How Do Wireless Headphones Work

This article is about how do wireless headphones work. Wireless headphones have been around since the 1960s. However, in 2004, wireless Bluetooth technology headphones entered the market and revolutionized personal audio listening, gaining popularity among audio users and professionals alike.

If you’ve ever wondered how do wireless headphones work or earbuds play audio from your device, this article is for you. We will discuss wireless transmission methods and wireless headphone design, as well as the advantages and disadvantages of going wireless.

How Do Wireless Headphones Work

What is the Working of Wireless Headphones

It is very easy to know how do wireless headphones work. Wireless headphones work by receiving signals sent wirelessly from the audio source with which they are paired. These signals are encoded by the source device and transmitted to radio frequency (normal) or infrared (less common) carriers.

Wireless headphones receive an RF or IR signal and decode it into audio. Wireless headphones have built-in receivers designed to accept radio waves that carry audio signals to drive headphone drivers. This “wireless signal” is called the carrier.

Transmitters effectively encode the audio signal in a wireless format (carrier width) and transmit the wireless signal over the air. The desired audio signal is known as the modulation signal. This modulation signal is encoded into a carrier wave which is transmitted wirelessly to the recipient.

Carriers are used to transmit wireless headphone signals either in the radio frequency range or in the infrared frequency range.

Note: The carrier is the only frequency wave within the above range. Audio signals typically consist of frequencies in the audible range from 20 Hz to 20,000 Hz.

In wireless headphones, the receiver reads the carrier wave width and decodes the wave modulation signal (audio signal). The wireless receiver must be set to accept a specific carrier frequency.

If the audio signal is digital, it is converted to an analog audio signal. The analog audio signal is then amplified so that the headphone drivers can run properly.

It is important to note that regardless of the specific type of wireless headphones, being wireless means that the headphones are active. In other words, they need strength to function properly.

To maintain the “wire authorization” of the headphones, it is necessary to supply power through the internal battery. These can be AA or AAA batteries, or batteries inserted into the headphones. However, today’s infrared wireless headphones have a built-in rechargeable battery.

How Do Wireless Headphones Transmit Audio Signals

Wireless headphones work the same way as wired headphones, except for the method of transmitting the audio signal from the source headphones and the internal DAC/amplifier. Wireless headphones have mixed reviews about better sound quality.

So, in a nutshell, let’s look at the historical milestones involved in transmitting audio over a wireless headset to know better how do wireless headphones work.

Step 1: The audio source sends its audio signal to the wireless transmitter.

Step 2: The radio transmitter encodes the audio signal (modulation signal) into the carrier width.

Step 3: A single-frequency carrier wave propagates in space.

Step 4: The radio receiver, which is designed to capture the single-frequency carrier wave, accepts the radio signals and decodes the audio signals efficiently.

Step 5: The digital audio signal is then converted from the digital to analog converter (if the wireless headphones are designed for this).

Step 6: The internal amplifier amplifies the analog audio signal.

Step 7: The amplified audio signal is sent to the wireless headphones’ drivers.

Step 8: The wireless headphones drivers (transducers) convert audio signals (electrical energy) into sound (mechanical wave energy).

What is the Role of Carrier Waves & Modulating Signals in Wireless Headphones

To understand wireless headphones and wireless signal transmission in general, we must understand carrier waves and modulation signals. Carrier waves are electromagnetic waves that are modulated by informational signals for radio transmission.

As its name suggests, carriers carry the wireless headphones signal from the transmitter to the receiver. Vibrating electric charge produces electromagnetic waves. Vibrations of electric charge contain both electrical and magnetic components.

These waves carry energy from one place to another. It could be heat and light from the sun to the earth or wireless sound from the transmitter to the headphone receiver.

Unlike sound waves, which are mechanical waves, electromagnetic waves can travel through space and do not interact directly with the molecules of the medium (although atoms inside the medium will absorb the energy of some electromagnetic waves).

Wireless headphone mount signals are usually either the waves of radio (normal) or infrared waves (rare). Radiofrequency (RF) ranges from 30 Hz to 300 GHz (300,000,000 Hz). Infrared (IR) frequency range from 300 GHz to 430 THz.

Whether the wireless headphones connect uses RF or IR, the carrier wave is a sine wave with a signal frequency. The transmitter is set to transmit a single-frequency carrier, and the receiver is set to accept a single-frequency carrier.

Hertz is a measure of cycles per second. Wireless headphones typically operate around 2.4GHz, providing an excellent wireless range of up to 91 meters (300 feet).

