The magnetic fields generated by the current through the voice coil interact magnetically with the magnet of the speaker’s magnetic fields, causing the coil and the attached cone to move backward, producing sound output.
Because life is becoming more modern and advanced, microphones are more important than ever. This is why many people are interested in how a microphone works.
This article will explain the workings of the microphone, how it generates an electrical energy signal and how it converts it to it. Let’s get started!
No sound was ever recorded until the mid-1800s. The sounds we hear are a one-time event that disappears into thin air as fast as it was produced.
A revolution that would bring us the audio signal was possible thanks to the genius of a few curious thinkers. Although audio technology is something we use every day, it was not possible back then. However, the fundamental ideas of sound recording and reproduction remain unchanged.
The microphone is the heart of this revolution. Microphones can convert the sound energy into an electrical energy signal, which can then be recorded, modified, distributed, and broadcast back into the air.
Different microphone types have different sounding characteristics and can be used for different purposes. We will explore the various microphone types, and their directions (polar patterns), and common problems encountered when using them.
Maybe You Need: When Was The Microphone Invented? Top Full Guide 2021
Microphones Are Loudspeakers In Reverse
Most people don’t realize that microphones and loudspeakers look so different. You’ll have read our article about loudspeakers, and you will already understand how microphones work. They’re loudspeakers that operate in reverse.
A loudspeaker transmits electricity to a coil made of metal wire wrapped around or in front of a permanent magnet. The coil’s changing patterns of electricity creates a magnetic field around it, which pushes against that created by the permanent magnet.
This causes the coil to move. The coil is attached to a flat disc called a cone or diaphragm. As the coil moves, so does the diaphragm moves too. The diaphragm moves air into the room, creating sound waves that we can hear.
Although they look almost the same in a microphone, they function exactly the opposite way.
How A Microphone Works
How does a microphone convert sound energy into electricity? As this:
- Your voice creates sound waves that carry energy to the microphone. Keep in mind that the sound we hear is energy carried by vibrations within the air.
- The microphone’s diaphragm is much smaller than a loudspeaker, and it moves back and forth as sound waves hit it.
- The coil attached to the diaphragm also moves back and forth.
- A permanent magnet creates a magnetic field that cuts through the coil. An electric current flows through the coil as it moves through the magnetic fields.
- The microphone works to transmits the electric current to an amplifier or sound recorder. You’ve now converted your original sound to electricity. You can store your original sound forever by using the current to drive sound record equipment. You could also amplify (boost) the current, then feed it to a loudspeaker. This will turn the electricity into a much louder sound. This is how PA (personal address), electric guitar amplifiers, and amplifiers for rock concerts work.
Dynamic Microphones: How do they work?
The simplicity and strength of dynamic microphones make them a valuable addition to any engineer’s mic collection. Dynamic microphones use electromagnetism to produce an electric signal. This is a theory of physics in which an electric conductor moves in magnetic fields.
The diaphragm of dynamic microphone, a component that reacts to vibrations in the air, is attached to a coil made of wire and surrounds strong magnetic fields. The coil’s interaction and magnet of dynamic microphones create an electric signal when sound is applied to the diaphragm dynamic microphones.
The physics behind this process can seem complicated, but the parts of the dynamic microphone that make it possible have simple and durable components. Dynamic Microphone is also less sensitive to high-pressure sound than other types of microphones.
Dynamic microphones are a reliable and durable option for recording loud sources such as explosions, drums, amps, etc.
Condenser Microphones: How do they work?
Condenser microphones, also known as capacitor microphones, are a popular type of microphone. This circuit has a diaphragm sitting near a metal plate. An electrical charge is created when the microphone is connected to an external power supply source or a battery.
Sound waves are striking the diaphragm cause it to vibrate back and forth closer and farther away from the static backing plate. This alters the current between the two components and creates a flow of sound.
The output signal represents the diaphragm changing its default position. The signal is not strong enough to travel to the next equipment in the audio chain, so additional components are added to amplify it before it leaves the condenser microphone.
Phantom Power In Condenser Microphones
A condenser microphone is used to require special cables and an external power supply to function. However, today’s condenser microphone is more common to see power coming directly from the microphone input of a mixer, console, or audio interface (labeled 48V, Phantom Power, or simply 48V) rather than a standard XLR cord.
It is important to note that the condenser microphone works still comes with an external power supply. This is because the condenser microphone can accommodate a sufficient phantom power for an amplifier component known as a tube.
However, tubes have been replaced by solid-state electronic microphone technology in modern technology.
The Benefits Of Condenser Microphones
A condenser microphone works with no coil attached to its diaphragm, so it vibrates more freely than a dynamic microphone. Condenser microphones can accurately represent incoming sound waves with greater detail and nuance, thanks to this. Condenser Microphones are the best choice for a studio recording with high fidelity.
