The development of wireless data transmission and the reduction of batteries in size has allowed engineers to make affordable and functional wireless headphones. Such models have no wired connection to the sound source – a smartphone, laptop, or computer, which is great if you want to listen to music and read a Big Bamboo slot review or watch TikTok at the same time. What exactly is the signal transmission method used and what to look for when buying – we tell you in detail.

Signal Transmission Method

An infrared transmission channel provides an average range of up to 10 meters. It works by analogy with the remote for the TV. A complete module with an infrared emitter is connected to the playing device.

The signal is transmitted in the optical range and is picked up by a special sensor on the headphones. The key advantage of this technology is the high data transfer rate of up to 10 Mbps, which allows you to enjoy tracks with high bitrates.

However, headphones with IR data transmission have all but disappeared. Since the infrared signal is critical to obstacles in the path, even careless head turns could lead to signal loss, and using such models with smartphones was out of the question.

The radio headphones use a frequency range of 800 MHz to 2.4 GHz, which provides a real range of 100-150 meters. The signal also handles a variety of obstacles well, with the exception of reinforced concrete structures. The radio headphones always work in pairs with a special transmitter. The latter is connected to a source (TV, laptop, or computer) and usually requires a separate power supply.

Almost all radio headphones are quite bulky devices. They are best suited for stationary use. They are a great option for watching TV, movies, and shows on your laptop or computer. The high range allows you to walk around different rooms practically unobstructed while you talk – important for those who often work at home.

The disadvantages of wireless headphones include signal vulnerability to interference, which translates into poor sound quality, but this isn’t true for all models. In terms of the phone conversation, gaming, or watching movies isn’t critical, but for listening to music, these models are not the best choice.

Bluetooth headphones are the most popular and demanded type. The theoretical range of the fifth version of Bluetooth reaches up to 400 meters. However, in practice, taking into account obstacles, users can count to 10-30 meters.

Pay attention to headphone profiles and codecs when purchasing. Bluetooth profiles are sets of instructions that define the features available between source and receiver over a Bluetooth connection:

  • HFP, Handsfree – The profile is used to connect car handsfree kits to cell phones in the car. It typically uses a channel-oriented synchronous connection (SCO) to transmit a monaural audio channel. It isn’t a priority in headphones.
  • A2DP is an improved audio transmission protocol. It provides better sound quality and is capable of transmitting stereo sound. Important profile for headphones.
  • HSP, Headset is the basic protocol for transmitting telephone AT commands, allows the phone to make and answer calls, adjust the volume, and more. A must if the headset is to be used with a smartphone. This is an important profile if you are buying headphones to pair with your smartphone.
  • PBAP – allows the headset to access the phonebook of your smartphone, speak the name of the caller, and so on. An important profile for Bluetooth headsets.
  • AVRCP is a control protocol that allows you to send playlist control commands. Important profile for listening to music and controlling the player.

The Bluetooth codec determines the bitrate – the number of bits transmitted per unit of time, which affects the sound quality. The higher the bitrate, the better and richer the sound of the track will be.

Form Factor

The usability of wireless headphones doesn’t only depend on how the signal is transmitted. The design is also important – here we can distinguish several types of headphones:

  • Full-sized – covering and overhead. Available both with Bluetooth module and radio transmitter. The models are characterized by maximum comfort at the expense of large earpads and the possibility of adjusting the headband. Can be fitted with a remotely adjustable microphone. They provide good noise isolation.
  • Compact. This category includes wireless headphones with a shackle on the back of your neck or neck. They are only available with a Bluetooth module, are lighter than full-size headphones, and are great for listening to music while on the move.
  • Ultra-compact. This is the TWS category – they are the most compact and work only via Bluetooth. Quality models can be used for both gaming and listening to music. TWS wireless headphones have a worse fit in the ear, and earmolds are also not the best noise isolation.

