How does a dynamic microphone work? Dynamic microphones are one of the most popular types of microphones used today. They are versatile and can be used for a variety of purposes, from recording music to broadcasting speeches.
Dynamic microphones use a moving coil to generate an electrical signal. The coil is attached to a diaphragm, which vibrates when sound waves hit it. This vibration is converted into an electrical signal, which is then amplified and sent to a speaker.
What Is A Dynamic Microphone?
As we have already mentioned, the primary characteristic of a dynamic mic is its ability to work on electromagnetic induction. A dynamic microphone must therefore have the following features:
- A magnetic structure that creates a magnetic field.
- An element conductive that can carry an electric potential difference (voltage).
- The mechanism that allows relative movement of the conductive element with the magnetic field
This is the most basic definition of a dynamic mic. There is more to dynamic microphones than this.
The Two Basic Dynamic Mic Designs
Two types of microphone transducer designs use electromagnetism for audio conversion. They are also known as:
- Moving-coil dynamic microphone
- Ribbon dynamic microphone
We will soon get into the details of each microphone type, but for now, we’ll touch on the basic transducer design.
The Moving-Coil Dynamic Transducer Design
We always assume that a dynamic microphone is a moving-coil dynamic microphone when we hear it. Although ribbon microphones can also be dynamic, they are often called “ribbon mics.”
The transducer’s moving-coil dynamic is equipped with a non-conductive diaphragm and a conductive metal coil (typically copper) attached at its rear.
The coil is housed within the cylindrical cutaway of the magnetic structure. This structure creates a permanent magnetic field that allows electromagnetic induction to occur.
The conductive coil moves with the diaphragm. Through electromagnetic induction, the coil produces an AC voltage due to the oscillation of its conductive coil within its permanent magnetic field. Lead wires transmit this AC voltage via the mic’s audio signal.
The Ribbon Dynamic Transducer Design
The dynamic ribbon transducer uses a diaphragm that looks like a ribbon (typically made of thin corrugated aluminum) and magnetic structures around its perimeter.
The permanent magnetic field produces an AC voltage (mic-signal) as the conductive diaphragm is moved back and forth between its resting position and the conductive diaphragm.
Components of Dynamic Microphones
Dynamic microphones are made up of components that are unique to them.
Seven parts make up a dynamic microphone.
- Grille or Windscreen Windscreen (or Grille) is the portion of the microphone where you can speak or sing.
- Diaphragm. The diaphragm is responsible for converting sounds into electrical currents. It can be compared to the human eardrum.
- Coil. A coil is a small piece of wire that attaches to the diaphragm. The coil is a small section of wire attached to the diaphragm. When it moves, the coil shifts, creating an electrical signal.
- Magnetic Core. It creates a magnetic field that attracts the coil.
- Capsule. Sound vibrations are converted into electrical signals in the capsule. These are then sent to the speakers.
- Body. The device’s body is its external housing. The device’s electronics will respond more effectively to inevitable drops, knocks, and falls if the body is stronger.
- Output. This is where the cable is connected to the microphone for signals to be transmitted as sounds.
Typical Vocal Dynamic Microphone
A dynamic microphone uses sound waves to hit a thin metallic diaphragm attached to a coil wire. In response to it, the coil vibrates by the diaphragm.
Magnetic fields are created when a magnet is placed inside the coil. The motion of the coil creates the magnetic field within the coil. This creates an electrical signal via an electromagnetic induction that corresponds to the sound being picked up.
A current is created by the motion of the microphone’s diaphragm. The speed at which the motion occurs determines the amount of current. Dynamic mics are velocity-sensitive.
The Inner Workings Of A Dynamic Mic
Because it can be used in many recording situations, the dynamic mic is the most popular.
A dynamic mic produces a sound that can be described as mellow and well-rounded.
Nearly all dynamic microphones feature a cardioid pattern of polar response. A cardioid pattern helps filter out noise from the rear of the microphone, thereby allowing for the recording of the source sound.
The key advantages of a dynamic microphone are:
- It is robust and can withstand high sound pressure levels like those generated by a kick drum.
- The good sound quality in all areas related to microphone performance
- They don’t require power to operate
- They are very affordable
There are two main disadvantages to using a dynamic mic.
The microphone’s frequency response is limited by the limitations of heavy microphone diaphragms and wire coils.
A condenser microphone is generally not as good for recording instruments with higher frequencies or harmonics like a violin.
How Does A Dynamic Microphone Work?
The microphone’s capsule contains a diaphragm attached to a coil (or voice coil) of wire suspended in a magnetic field.
The coil cuts through the magnetic flux produced by the poles and moves when a sound wave hits it. This creates an electrical signal in a coil, then sent out from the microphone to a preamplifier.
The electromagnetic induction theory explains this. When a metal material moves through a magnetic field, an electrical current is created.
The proximity effect
On-axis & Off-axis
Sensitivity/SPL / Noise
In volts, a microphone’s sensitivity is measured. This is the amount of signal the microphone will need to be amplified by the mic’s preamp to reach ‘line-level.’ This signal can be used to record other equipment in your studio.When you record in your home studio, the sensitivity of a microphone is not something you should be concerned about. Professional microphones all have high-quality sensitivity ratings.
Dynamic mics can handle extremely high sound pressure levels (SPLs). Some mics can take up to 140dB before distorting. This is close to the threshold for pain.
Another reason dynamic mics excel at recording amps is that they are incredibly versatile. Without worrying about distortion, you can crank the volume up to record the maximum phantom power of an amp.
Because of their physical design, the dynamic model generates more background noise than the condenser microphone. This is called the signal-to-noise ratio, which is why its models are not the best microphone choice for gentler instruments. These situations are better for condensers because they have lower noise backgrounds.
A few times in the past, I tried to record an acoustic guitarist with a dynamic microphone, but the results were useless due to the background noise. If you can, try to avoid it!
Why Use A Dynamic Microphone?
Dynamics have many uses, but these are the most popular. Dynamic mics can be used for vocals with a solid lower-midrange character, ideal for particular songs.
Mics such as the E-V RE20 have become so popular in broadcast studios. Their natural isolation means that any noises, like keyboard clicks or creaking chairs, are not recorded into the audio.
The same isolation can also be a lifesaver for performers on stage. The focused sound of dynamics is ideal for cutting out reflections from the room.
The acoustic guitar is one of many applications for which engineers use dynamics. The mic can pick up the instrument’s sounds but not the fingers of the guitarist sliding along the strings.
Dynamics are better at handling high sound pressure than condensers. They’re therefore a good choice for loud sources like snare drums and cranked guitar cabinets.
Some related articles:
What is a dynamic microphone?
Is a dynamic mic good?
How does a dynamic microphone make physics work?
When would you use dynamic microphones?
Are dynamic microphones powered?
After reading the article, Hooke Audio hopes you will have gained more interesting knowledge about the dynamic microphone that we often use. Dynamic mic work will be interesting knowledge for you.
With a sturdy design, a sound that will make your voice sound warm and inviting, and adept handling of pesky plosives, they’re a great choice for your work or hobby.