Fair warning: Many condenser microphones are cheaply made and can produce unfavorable results. Do your research about condenser microphones before you make any decision!
Ribbon Microphones: How do they work?
The ribbon microphone is a typical dynamic microphone that uses different components to achieve the same electromagnetic process.
A diaphragm or coil ribbon microphone is replaced by a thin aluminum sheet or aluminum alloy. It suspends between a magnet and does both of these jobs!
Condenser microphones and dynamic microphones react only to fluctuations in the surrounding air pressure. Ribbon microphones, however, respond to the velocity and are often referred to simply as velocity microphones.
Ribbon elements can handle different frequencies differently and produce a more natural-sounding result highly appreciated by the audio community.
While it is best to protect a delicate ribbon microphone from blasts of sound pressure or phantom force, many modern ribbon mics designs offer an alternative to fragile older ribbons.
Bidirectional Ribbon mics have a figure-8 pattern, which is why they are bidirectional ribbon microphones. The ribbon will not respond to sound coming from the sides to move at all. This polar pattern offers a strategic option for recording.
You can place sound sources you don’t want to capture on the right or left axis of your ribbon microphone. This polar pattern of the ribbon microphone can capture a sound and record the interaction of the sound with space/space behind it.
Other Types Of Microphones
Boundary microphones, also known as PZM microphones, are small condensers. They are typically mounted to a plate and then placed on a surface such as a wall or a floor.
This is useful when you want to avoid interference between sound reflections or direct sound. These mics are used in the recording studio to blend with other microphone signals or for sonic experimentation.
Contact microphones are made from materials that can respond to mechanical vibrations rather than air vibrations. These mics focus almost exclusively on sound traveling through objects or structures.
Piezo microphones are also known because of the way that this electric charge accumulates.
Boundary mics and contact mics are sometimes confused because they are placed on the same surface. However, their signal generation process is completely different.
Although they don’t provide a complete sounding result, they can be combined with other microphones to enhance the recording.
Lavalier (lav), or lapel microphones, are small condenser microphones attached to a clip worn or carried by a performer or speaker. They are a great choice for public speaking, theatre, and tv because of their hands-free design.
Shotgun microphones are also known as interference tube microphones. They are highly directional microphones designed to pick up a particular sound source from a distance while rejecting most noises in the environment.
These microphones are ideal for field recording or any dialogue where a standard microphone or lavalier may not be the best choice.
How Intercoms Work
Intercoms can be used for baby monitoring and desktop gadgets that enable bosses to talk to their secretaries (or vice versa). Two handsets connected by a copper cable are the most basic type of intercom.
Each handset has a loudspeaker and a few push buttons. Depending on the person speaking, the loudspeaker can be used as a microphone (which absorbs sound) or a loudspeaker (which gives out sound) depending on what they are talking about.
Let’s say Annie (the boss) and Bob (her secretary) are in adjoining rooms. Bob needs to notify Annie that it is time for a meeting, so he presses her talk button.
Annie hears the intercom alarm and presses the talk button. Her handset’s loudspeaker now acts as a microphone. She uses a microphone to talk, and the sound energy from her voice is converted into an electric current.
This current travels down the wire to Bob’s intercom. The current flows into Bob’s loudspeaker and is converted back to sound waves so that Bob can hear Annie’s voice. Bob is now ready to speak.
The intercoms are now in reverse when he presses the talk button. Bob’s loudspeaker functions as a microphone and captures his voice, turning it into an electrical energy current that flows down the cable to Annie. Annie’s handset now functions as a loudspeaker, reproducing Bob’s voice.
These intercoms, which are straightforward, are most fascinating from a scientific perspective. They teach us that microphones and loudspeakers are opposites.
There are many other types of intercoms that you may prefer. Many handsets have both loudspeakers and microphones so that two people can speak simultaneously.
Wireless intercoms work more like walkie-talkies (short-range radio sets), and there are no complicated cables that can tangle or get in the way. Others plug into the house electrical outlets to send their voice signals around the wiring rather than wire cables. They operate in a similar way to broadband over powerlines (BPL).
The Microphone Size is Important
A capsule houses the components that produce a signal. Although pills come in various sizes, they are generally standardized to fit two types of condenser mics: large and small diaphragms (roughly 1 inch and 1/2-inch, respectively).
This measurement is for the diaphragm within the capsule. However, some manufacturers use the whole tablet.
Technically, it is essential to note that the diaphragm’s size increases with its weight. This means that the low-frequency response of the diaphragm will improve while the high-frequency signal response of the diaphragm will decrease.
