How Does A Dynamic Microphone Work? Top Full Guide 2021

How Does A Dynamic Microphone Work Top Full Guide 2021

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

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.

Typical vocal dynamic microphone

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.

Advantages

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

Disadvantages

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.

dynamic microphone work
The voice coil moves through the magnetic field of the magnet when the diaphragm is moved. An electrical signal is then produced that corresponds to the recorded sound. It is the way dynamic microphones work.

Frequency Response

These mics are solid and long-lasting. These mics can record loud sounds, such as guitar amps and drums. These instruments are not suited for dynamic mics because they don’t have high-end frequency detail.
The frequency response of Dynamics is usually slightly higher in the mid-range, which means that specific frequencies are emphasized a bit more than others. This feature of microphones makes them useful for amps that already emphasize these frequencies. The frequency bump usually lies between 1kHz and 8kHz.
Some of the most iconic dynamics, such as the SM57 and SM58 from Shure, have distinctive sounds due to their specific mid-range frequency response.
This microphone’s high-frequency response is around 15kHz. They are not suitable for recording instruments that are better suited for condenser microphones. A dynamic microphone is best to register with more detail but still have a rich sound.

Other Factors

The proximity effect

The proximity effect can also affect mics, just like condenser microphones. The proximity effect is something you should be aware of. The proximity effect causes bass frequencies to rise when sound sources are too close to the microphone. This is usually around one foot.
Although you can filter out lower frequencies at the mixing stage in the future, the proximity effect is best to record the audio at its source.

On-axis & Off-axis

Recording with a microphone requires that you consider both the on-axis and off-axis responses.
The mic’s on-axis response describes how the microphone records sound coming in from the front. This is how the mic should be used. Any sound that enters the microphone from any direction, whether from instruments or sound reflections in the room, is called the off-axis reaction. You could do this by entering the microphone’s back.
You want to record the on-axis response. The off-axis response should not be underestimated in smaller studios, where the sound quality is less than ideal.

Polar Pattern

Because dynamic mics are designed and built to be versatile, they come standard with the cardioid pattern. This polar pattern is best for smaller studios as the polar pattern is not difficult to use.
Cardioid responses are directional, so a polar pattern is best to record the sound on the microphone’s axis. If you use the close-mic technique, any sounds or reflections from the room will be minimized.

Transients

A microphone’s transient refers to the speed at which it reacts to an incoming sound. Much information can be found in the first 100-100 milliseconds after a sound is received in the studio. Think about the first crack of a drum snare. The transient response is the speed at which the microphone reacts and captures this initial sound.
Dynamic reacts slower than condenser microphones because of the large moving-coil dynamic microphones and inner diaphragm. They can also struggle to capture sharp and fast transients due to their slow reaction. This is why its sound has a rugged, low-end frequency response.
This is not a bad thing. A dynamic microphone can be used to record guitar amps, bass amps, drums, and vocals.
How does a dynamic microphone work

Sensitivity/SPL / Noise

Sensitivity
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.

SPL

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.

Noise

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

Dynamic mics have seven parts that, together, create their one-of-a-kind sound.
  • 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.

Types of Dynamic Microphones

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.

FAQs

What is a dynamic microphone?

With the help of a magnet, dynamic microphones convert sound waves into voltage. They work in the reverse order of speakers. A speaker vibrates electricity through the diaphragm to create it. These microphones, on the other side, use sound waves to vibrate the diaphragm creating electricity.

Is a dynamic mic good?

Dynamic microphones are great for recording vocals, whether you’re podcasting or voiceovers. They also work well when recording multiple people at once. … For dynamic mics to be effective, particularly higher-end models, they require high levels of gain.
dynamic mic good

How does a dynamic microphone make physics work?

 When dynamic microphones work, they use sound pressure variations to move the cone. This forces the attached coil of steel in a magnetic field which generates voltage. … The audio signal causes the ring to move in response, moving the cone and creating sound in the air.

When would you use dynamic microphones?

Many instruments have a lot of low-mid energy. It can be used to compensate. To compensate, they have a presence boost for the high mids. Many dynamics have a roll-off in the bass, so they are not ideal for low-end instruments like the kick and bass.

Are dynamic microphones powered?

Although dynamic microphones don’t require power supplies, a majority can work without phantom power. However, there are exceptions. All condenser mics require some form of power supply. The power supply is also needed for active dynamic microphones.

Conclusion

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.

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