What Is Microphone Sensitivity & How Does It Work?
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Microphone sensitivity is an important topic when it comes to microphone quality and usage because they have many applications in our daily lives.
As energy can’t be created or destroyed, microphones convert mechanical energy into electrical waves.
We use them to chat, sing, record, perform on and off stage.
Baby monitors also have them.
And so, there are many different types of microphones with different features and different degrees of sensitivity.
Table of Contents
What Is Microphone Sensitivity?
Microphone sensitivity refers to the microphone’s ability to capture a certain amount of the electrical output. It’s calculated in relation to the amount of sound pressure applied to it.
In other words, when the electrical output of the microphone is strong and without distortions, the microphone is more sensitive. This microphone is a much better option for recording than the one with less sensitivity.
The microphone with less sensitivity needs a speaker or a singer to invest more effort so that the microphone can convert it to suitable electrical vibrations.
Types and Designs of Microphones
The type and design of a microphone depend on its usage.
For instance, those we use with mobile phones for our conversations are very small and compact.
However, professional musicians and singers use a completely different type of microphone when they perform in their studios or at concerts.
The microphone world is a big world with no limits.
In this article, we will present different types of microphones and their sensitivity ranges.
Dynamic vs Condenser Microphones
What one considers to be a good microphone depends on the purpose of use, time, place, and the way one uses it.
For example, if you are surrounded by noise (even music!) and want to achieve good sound quality output, the dynamic microphone is the best.
On the other hand, if you are using your microphone in an area without additional sound sources, condenser microphones are a good choice.
So, dynamic microphones are a good option if you want to capture and record loud, strong sounds produced by instruments such as drums, electric guitars, or even loud vocals, especially in a live setting.
Dynamic microphones do not need a power supply to work.
Contrarily, condenser microphones are a much better option if you need to capture delicate and high-frequency sounds.
However, not only they will reproduce vocals accurately and make awesome singers sound even better but will also give a rendition of their faults, which is not a good thing for an average performer.
Nonetheless, both types of microphones are used in studio recordings.
Advice: test and play with the position and distance of your microphone when you are using it because the location of the microphone during recording differs in the quality of the resulting sound.
You will learn more about it later in this article.
Polar Patterns of a Microphone
How a microphone picks sound depends on the direction of the microphone.
One of the myths is that the microphone picks up the sound from its upper part.
However, microphones have different polar patterns, and these, in turn, determine how microphones pick up sound, “hear” sound, and which parts of a microphone are closed or open.
Knowing a little about these patterns will help you choose the microphone that picks up the sound you want while avoiding disturbances or side sounds as much as possible.
Cardioid Microphones
Cardioid Microphones microphones pick up all the sounds in the front while ignoring the background sounds.
Their sensitivity area is heart-shaped; thus its name “cardioid”.
Thus, direct the microphone to the source of the sound you want, for instance, during live recordings when most background sounds are unnecessary.
This type of microphone is the most popular and widely used in live performances.
You can use it during fun times such as karaoke or large parties.
Similarly, it is widely used when recording loud instruments such as guitars and drums.
The position of the microphone is important here, as it distorts background sounds and thus you should adjust it towards the source.
Hypercardioid Microphones
Hypercardioid microphones operate similarly to cardioid ones, but their sensitivity is lower.
Lower sensitivity results in greater isolation and resistance to background sounds, and as a result of the greater resistance of these mics to background noise, they are widely used in loud parties or in untreated recording rooms against noise.
Omnidirectional Microphones
Omnidirectional microphones pick up sound from all directions as a result of their undirected design, but they capture the subtle differences, which results in a more natural and lively sound.
Consequently, these microphones can be used in live and studio recordings, or in places of worship.
One of its obvious drawbacks is that it has no resistance to background sounds, which makes it a poor choice for places with a lot of background noise.
Figure-8 microphones
Figure-8 microphones have a shape similar to number eight (8).
Consequently, they can capture front and background sounds while ignoring side sounds.
They are mono microphones but with noise resistance on the sides, while the front and the back remain sensitive.