A larger area means more acoustic energy can be captured. This results in a stronger signal and a lower signal-to-noise ratio.
Natural sound quality can also be affected by the microphones used. It can be challenging to recreate vintage mic sounds with modern microphones, either manually or physically.
It’s better to use microphone voice changer software with any recording effect you need than to alter the science behind your set-up.
Large-diaphragm Condensers are the preferred choice for recording vocals or other solo instruments in the recording industry. They are well-known for their stunning sound reproduction, particularly at low frequencies.
They are famous for their transient response and neutrality. These condensers can do wonders for natural, uncolored results. They are frequently used on string instruments and percussion.
Polar Response Patterns for Microphones
Some microphones can have multiple polar patterns, while others only have one.
A small symbol may be found near the microphone’s capsule. These symbols indicate which direction a microphone picks up sound best or its “polar pattern.” Understanding the polar patterns can help you choose the right microphone for your recording situation.
There are two basic polar patterns: omnidirectional or figure-8. An omnidirectional microphone, also known as ‘Omni,’ picks up sounds equal. You can visualize this as a picks-up sound circle around the microphone’s capsule.
Many lavalier models use this polar pattern as it captures the subject’s voice regardless of their orientation. The figure-8 (bidirectional) polar pattern picks up sounds from the front and back. It ignores sounds coming from the sides, as we discovered with ribbon mics.
The combination of the figure-8 and Omni polar patterns allowed for more directional patterns. The cardioid pattern and its variations, super-cardioid or hypercardioid, are the most notable.
This is illustrated by placing the figure-8 design on top of the Omni. The positive half of the figure-8 is doubled with the Omni pattern.
The negative half cancels out. While the sides are the same, you’ll see that the sides stay the same.
Hypercardioid or super-cardioid increases the blend of figure-8 patterns, which results in a narrower directionality at the front, at the expense the rear cancelation cardioid provides.
These patterns will almost certainly suffer from a dampening in high frequencies if they are off-axis.
The cardioid pattern can be handy when you want to capture sound sources with minimal bleed from their surroundings. It is a foundational technique for preventing live sound feedback and a staple in recording studios.
Microphones For Different Applications
It is essential to understand the basics of microphone functionality before you can improve your audio skills. It is always helpful to listen to the source of your sound before making any equipment decisions.
What are its tonal characteristics? Is it loud? Are there any sharp transients produced? What does the space around it sound like? Are there any other sounds (for example, a noise source or a live monitor wedge)?
Make You Own Microphone
What if you don’t have a microphone. You’re in luck! It is possible to use a standard earbud and create your own. You need to plug your earbuds into a microphone socket.
You have now essentially switched the function of your earbuds to act as a microphone instead of a loudspeaker. Your voice should be amplified if you speak into an earbud.
This is a great trick! Give it a shot! It may not work with your computer, even though your audio equipment supports it. Sometimes one earbud can be used as a microphone while the other won’t. It’s up to you to test it.
Try changing the sound settings on your computer if it does not work. Some programs will allow you to do your experiment, while others may not.
What is the working principle of a wired microphone?
A magnetic field creates a current when a wire is moved in the magnetic fields. This induction principle is used to create the dynamic microphone.
Dynamic microphones use a coil of wire, magnet, and a thin diaphragm for recording the audio signal. The dynamic microphone ring is connected to the diaphragm.
What is the function of a microphone?
A microphone converts sound waves to electrical signals. Microphones use the generator effect to create a changing current (or induce sound waves into electrical signals) from sound pressure variations.
How do microphones work in Electronics?
Because it converts energy from sound waves to an electrical signal, microphones can also convert energy. It is also a transducer.
The majority of microphones emit an electrical password, where the changes made to the call corresponding to the changes in the sound wave being received by the microphone.
What is the microphone used for?
Microphones work as a device that converts sound vibrations from the air into electronic signals or records them onto a recording medium. Microphones can be used for many purposes, including communication and the recording of speech.
What are the characteristics and uses of a microphone?
- Extremely high sound levels.
- Sound waves strike the diaphragm
- The diaphragm vibrates as a response.
- The diaphragm and voice coil vibrate together.
- The magnetic field generated by the magnet surrounds the voice coil.
- The electrical signal is generated by the motion of the voice coil within this magnetic field.
Broadcast apps, streaming, youtube are increasingly popular, both onstage and in the studio, microphones are among the most important tools. Learning how microphones work can help you understand the importance to invest in good microphones, to maximize sound system performance potential.
Hope this article of Hooke Audio can help you know how microphones work and choose the right microphone to use for recording studios, broadcast, motion picture video production, and on stages for live sound reinforcement to make the best work.