Modulation signals, as the name implies, are used to modulate carrier wave signals. This modulation signal is then effectively transmitted from the radio transmitter to the receiver via the carrier.

In the case of connecting wireless headphones, the modulation signal is an audio signal intended for headphone drivers. There are several ways in which a modulated signal can modulate a carrier in wireless headphones.

What is Wireless Analog Audio Transmission

For transmitting wireless analog audio signals in headphones, frequency modulation is most common. Yes, FM radio uses the same transmission that makes RF FM wireless headphones sound like mini radio stations!

Frequency modulation (FM) modulation works by modulating the signal to a frequency across the width of the carrier. Therefore a “single-frequency” carrier must operate within a range of frequencies once modulated by the signal.

The receiver is designed to accept the carrier bandwidth. To try and shorten the carrier frequency difference in a wireless headphone, the audio is amplified only when the headphone receiver demodulates it.

Wireless headphone signals are almost always stereo. Fortunately, FM carrier signals can be used to transmit stereo audio. This is done by multiplexing and demultiplexing before and after the frequency modulation process.

Multiplexing is an efficient combination of multiple mono or polyphonic signals combined into a single signal with the help of wireless technology. With proper multiplexing and demodulation, the actual FM modulation and demodulation operations are identical in stereo and mono operations.

What is Wireless Digital Audio Transmission

With the advent of digital audio and digital audio devices, many wireless headphones are now designed to accept digital audio analog signals wirelessly. Digital audio is basically a digital representation of analog audio.

Analog sound consists of continuous waves of alternating current. Digital audio takes instant snapshots of signal amplitude and displays them digitally. Digital audio quality can be determined by sample rate and bit depth.

Sample rate refers to the number of individual sound amplitudes per second. Typical sampling rates include 44.1 kHz and 48 kHz. In this case, Hz means sample/second.

Bit depth refers to the number of bits used to indicate the dimensions of a given pattern. Bits refer to the number of binary digits (1 and 0) tied together to represent a value. Ordinary bit depths include 16 bits (containing 65,536 different values) and 24 bits (containing 16,777,215 different values).

The higher the sample rate and bit depth, the higher the resolution, and in theory, the higher the quality of the digital audio signal.

Note: The higher sampling rates and even a little depth require more processing power and different sampling rates do not match.

For now, though, we’ll talk about the actual digital transmission method used to transmit audio from a device to a pair of wireless headphones because Bluetooth is so popular. Of all the different ways to transmit digital audio wirelessly, pulse switching switch (PSK) modulation is the most popular.

PSK provides digital data by modulating the single-frequency carrier view phase. Adjustments are made by changing the sign and cosine input at a given time.

PSK transmits digital data by modulating a single frequency carrier phase. Modulation is achieved by changing the sign and cosine inputs at specific times depending on the binary code of the digital signal.

Some Important Points

To recreate your section for modulating signals and carriers for wireless headphone transmission, let’s look at some tips:

  • The desired signal acts as a modulation signal and can be analog or digital.
  • The carrier signal used with wireless headphones is usually a radio signal of 2.4GHz. Carrier signals can be in the frequency band of radio or the infrared frequency band.
  • Analog audio is typically transmitted over radio frequencies using frequency modulation in wireless headphones.
  • Bluetooth typically transmits digital audio by modulating the pulse switch.
  • Wireless headphones can transmit FM and PS stereo audio.

What is the Role of Transmitter in Wireless Headphones?

In wireless headphones, a wireless transmitter is responsible for converting the audio into a wireless format in wireless headphones. In the above section, we learned that it involves carrier modulation by means of an audio signal.

Transmitters can be independent devices that are attached to audio sources. These stand stone wireless headphone transmitters are popular for use at home and with professional in-ear monitoring systems.

Alternatively, transmitters can be built directly into the audio equipment. The same is true of most devices sold as wireless, and this is almost always the case with Bluetooth wireless headset. Your headphones connect with your mobile devices over a wifi network or other signal range.

Transmitters are typically designed to transmit analog or digital audio signals wirelessly and typically operate within a limited range that is compatible with the asynchronous receivers. In some transmitters of wireless headphones, the frequency of a carrier signal can be changed or “tuned” by the user to a specific frequency.

How Does Receiver Work in Wireless Headphones

Wireless headphone receivers are integrated into the headphones themselves. There are also wireless receiver units that can be connected to wired headphones, although these systems are not completely “wireless”.