These microphones are a good choice for stereo recordings or recording more than two instruments at the same time.
Shotgun Microphones
Also called linear mics, shotgun microphones are directional even more than hyper-cardioid mics.
For that reason, they can capture a range of sounds in addition to a large concentration of frontal sounds.
Multi-Pattern Microphones
Multi-pattern microphones can switch between different polar patterns.
Many modern USB connectivity condenser mics have this feature.
Some have the option to switch between polar patterns simply by pressing a button and, in others, you can do that by changing the microphone head.
The advantage that these microphones provide is clear, and it is getting more possibilities for their placement and more uses.
Just remember, you must be careful in your dealings with this type of microphone because of course, you do not want to harm the parts that distinguish them from others!
Never cover the head of the microphone with your hand, as it will create too much noise!
For example, if the covered microphone is cardioid, it will turn into a mono microphone and will capture sound from the speakers around it, causing a lot of acoustic feedback.
Diaphragm Sizes
Microphones pick up the sound with a specific membrane/diaphragm, which consists of a thin material that vibrates when the sound hits it.
Actually, these vibrations are what convert sound energy into electrical energy.
There is no actual standard for measurement, but there are currently three main types of membranes for microphones, which all refer to the mass of the membrane.
It is the size of the membrane that influences the sensitivity and range of the microphone, and many other factors.
According to the type of membrane/diaphragm, microphones are divided into three categories.
Small Diaphragm Microphones
Small diaphragm microphones are often called pen microphones because of their small cylindrical shape.
Compared to other microphones, their shape makes them lighter and easier to move around during performances.
Thus, they are also firmer and stiffer to withstand higher sound pressure.
The disadvantage of this type of microphone is that it has low sound sensitivity.
Large Diaphragm Microphones
The larger the diaphragm, the greater the microphone’s ability to capture air vibrations.
Likewise, the more vibrations a microphone captures, the better the acoustic detail output.
They can pick up different sound pressures, which results in a clearer, more natural sound.
The properties of these mics make them essential in recording studios.
You can use them to record almost everything!
Just be sure to keep track of the pitch as it can distort the sound.
Medium Diaphragm Microphones
Medium diaphragm microphones are sometimes called hybrid microphones because they combine the characteristics of both small and large-diaphragm microphones.
These mics combine the warm, clear sound of large diaphragms while retaining the high-frequency sounds of small-diaphragm mics.
These are newer devices that have gained a good reputation among professionals.
Nonetheless, this type of microphone is not essential for the best sound output.
It all depends on your needs and the purpose of use.
Three Types of Microphones in Musical Recording
Now we’re going to talk about three popular types of microphones with USB or XLR connectivity used in the music recording industry.
Dynamic Microphones
If you are looking for reliable and versatile mics, you should start with dynamic mics.
These microphones contain membranes with magnetic coils that guarantee to pick up sounds under high sound pressures.
You can use them to record loud sounds such as electric guitars or drums without worrying about distortion or damage to the quality of the sound.
Condenser Microphones
Condenser microphones contain a thin and conductive membrane located under the iron part, which acts as a capacitor.
So it converts the vibrations of the air that collide with it into acoustic signals.
For that reason, this type of microphone differs from others, as the membrane acts as a capacitor, which results in a significant improvement in the accuracy and quality of the sound produced.
Consequently, these types of microphones are suitable for recording studios.
They usually need an electronic mixer (mixer) or a phantom power supply.
Whatever type of music you’re trying to record, condenser mics will do the job perfectly as long as the sound pressure isn’t too high.
Ribbon Microphones
Nowadays, these mics are not as popular as other types.
However, they were essential a long time ago for radio recording.
The thin metal strip used in these microphones allows them to capture not only the displacement but also the speed of air, which causes greater sensitivity to high frequencies and good capture of loud tones.
Interest in this type of microphones has returned these days, especially because new versions have become more stable and more reliable compared to their old counterparts.
They are useful for multi-instrument recording in places with a reasonable noise level.
Likewise, you can also use them if you are looking for that old acoustic touch in your music or alongside dynamic condenser mics for more dynamic music.
