon mics, particularly the traditional passive types, also do not require phantom power. These traditional ribbon microphones do not require an external phantom supply, and in fact, applying phantom power to them can damage the delicate ribbon element. When sound waves strike the ribbon, it moves within the magnetic field, generating a voltage or DC current. This process is similar to that of dynamic mics and does not necessitate an external phantom source.
Thus, do be wary of using phantom power on passive ribbon microphones. Using a phantom power of +48V with your passive ribbon microphone can destroy it. As such, make sure that you only use enough power to crank up your passive ribbon microphones.
However, it’s crucial to note that active ribbon mics, a modern variant, do require phantom power. These mics incorporate active electronic components, such as built-in phantom power and preamplifiers, which need an external power supply to operate. Phantom power supplies the necessary voltage to these internal circuits, enhancing the microphone’s output level and compatibility with various audio equipment.
Tube Mics
Tube mics are another category where the power requirements can vary. These mics typically use vacuum tubes to amplify the audio signal, giving them a distinct, warm sound. Most tube mics come with dedicated power supplies that provide the high voltage or DC current needed for the tube’s operation. However, some tube microphones also use phantom power for their internal circuitry or capsule polarization.
Final Note
Understanding which microphones require phantom power is crucial for anyone involved in audio recording. Condenser mics, electret microphones, active ribbon microphones, and tube microphones are the primary types that depend on phantom power for their operation.
Frequently Asked Questions
Does the SM57 mic need to have phantom power?
The Shure SM57 is a dynamic mic and, as such, does not require phantom power. Dynamic mics operate based on electromagnetic induction, which involves a diaphragm attached to a coil of wire that moves within a magnetic field to generate an electrical signal. This process does not require an external power source, making dynamic mics like the SM57 inherently passive devices.
The Shure SM57 mic is renowned for its versatility and durability, widely used in both live and studio recording settings. It is particularly favored for miking instruments such as drums, guitar amplifiers, and brass instruments, thanks to its ability to handle high sound pressure levels and its focused frequency response.
Because the SM57 mic does not need to have phantom power, it can be used with any standard XLR mic input without concern for supplying external voltage. This feature adds to its convenience and reliability, ensuring an optimized performance across a wide range of audio environments.
What is the power source of dynamic microphones?
Dynamic microphones do not require an external power to operate. Their functionality is based on the principles of electromagnetic induction, which allows them to convert sound waves into electrical signals without the need for additional power.
Does a condenser microphone have bulky external power supplies?
No, most modern condenser microphones do not have bulky external power supplies. Instead, they typically use phantom power, which is supplied via the same XLR cable that carries the audio signal. Phantom power is usually provided by audio interfaces, mixers, or preamps, making the setup more streamlined and convenient. However, some high-end condensers, particularly tube condenser microphones, might come with their own dedicated external power supplies.
What supplies phantom power?
Phantom power is supplied by audio interfaces, mixers, or preamps. These devices provide the necessary voltage, typically 48 volts, through the same XLR cable that carries the audio signal to power condenser microphones and other active audio equipment.
An audio interface serves as a bridge between analog audio signals and a digital audio workstation (DAW) on a computer. It converts the analog signals from a mic and instruments into digital data that can be recorded, edited, and mixed on a computer, and then converts digital audio from the computer back into analog signals for monitoring through speakers or headphones. Popular audio interfaces include the Focusrite Scarlett series, PreSonus AudioBox, and Universal Audio Apollo series.
Mixers are active electronics that combine multiple audio signals, adjust their levels, apply effects, and route the mixed output to speakers, recording devices, or other destinations. They are commonly used in sound reinforcement, broadcasting, and even in a home recording studio setting.
Preamps, short for preamplifiers, are devices that amplify low-level audio signals from a mic and instruments to line level. High-quality preamps are crucial for capturing detailed and clear audio, especially in professional and home recording settings.
Do microphones have active circuitry?
Yes, some mics do have active circuitry. This primarily applies to certain types of mics designed to require external sources, such as a condenser mic, active ribbon, and some tube mics.
Active circuitry in mics refers to the inclusion of electronic active components that require an external power to operate. These active circuitry components typically include preamplifiers, impedance converters, and other electronic elements designed to enhance the microphone’s performance. The presence of active circuitry distinguishes these microphones from passive microphones, which rely solely on mechanical transduction methods without the need for power externally.
On the other hand, internal active circuitry refers to the built-in electronic active components that require power sources externally. Types of internal active circuitry devices are preamps and impedance converters.
What is the global standard for phantom?
The global standard for phantom is +48 volts. This voltage is supplied through XLR cables to crank up condenser microphones and other active audio equipment that require power to operate. The same can be said for the industry standard.
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