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?
- The Two Basic Dynamic Mic Designs
- Components of Dynamic Microphones
- How Does A Dynamic Microphone Work?
- Why Use A Dynamic Microphone?
- Features of the Dynamic Microphone
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.
- 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.
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.
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.
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Features of the Dynamic Microphone
Here are some of the key features of dynamic microphones:
- Durability: Dynamic microphones are very rugged and can handle high sound pressure levels without distortion, making them ideal for capturing loud sound sources such as drums, guitar amps, and vocals.
- High output level: Dynamic microphones have a high output level, which means they can produce a strong signal even when used with a low-gain preamp or mixer.
- Directionality: Dynamic microphones are typically unidirectional or cardioid, which means they pick up sound primarily from one direction while rejecting sound from other directions. This makes them ideal for live sound reinforcement and recording applications where unwanted background noise must be minimized.
- Low self-noise: Dynamic microphones have very low self-noise, producing very little noise when no sound is present. This is particularly useful for recording applications where low noise is essential.
- No external power required: Dynamic microphones do not require external power, making them a popular choice for stage use and applications where portability is important.
- Wide frequency response: Dynamic microphones can capture a wide range of frequencies, making them suitable for various sound sources.
- Affordable: Dynamic microphones are generally more affordable than condenser microphones, which makes them a popular choice for beginners and those on a tight budget.
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How does the diaphragm of a dynamic microphone work?
The diaphragm of a dynamic microphone is a thin membrane that vibrates in response to sound waves. The movement of the diaphragm is then translated into an electrical signal by the coil of wire attached to it.
Can dynamic microphones pick up low-level sounds?
Dynamic microphones are generally less sensitive than condenser microphones, so they may not be the best choice for recording very low-level sounds.
However, they can still capture a wide range of frequencies and are often used for live sound reinforcement, where they can handle high sound pressure levels without distortion.
How do you connect a dynamic microphone to a sound system?
To connect a dynamic microphone to a sound system, you will need a cable with an XLR connector on one end (which plugs into the microphone) and a 1/4-inch or XLR connector on the other end (which plugs into the mixer or amplifier).
Check the microphone and sound system manual to ensure you use the correct cable and settings.
How do you care for a dynamic microphone?
To keep your dynamic microphone in good working order, store it in a dry, cool place when not in use and avoid exposing it to extreme temperatures or moisture. You should also clean the grill and diaphragm periodically with a soft brush or cloth to remove any dust or debris.
Can dynamic microphones be used for recording vocals?
Yes, dynamic microphones can be used for recording vocals, although they may provide a different level of detail and clarity than condenser microphones. However, they are often preferred for live performances and recording loud sound sources such as drums and guitar amps.
Dynamic microphones are a great choice for many sound reinforcement and recording applications. By understanding how they work, you can make an informed decision when choosing the best microphone for your needs. To learn more about dynamic microphones and other microphones, check out our complete guide to microphones today!