The receiver is designed to efficiently capture the carrier wave sent by the transmitter. Its role is to decode the audio from the carrier signal. As mentioned earlier, for wireless transmission to function properly in wireless headphones, the transmitter and receiver must be on the same frequency.

The recipients are designed to decrypt certain types of modification. For compatibility with transmitters, analog receivers usually decode the FM signal (in the frequency range of radio). In contrast, digital receivers usually decode PSK signals.

For example, Bluetooth headphones have PSK receivers that accept RF frequencies between 2.400 and 2.4835 GHz.

What is the Working of Radio Frequency Transmission

To reiterate, radio waves are electromagnetic waves with a frequency range of 30 Hz to 300 GHz. These electromagnetic waves carry energy with them and create duplication in their electromagnetic fields. They are emitted naturally in all directions, and in space, they travel at the speed of light.

In a medium such as air, electromagnetic waves travel very slowly but still incredibly fast, due to interference from medium particles. Although the wireless frequency range is 30Hz to 300GHz, most RF headphones operate in the 900MHz to 3.2GHz range, depending on the model.

The wireless Bluetooth standard operates between 2.400 and 2.4835 GHz. RF wireless headphones often receive wireless without an analog audio signal. The best examples of wireless headphones are Sennheiser RS ​​175 headphones.

As mentioned earlier, these signals are transmitted wirelessly through frequency modulation:

  • The audio signal in wireless headphones (usually covering the range between 20 Hz and 20 kHz) acts as a modulation signal.
  • Carrier View is in the 900MHz to 3.2GHz range.
  • The amplitude of the audio signal changes the frequency of the carrier wave.
  • The wireless headphones receive the modulated carrier, and the audio signal is received from the carrier.

To transmit a stereo audio signal (which can be considered as two separate mono signals) in wireless headphones, the transmitter must have a transmitting multiplexer that effectively combines the left and right channel signals into a single modulation signal.

Radiofrequency is commonly used to transmit voice and other signals in wireless headphones because it is very efficient. Their relatively long waves (compared to other electromagnetic waves, compared to sound waves) allow them to travel long distances and penetrate solid materials (walls, floors, etc.).

A typical 2.4GHz wireless transmitter can transmit a signal of 91 meters (300 feet) or more. RF transmitting waves can also be picked up by an almost unlimited number of RF receivers if they are all of an appropriate frequency.

The range is only theoretically a consequence of the physical space the receiver takes up compared to the amount of the frequency of the radio carrier wavelength band.

However, the popularity of the frequency of radio causes a major drawback. The downside is that wireless headphones’ RF signals are sensitive to interference from all other devices that transmit sound at or near the transmission frequency.

It is important to note that the most popular Bluetooth standard transmits information over the waves of radio for good sound quality. However, this standard is generally separated by the frequency of the radio, and therefore it is able to differentiate Bluetooth headphones from RF headphones.

What is the Working of Infrared Transmission in Bluetooth Devices

Again, infrared (IR) waves are electromagnetic waves in the frequency range from 300 GHz to 430 terahertz. Infrared waves have higher frequencies than the waves of radio and therefore shorter wavelengths. Infrared waves behave differently than radio waves, so let’s talk about them.

One important difference between IR and RF is that IR is the line of sight. If a physical object receives an infrared transmitter from an infrared receiver, there will be no signal transmission. This is mainly due to the short wavelengths and the relatively weak infrared wavelengths.

Another effect of short infrared waves is that the transmission range is good only up to 10 meters (32 feet), as is the 91 meters (300 feet) or more available for RF.

This short white line is a major drawback for many applications, but it can be very useful if privacy is required. IR headphones are commonly used in small rooms and connect wirelessly to televisions and other audio channels in cinemas, boardrooms, and courtrooms.

Only wireless infrared technology can establish a connection between a transmitter and a receiver. The Unisar J3 TV920s is an example of a wireless infrared headphone.

Because the infrared wireless area operates much less than the frequency area, infrared wireless headphones are less sensitive to interference and often provide superior sound fidelity.

Advanced wireless infrared headphones can greatly improve RF headphones in terms of sound quality, but only to a limited extent of the transmitter.

What is the Transmitting Procedure From the Bluetooth Device to Headphones

Bluetooth has become the standard for most wireless headphones, so it’s important that we talk about wireless technology. Firstly, the quality of Bluetooth is constantly being improved, and there are many different versions.

The Bluetooth Special Interest Group and the engineers responsible for the development of Bluetooth technology ensure cooperation between the versions. However, when we pair the other electronic devices with different BT versions, we only get the benefit of the older version.

