All microphones implement the same basic internals, which is a transducer that converts sound energy into electric energy. One of the main ways to differentiate microphones is that some have cables while others are wireless.
Wired microphones have their time and place, yet in certain use cases, they are not ideal. For instance, they invite all kinds of accidents if used on stage. If the wires are all over the ground, there is a risk that the performer can trip over the wires and injure him or herself.
To avoid problems like those and to improve usability in many situations, wireless microphones were invented in 1957. They have become the best way to transmit sound or speech in public places. The widespread availability of wireless microphones has made it so that there are many affordable options for those on a budget.
In this article, we discuss how wireless microphones work and features to look out for when shopping for one so that you can make an informed choice when you go out to buy one.
Difference Between Wired and Wireless Microphones
Cabled microphones convert sound waves into electric signals directly. The signal goes into the sound system, and it comes out as audio.
Wireless or cordless microphones divide this process into two parts. The microphone that you see upfront contains only a transmitter that operates by battery.
The transmitter transmits the audio signals into the receiver through radio signals. The receiver converts the radio frequency waves into an audio signal that feeds into the sound system in audio form.
To summarize, you could say that the cordless microphone and the transmitter do the work of a radio station, and the receiver does the job of radio. You can tune the radio to match the exact frequency of the transmitter!
Advantages of Wireless Microphones
- They free movement because you don’t need your other hand to adjust the cable.
- No chances of mishaps or problems of tangling of cables while performing on stage.
- Clean and pleasing appearance
- Many wireless microphones are available on the market by different brands so that you can pick and choose based on your needs.
Where Are Wireless Microphones Used?
- Public meetings
- Political leader
- Film and video production
- Meetings by business people.
Components of Wireless Microphones
The wireless microphone consists of mainly three components. The components are the microphone, transmitter, and receiver. We will discuss the components one by one in detail.
Cordless microphones are also transducers like their wired counterparts and are available in various transducer principles like moving coil, condenser, or ribbon dynamic. The sound waves vibrate the microphone’s diaphragm, which then converts the acoustic energy into an electric signal. Sometimes the signal is even amplified within the body of the microphone before its output. But the body of the wireless microphone differs from the wired microphone.
The wireless microphone is available in three types.
#1a. Handheld wireless microphone
The handheld microphone provides you the best sound quality in comparison to other wireless microphones. You will find a transmitter inside the handle of the wireless microphone.
However, they require batteries to perform cordlessly, so they are a bit heavy in comparison to the wired handheld microphone. These mics are an excellent option for giving presentations or delivering a speech on stage. They are an old-fashioned mic, but they are sturdy and durable. With a handheld wireless mic, you do not need to use both of your hands while delivering a speech on stage.
#1b. Lavalier Or Clip On Microphone
If you do not want to use your hands during your performance, I suggest you purchase a lavalier or clip-on microphone. You will find numerous mounting options here. For instance, you can fasten them on the collars of your shirt, ties, or any other portion of your clothing. They are quite comfortable to use.
The caveat is that the smaller size here means that the quality of the audio is not that good in comparison to the handheld cordless microphone. Clip-on microphones link to the transmitter, which then sends the radio signal to the receiver.
The lavalier or clip-on microphones have a thin cable that connects to the transmitter. These transmitters are mainly attached to the belts to the user. Therefore, they do not qualify as wireless mics. You can also connect a wireless mic to a PC or Mac.
Lavalier microphones can be directional or omnidirectional. Omnidirectional wireless lavaliers can pick up sound in any direction.
That is not any problem when the mic is close to the sound source. Still, if you keep the lavalier microphone away from the sound source, it can pick up so much additional sound, which may hamper your presentation or deliver a speech on stage.
These microphones are ideal for shooting videos or speaking in front of a public audience.
#1c. Countryman Microphone
These microphones are lightweight and consist of high-quality materials. They are small but more advanced than the lavalier microphone. You can quickly fix these microphones on your hair as well as your skin. The capsule in these microphones is resistant to sweat or moisture.
Most countryman microphones have omnidirectional polar patterns, i.e., it picks up sound from all the angles.
These microphones are ideal for theatres, public speaking, television, and interviews.
#1d. Fitness Headset
If you spend most of your time on physical activities and need a microphone that can handle your fitness, purchase a fitness headset. The fabric in these microphones repels moisture, i.e., they are hydrophobic. So, indirectly, it protects the cartridge from corrosion which may occur in a location where it is more humid.
They are ideal for aerobic instructors or fitness instructors.
#1e. Headset Microphone
Headset microphones are worn over the head. It is lightweight and allows you complete freedom to move your hands or to move independently. However, it includes a bodypack transmitter and a wireless receiver along with it.
The transmitter is a component of the microphone that transfers the audio signal to the receiver. There are three types of transmitter. Let’s discuss them one by one in detail.
#2a. Handheld microphone transmitter
The handheld microphone transmitter is present inside the body of the microphone. It operates with the help of a small battery. The handheld transmitter’s job is to convert the sound waves into radio waves, and then they are broadcast from the antenna, which is present at the base of the microphone.
#2b. Belt Pack Transmitter
If you use a lavalier microphone or headset microphone, you need to use a belt-pack transmitter. It is a small box shape that usually attaches to the belt, or you can keep it inside the pocket. The shape of the box is similar to a cigarette packet.
#2c. Plug-In Transmitter
Plug-in transmitters are a type of transmitter box in which you can plug your regular microphone. It can transform wired microphones into wireless.
The transmitter does the work of converting the audio signal into radio waves. These waves are transferred to the receiver, transforming into an audio signal that you usually hear from the sound system.