Wired and Wireless Microphones
Views differ when you compare wired and wireless microphones.
Some users insist that wireless microphones are better, while others claim the opposite.
What is the truth?
In fact, comparing the two types is like comparing Android and iPhone phones.
In the end, both have advantages and different characteristics, and your preferences determine which one is better for you.
Wireless microphones contain transducers, which convert sound energy into electrical energy in a similar way as wired microphones.
You can, for example, buy a wired or wireless microphone with a Shure SM58 transducer, even if it is a bit old, but the difference will be in the signal path from the transducer to the next.
With wired microphones, you have a large variety of “pre-amplifiers” that can be both cheap and extremely expensive.
They cost from a few to thousands of dollars.
Their job is to convert the signal from the microphone level (very low) to the output level.
In the case of wireless microphones, it must have a piece pre-integrated with the microphone, so your choices are very limited.
Other than that, wireless microphones can transmit the signal to varying distances depending on the technology used in the broadcast.
If the signals are analog, they may be susceptible to interference that distorts the sound.
However, converting the digital signal might result in an unwanted delay.
Therefore, again, only your personal preferences and needs will determine which type of microphone would work best for you.
iPhone Microphone
When a cell phone’s microphone stops working, the phone usually becomes useless.
Unless you have a great camera and continue using it for photography!
All jokes aside, if your phone’s mic stops working, you won’t be able to make calls or send voice messages through communication applications.
If the mic malfunctions, it could be a minor issue.
Let’s see how to test a microphone on an iPhone.
How to Test your iPhone’s Microphone
The first step in solving the problem of the iPhone’s microphone is to test it until you can determine the origin of the problem.
And here we note that the latest phones such as the iPhone 11, 11 Pro, 11 Pro Max, as well as the X, XS, and XR, all the way to iPhone 8 comes with three microphones.
And these microphones are divided into one microphone at the top, one on the back, and the last one at the bottom of the phone.
To test each microphone separately, you will need to:
- Turn on the front camera for a quick video recording to test the front microphone
- Record a video with the back camera, but make sure that the sound source is in front of the camera and not behind it
- To test the bottom microphone, create a Voice Memo or send a voice message via WhatsApp
This step will help determine which microphone is affected by a problem if there is one.
The first option is the best – all microphones are working perfectly.
The second option implies distortion of a sound.
The third and worst option means that none of the three microphones are picking up sound.
When Your iPhone Microphone Doesn’t Work?
There is more than one way to solve the problem with your iPhone’s microphone.
Let’s try the following.
1. Clean the microphone with a toothbrush
The first thing that you can try is to clean the microphone with a toothbrush to remove dust and fine particles that usually accumulate in the microphone.
You can also use an air compressor, but be careful of the air path.
The toothbrush remains the best tool and presents the least danger to your device!
2. Do not forget to disconnect your phone from the headphones
Perhaps you have forgotten to disconnect your headphones?
Check it out!
Sometimes, we forget our phones are connected to Bluetooth headphones, whether AirPods or others.
If that is the case, the solution is quite simple.
3. Make sure nothing is covering the microphone
Most of us use external protective covers for our phones but they may be poorly manufactured.
Make sure that the protective cover for the phone does not cover the microphone.
Final Thoughts
Incorrectly configured microphone sensitivity settings can cause unwanted background noise or active sound when using the microphone.
This can often cause bothersome or distressing situations when trying to record high-quality audio.
One of the most important criteria for choosing a suitable microphone is its “polar pattern” or directionality.
Directionality refers to the sensitivity of the microphone to sound according to the direction or angle from which the sound is produced.
To determine the microphone directionality, you need to know how the microphone hears a sound from different angles and directions.
So now you know all the basics about microphone polar patterns and their sensitivity, and it’s time to put that knowledge to work.
And while all of this information may be simple in theory, the only way to differentiate the polar patterns of a microphone is to experiment.
Take some time to record different instruments in different rooms, and hear the difference between them.
In time, you will know how to place your microphone and produce the best recording.