While browsing for microphones you must have come across different types of microphones. The most prevalent of them are Dynamic and Condenser. Design, functionality and the applications of both these microphones are very different. Hence, it warrants an explanation. The aim of this article is to help you understand each and everything about dynamic microphones. So, without further ado, let’s answer what is a dynamic microphone?
A microphone’s job is to convert mechanical energy into electrical one. And there are different ways to do this conversion. Dynamic mics do so by using a moving electrically conductive diaphragm and a permanent magnet. It essentially follows the law of electromagnetic induction.
To read about different kinds of microphones and how they differ in their application head to types of microphones. Besides that, there are several other interesting subjects that you read at microphonesgeek.com as of now, let’s get back to the dynamic mics.
Design of Dynamic Microphone- What Is a Dynamic Mic
Dynamic mics have a fairly simple design that works on the principle of electromagnetic induction. It comprises a magnetic structure to produce a magnetic field, a conductive element and a mechanism that enables relative movement of both structures. The conductive element has wires attached to it to carry the voltages in the circuit.
When the mic is subjected to the sound, waves are projected as the diagram holds a moving coil beneath it. The waves of the sound compel the coil to vibrate back and forth which creates an electrical current. It is then carried to the circuit via cables that are attached with the conductive element.
It is basically dynamic mic definition. Every microphone that follows the same design and principle will be known as Dynamic mic.
Before moving further, we must know:
What Is Electromagnetic Induction?
Electromagnetic induction is a phenomenon that produces electrical energy when a stationary magnetic field is subjected to a mobile conductor. It was first discovered in 1831 by Michael Faraday. Since then, the phenomenon has been used in several electronics and microphones are one of them.
Dynamic microphones employ this principle by using a stationary magnetic field and a conductor that can move around. The degree of movement depends on the pressure from sound waves which subsequently determines the magnitude of current. The louder a source, the higher magnitude of current.
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Types Of Dynamic Microphones
The fundamental designs of all dynamic mics are the same but certain differences in the structure create different types. The most popular of them are:
- Moving Coil Dynamic Microphone
- Ribbon Dynamic Microphone
Several other components like windscreen, output and diaphragm are also present in the dynamic mics. But we have not made it the part of our discussion as they are not exclusive to dynamic mics.
1.Moving Coil Dynamic Microphone
In the moving coil dynamic mics, the transducer is non-conductor with a metallic coil attached to it. It essentially means that the diaphragm itself cannot conduct but the coil beneath it can carry electric current.
The magnetic structure has a cylindrical shape which is where the coil sits. It provides a magnetic field that is necessary for the electromagnetic induction. As the diaphragm comes under pressure of sound waves it causes coils to move which results in induction of electric current.
One must be mindful about the fact that the coil sits within the magnetic structure but it can oscillate. It is sandwiched between the two poles of a magnet which generates a proper magnetic field.
As the coil moves it generates electric current and the cables attached with circuit take it forward. The cables terminate at the output of the mic which is where the job of receiver starts. At the terminal point, there is a transformer which amplifies the voltages and protects the mic from DC voltages.
2. Ribbon Dynamic Transducer Design
As mentioned earlier all the dynamic mics feature the same fundamental design but there are some subtle differences. In contrast to moving coil mics, ribbon dynamics have a conductive diaphragm. This ribbon-like diaphragm typically uses ultra-thin aluminum as construction material. And a magnetic structure surrounds it.
Like the moving coil, as the ribbon-like structure moves it produces electrical current. And it again, follows the same path as moving coil mics and ends up at the output.
The Characteristics of Dynamic Microphone
Although all the dynamic mics may not exhibit these characters, these are true in most cases.
Dynamic microphones are more durable and rugged than their condenser counterparts. It is because their circuitry is tough and resist the damage caused by DC current. Condenser Microphone on other hand have delicate circuitry. To know more about them, follow our comprehensive guide about the condenser microphones.
Not So Sensitive
The robust circuitry comes with its fair share of shortcomings and one of them is sensitivity. In order to generate the current coil has to move and it only moves when it comes under a pressure over a certain threshold. It limits the microphone’s ability to capture faint sounds like low notes on vocals.
This is in contrast to the condenser mics which are highly sensitive and ideal for vocal recording.
High Max SPL
Max SPL is the ability of a microphone to record the loud sounds without distortion. Higher the SPL, the better capability of the microphone to capture loud sounds. By virtue of their robust design, MAX SPL of the dynamic microphone is quite high which makes them ideal for the loud sounds.
Again, it is in contrast to the condenser mics which are not that great when it comes to recording loud sounds.
In simple terms, it means how a microphone responds to the different sound frequencies. It defines a range of frequencies that a particular microphone can replicate. Dynamic mics perform much better at higher frequencies than the lower ones.
When the mic is close to the sound source you would experience a boost in bass frequency. It is what sound engineers call the proximity effect. It usually happens when the distance between mic and source is about one foot. As the source moves farther the proximity effect begins to disappear and echo kicks in.
Do Not Require Phantom Power
Phantom Power is a necessity for the most condenser mics but most dynamic mics do not need it. This is what makes them easy to use.
As discussed earlier, dynamic mics have a very simple design which makes them inexpensive to build. Therefore, you would find that these mics come at much cheaper prices than their condenser counterparts.
Furthermore, since phantom power is not required no interface or external preamp is needed. It cuts the operating cost even further.
Application Of The Dynamic Mics
As you know the characteristics of dynamic mics, it is quite easy to predict their application. Some of them are as follow
Dynamic mics are ideal for capturing the ambient environment which make them ideal for live performances. In fact, these are the standard mic for the live vocals and instruments. The ruggedness of the design helps them cope with the rougher on-stage performances.
Furthermore, the polar pattern, low sensitivity and frequency response enables them to gain high gain-before-feedback. Something called presence boost which is peculiar to dynamic mics makes the audio clearer on the stage.
Use of dynamic mics in the studio is quite limited but in some cases these mics can come in handy. For example, while recording loud musical instruments such as drums or electric guitars. The condenser mic would be able to perform effectively given that their SPLs are low.
Furthermore, music genres that involve loud screaming vocals can also employ dynamic microphones. It will deliver a very lively sound quality.
Limitations Of The Dynamic Mics
Dynamic mics have some limitations as well which you must be aware of while getting yourself a dynamic microphone.
Not For In-studio Vocal Recording
These mics have robust structure which makes them very less sensitive and not suitable for indoor vocal recordings. Plus, they are not well equipped to deal with faint sounds so it cannot effectively capture the low notes.
Less Detailed Sound
Since dynamic mics are not as sensitive, they cannot capture a wide range of frequencies. It makes their sound less detailed and not suitable for recording delicate sounds.
Conclusion- What Is A Dynamic Mic?
Dynamic mics are the oldest form of the recording devices that employ the principle of electromagnetic induction. These are the most rugged mics and ideal for capturing ambient sound in live performance. Thanks to their simple design, they come at much cheaper cost and are affordable for all. They do have some limitations like low sensitivity and narrower frequency response. But all in all, they still remain an effective and useful part of the audio gear.
This is all that we had on “what is a dynamic mic”. We hope this article has cleared your confusion around the subject. If you have any query let us know in the given section. We would love to respond.