The receiver has mainly two antennas so that it can pick up the signal correctly from the transmitter.
There are three types of receivers, and each receiver has a different method to receive the signal.
#3a. Non Diversity receiver
The non-diversity receiver has one antenna to receive the signal from the transmitter. As it has one antenna, its performance is not that good in comparison to another receiver. Sometimes there is a total loss of the audio signal in this receiver.
#3b. Diversity Receiver
Two antennas are present in these receivers to capture the signal from the transmitter. If one antenna has issues or weakly receives the signal, then the receiver uses the other antenna to receive the signal.
This receiver can strengthen any weak signal that is transmitted by the transmitter. But it may also sometimes weaken the strong signal.
#3c. True Diversity Receiver
In two diversity receivers, you will notice two antennas separated at a distance of two inches from each other. These antennas are placed at an angle of 45 degrees.
The receiver receives a signal from both antennas but chooses the most robust signal to convert into an audio signal.
What is Wireless Microphone Frequency?
We measure frequency in terms of Hertz. The human ear can register frequencies ranging from 20Hz to 20,000Hz.
The wireless mics transmit the sound in terms of operating frequency. We also call this operating frequency radio frequency. There are three types of this operating frequency.
#1. Frequency Modulation
Most wireless microphones use frequency modulation for the transmission of a signal to the receiver by radio waves. But to do so, they need to achieve a maximum of 200 kHz bandwidth. Now, what is bandwidth? Bandwidth is the difference between the upper and lower frequencies in a continuous band or cycle. To access 200 Khz bandwidth, radio frequencies consist of two types.
- VHF(very high frequency ), which is in between 30 to300MHz
- UHF(Ultra high frequency), which is in between 300Mhz to 3GHz
Very High Frequency
The wireless microphone system setup is quite simple in VHF wireless microphones. It is simple because they operate in just one frequency. But there is a lot of disturbance because another wireless device may share the frequency.
Here you always have an option to change the frequency. So, this makes it possible to use multiple radio mics at one time.
We call the 300MHz to 3GHz frequencies a television band. The television band in Europe is 470 to 614MHz.
Remember that the transmitter and receiver should operate at the same frequency to send the signal properly from transmitter to receiver. You can think of your transmitter as a radio station that sends the audio from the microphone. A disturbance may happen if there are other transmitters and they will be sending the signals with the same radio frequency, which is called radio frequency interference. You can quickly solve this problem by using good quality wireless systems that quickly change the transmitted frequency.
#2. Fixed Frequency
These devices have a fixed frequency which you cannot modify. That’s why you can use these devices only in a particular area.
#3. Frequency Agile
The frequency-agile system is an advanced system that captures the best frequency for you.
How to Choose a Wireless Microphone
The range or distance covered by a microphone usually differs from one microphone to another. Some may have a very short range, while others may have a 1000 feet range.
The size of wireless microphones vary quite a bit, and you ought to choose a size that fits your use and preferences. If you want to hold onto your mic while delivering a speech or presentation, you can invest in a handheld microphone. Some people don’t like to touch the microphone while giving a speech, so lavalier mics could be better for these folks.
#3. Battery Life
Wireless microphones mainly use AA batteries. Alkaline batteries are the best non-rechargeable batteries because they are durable.
Some microphones use rechargeable batteries, which are convenient because you don’t need to buy separate batteries or swap batteries ever. Most rechargeable batteries last for five hours.
Latency means the time taken by the wireless microphone to convert a signal into audible sound. Latency within 15ms is good if you are using a wireless microphone in conferences. If the latency is high, then it becomes a problem for the presenter.
The wireless microphones convert analog to a digital signal and then again into an analog signal which happens in just a few seconds. But this also adds some latency to the microphone. If you invest in a cheap wireless microphone, you may have to deal with high latency, which can be a problem while delivering a speech on stage.
#5. Type of Microphone
In the market, you will find two types of wireless microphones, i.e., analog and digital.
Analog microphones convert the acoustic wave into an electric signal via cables.
A digital microphone always produces a digital signal which transmits through the air to the receiver. The receiver receives it and converts it into sound. The main challenge for digital microphones is latency, though this becomes less of an issue with more expensive digital mics.
Why Are Digital Wireless Systems Better Than Analog Wireless Systems?
- Digital system microphones are always better than an analog system. It is so because the audio information is coded and decoded. Some digital microphones may involve encryption. Here the encryption means the data is jumbled up, which may be beneficial for a presentation in a business meeting. The company can maintain confidentiality with digital mics.
- Wireless systems always operate in fixed frequency bands. They may be licensed or unlicensed and shared with various technologies like radio and television. The bandwidth is limited in an analog system, whereas in a digital system is global and license-free.
- Digital systems are portable.
- Digital systems are more efficient in comparison to analog systems. They require less power to operate and have good battery life.
- You can easily filter the noise by the digital wireless microphones because this involves coding and encoding data.
Disadvantages of Wireless Microphones
- Wireless microphones usually have a short range.
- There are some places where the wireless microphone won’t work. Such locations are called dead spaces.
- Battery-operated wireless microphones usually won’t work during charging.
- You need to buy the receiver, transmitter, and mic from the same brand or the same manufacturer. If you mix other brands, then that may create interference. The receiver and the transmitter should operate at the same frequency.
Wireless microphones can be incredibly beneficial for the right user. With wireless mics, there is no hassle with tangled cables and no risk of tripping on stage. Lavalier mics or handset mics are two exceptional types of wireless mics that are great for delivering a presentation on stage.
I hope this article has given you some ideas related to the wireless microphone and how it works. Please do share your comments and suggestions for this article in the comments section below.