Unsurprisingly, there are many different standards for the overall quality of Bluetooth. If you are a bluetooth expert, please bear with me as I focus on the standards commonly used for wireless headphones.

For everyone else, know that there are other standards, and no particular pair of Bluetooth headphones will fit the description. With that, let’s take a look at how wireless Bluetooth headphones work!

Works in conjunction with Bluetooth devices. Wireless headphones must be connected to a Bluetooth-enabled device in order to transmit information (audio).

A Bluetooth network connection is called a piconet, and information is transmitted in one direction. The audio device primarily controls the wireless headphones.

Bluetooth transmits digital information over short-range radio frequencies in the 2.400 to 2.485 GHz frequency range. In the case of wireless headphones, this information is a digital audio signal from a paired device.

Bluetooth uses 79 distinct frequencies in the range of 2.400 to 2.485 GHz to transmit information. It can change this frequency up to 1600 times per second to avoid interference with other Bluetooth connections.

It is unlikely that two transmitters can be on the same frequency at the same time. This minimizes the risk of interference between Bluetooth devices because any interference at a particular frequency will only last for a fraction of a second.

Beats Solo Pro is a great example of wireless Bluetooth headphones.

As mentioned above, BT transmits digital information wirelessly. Bluetooth audio is sent via Pulse-Shift Keying Modulation (PSK). It is a digital audio modulated signal coupling device. This modulation signal controls the stage of the fixed frequency carrier.

It does this by changing the sine and cosine inputs at the same time. For Wireless Bluetooth headphones, this means that the digital audio signal operates on one of 79 radio frequencies, changing 1,600 times per second.

This apparently offline wireless connection works well for wireless audio transmission. Most Bluetooth headsets are Class 1 or Class 2 devices. This means that the maximum power allowed to transmit the signal between wireless headphones and the paired device is 100 mW (Class 1) or 2.5 mW (Class 2) and Class 1 or 10m (33).

The distance is about 100 meters (330 feet). ) is the range of the signal. feet) for class 2. This low power consumption allows for extended battery life. Sound beats Q30HD is an example of the Wireless Bluetooth Headphones.

Bluetooth provides a standard for communication between wireless headphones and digital audio devices, as long as the technology is present in both devices. It provides better sound quality and is constantly being improved, although Bluetooth has not yet reached the level of a wired connection.

Note: The other electronic devices paired with bluetooth will drain more battery than a wired headset.

What is the Difference Between Wireless and Wired Headphones

Both wireless headphones and true wireless earbuds work on the same principles as wireless audio transmission. However, there is a big difference. True wireless earphones consist of two independent earpieces that are not physically connected.

This means that wireless headphones have their own receiver, and this receiver must decode its appropriate channel (left or right) from the transmitted carrier signal. Each earpiece also has an amplifier for drivers to handle the audio signal properly, and a DAC if digital to analog conversion is required.

This is different from most “normal” wireless headphones, which have a single receiver and decode the stereo audio signal from the carrier signal before sending the appropriate channel to the appropriate drivers.

Bang & Olufsen Beoplay E8 is an example of real wireless Bluetooth headphones.

Advantages and Disadvantages of Wireless Headphones

Continuing from the top wired versus wireless headphones, let’s quickly talk about the advantages and disadvantages of wireless headphones.

Advantages of Wireless Headphones

The advantages of wireless headphones include:

  • The Bluetooth standard (now used in most new wireless headphones) is compatible with many popular audio devices today.
  • The sound of the device is not taught.
  • Bluetooth (Class 2) typically allows up to 10 meters (32 ft).
  • RF (about 2.4 GHz) allows for a range of up to 91 meters (300 feet) or more.
  • IR allows a range of up to 10 meters (32 ft).
  • Disadvantages of Wireless Headphones

The disadvantages of wireless headphones include:

  • Batteries are required to operate in wireless headphones, which require regular replacement or recharging.
  • The device that is paired with the Bluetooth standard is also running out of battery.
  • High price point due to the built-in receiver and amplifier (and possibly a DAC).
  • Connecting wireless headphones slower than wired headphones can be a bit frustrating.


This was all about the working of wireless headphones. I hope after reading the complete article you must have learned how do wireless headphones work. Using wireless headphones is much more comfortable than wired headphones and you should have a wifi network to listen to songs online on your mobile devices if you have rf wireless headphones for better sound quality.

So what do you think about wireless headphones? Have this article helped you to understand how do wireless headphones work? Let us know your reviews about wireless headphones working in the comment section below.


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