Full-size headphones because of their size are suitable for gaming, watching TV, and working with a laptop/computer. Compact and ultra-compact wireless headphones are best paired with mobile gadgets.

Acoustic Parameters

Power

The more watts your wireless headphones can deliver, the louder the sound you’ll hear. Most compact and ultra-compact models have less than 10 mW of power, and full-size models have 30 mW. Remember that high power leads to a fast drain on the battery.

The transmitter (speaker) is the heart of any headphone. The quality of playback of individual audio tracks depends on the design. There are three basic types of transducers:

  • Armature – provides clear sound and excellent transmission of upper and middle frequencies.
  • Dynamic – the most common models and perform best in the low frequencies, but don’t always produce high frequencies.
  • Hybrid – expensive models that perform well across the entire frequency spectrum.

Sensitivity

The characteristic indirectly affects the playback volume. Typical values are 85-120 dB. The higher the parameter, the more volume the headphones can provide. Sensitivity is partly a relative parameter because it also depends on the resistance of the headphones.

Impedance

For compact and ultra-compact models, the impedance does not exceed 32 ohms. Full-size models can have an impedance of 32-58 ohms. There is a rule of thumb: with the same sensitivity of the two models, the volume will be higher with the headphones with lower impedance. However, headphones with low impedance have higher power consumption, which will affect battery life.

Frequency Range

The standard frequency range is 20-20000 Hz. These frequencies can be heard by the human ear. On sale, you can find models with an extended range – of 4-48000 Hz. Such headphones provide a richer sound in extreme frequencies, but they are also more expensive.

Microphone

This is an optional attribute in wireless headphones, but if you plan to use them as a headset, we recommend paying attention to the characteristics of the microphone. Full-size models (overhead and girth) often have a remotely adjustable microphone – this is useful for gamers and provides better hearing. It can be removable and even have a windshield.

The key to a microphone is its sensitivity. A high sensitivity will allow you to speak more softly during a conversation. It’s measured in dB – the closer the value is to zero, the higher the sensitivity.

35 dB is considered excellent for compact and ultra-compact models of wireless headphones. And for devices with a retractable microphone, this value can be even higher up to 60 dB.

Autonomy

The longer the battery capacity, the longer the wireless headphones will be able to work.

Full-size radio and Bluetooth headphones usually boast the highest capacity battery up to 750 mA*h, which provides up to 20 hours of battery life. Cheaper models have a battery of up to 500 mA*h – that’s an average of up to 14 hours without recharging.

Earbud headphones with a relatively small battery of 150 mA*h offer 12-16 hours of operation without recharging. Ultra-compact (TWS) headphones are rated at 4-8 hours, but the included case allows for recharging – that’s up to 24 hours of use.

Additional Features

Active Noise Cancellation System

A priority feature for those who plan to listen to music in noisy environments, such as public transportation or on the street. 

Voice Control

It allows you to switch tracks, answer calls and control your smartphone by voice. If you use headphones paired with another device (laptop, computer, TV), it may not be relevant.

NFC 

Some headsets can be paired with gadgets via NFC — it’s much faster than Bluetooth.

Multipoint Function

It allows the headset to connect to more than one device. Only relevant for Bluetooth headphones.

Transparent Mode (Talk Through) 

In contrast to noise cancellation, it amplifies external sounds, allowing you to hear your surroundings without removing the headphones. Important for full-size headsets and models with earpieces and clips, as they are difficult to remove quickly. It’s much easier to switch to Talk Through.

Wireless Charging Support

Useful if you don’t want to bother plugging in a charging cable every time your battery runs out. Relevant for ultra-compact (TWS) and single full-size wireless headphone models.

Built-in MP3 Player

Useful if you want to use the headphones standalone without pairing them with a smartphone or other device. Internal memory allows you to store tracks directly on the headphones.

Wired Connection

Many wireless full-size headphones are equipped with a jack of 3.5mm or other. This is a good alternative, especially for using headphones paired with a laptop and PC.