Dynamic microphones turn sound waves into a voltage with the use of a magnet. They work like speakers but in reverse.
It is the most used type of microphone, with relatively high efficiency, suitable for many different purposes. But not many people know how does a dynamic microphone works?
Isn’t it great to discover how one of the popular mics works? This is the article for you if you are curious about that.
Typical vocal Dynamic microphone
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
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!
Components of Dynamic Microphones
- Windscreen (or Grille): The windscreen is the part of the microphone that you speak or sing into.
- Diaphragm: The diaphragm collects sounds and transforms them into electrical currents. It can be equated to the human eardrum.
- Coil: The coil is a small section of wire attached to the diaphragm. When the diaphragm moves, it shifts the coil, which creates an electrical signal via electromagnetic induction.
- Magnetic Core: It produces a magnetic field for the coil.
- Capsule: In the capsule, sound vibrations are converted to electrical signals, which are sent to the speakers.
- Body: The body is the external housing of the device. The sturdier the body, the more easily its electronics will be able to handle inevitable falls, knocks, and drops.
- Output: The output (or output jack) is where a cable is plugged into the microphone so that signals can be transported out as sounds.
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.
Types of Dynamic Microphones
There are two types of dynamics: ribbon microphones or moving-coil microphones. However, some people are unaware that ribbon microphones can also be used as dynamic mics. Even so, ribbon microphones typically have lower sensitivity than a moving coil dynamic microphone.
The small-diaphragm and large-diaphragm types of moving-coil dynamic microphones are divided. While there is less differentiation between dynamic mics and condenser mics in diaphragm size, the sonic impact can be profound.
The target frequency is usually lowered the more significant the diaphragm. Large-diaphragm dynamic microphones such as the Sennheiser MD 421II and the AKG D112 MKII are great for toms, kick drums and deep male vocals.
This is evident in the DW Moon Mic, which has a microphone diaphragm built on a speaker cone and a target frequency that is very low for bass drums. Other dynamics such as the Blue Microphones enCORE100 and the Audix i5 fall into this category and can be used for various purposes.
You’ll need to have enough dynamic microphones for both sound reinforcement and tracking. Sweetwater Sales Engineers are happy to assist you in finding suitable microphones to suit your needs.
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.