Preferred store
Updated , Sam Vafaei

What is Bluetooth?
Bluetooth Versions Comparison & Profiles

Bluetooth is the most common wireless communication technology available for mobile devices. It has progressively improved over the years with newer iterations, being able to support more features and profiles. However, it's easy to get confused in the terminology for the various components of Bluetooth. Here's a quick guide to get you up to speed:

Bluetooth Versions

 Bluetooth  Versions Optional Features Bluetooth Version description 
 
Basic rate (BR)
Enhanced Data Rate (EDR)
High Speed (HS)
Low Energy (LE)
Slot Availability Masking (SAM)
Note: The additional features supported by the higher versions of Bluetooth are all optional and do not affect the encoding and transmission of audio. Higher versions of Bluetooth are also backward compatible and will default to the available features of that Bluetooth connection.
Bluetooth 1.x
Yes
No
No
No
No
The basic Bluetooth rate with no additional/optional profiles or codecs. This version of Bluetooth is obsolete and was rarely implemented on mobile devices due to its limited speed of 1mbs and difficulty pairing.
Bluetooth 2.x
Yes
Yes
No
No
No
The most popular variant of Bluetooth, especially in the earlier days when phones were not as advanced. It supports enhanced data rates (EDR) up to 3 Mbps, and the V2.1 variant significantly simplified the pairing procedure making it a more practical for commercial use.
Bluetooth 3.x
Yes
Yes
Yes
No
No
Bluetooth 3.0 improves on the speed limitations of Bluetooth 2.1, with the optional High-Speed feature (HS), which allows the Bluetooth module to transmit over an adjacent radio (802.11). However, Bluetooth 3.0 consumes a lot more power than Bluetooth 2.x.
Bluetooth 4.x
Yes
Yes
Yes
Yes
No
Bluetooth 4.0 has the high-speed capability of Bluetooth 3.0 but also comes with a Low Energy feature to collect data from the sensors of low rate devices. This feature allows the Bluetooth module to reduce power consumption with connected devices like wearable smartwatches, heart monitors, mobile phones and smart headphones.
Bluetooth 5.x
Yes
Yes
Yes
Yes
Yes
The most recent iteration of Bluetooth, better suited for the Internet of Things (IoT). It's speculated to have twice the bandwidth of Bluetooth 4.2 LE and 4x the range. It also has a new feature called Slot Availability Masking (SAM) which can detect and prevent interference on neighboring bands for a more efficient use of broadcasting channels. However, we have yet to test the Bluetooth 5.0's capabilities for ourselves.

Bluetooth Profiles

HSP - Headset Profile - Basic headset functionality. This profile allows for a microphone input, and 64 kbps mono audio. 

HFP - Handsfree Profile - Advanced headset functionality. Adds more controls to the HSP profile like voice dialing, redialing and better mono audio quality.

A2DP- Advanced Audio Distribution Profile - Stereo audio transmission. This is the most important profile for Bluetooth headphones as mono audio is not suited for listening to music.

AVRCP - Audio/Video Remote Control Profile - Adds control for media playback such as skipping tracks, play/pause, and volume control. The latest version of this profile gives you direct control over the volume of your device instead of just the headset/headphones.

Note: There are a lot more Bluetooth profiles available, but we only listed those relevant to wireless Bluetooth headphones.

Bluetooth Codecs

Codecs are the encoding and decoding algorithms that compress data into manageable packets for faster and more reliable transmission. For wireless headphones, there are a couple of codecs to improve both sound quality and/or latency. Some companies have proprietary codecs like Samsung's UHQaudio and Sony's LDAC, however, the 3 main codecs that most listeners are familiar with are SBC (Subband Coding), AAC (Advanced Audio Coding) and aptX.

For more information on codecs check our SBC vs AptX article

How it works

The simplest explanation for how Bluetooth works is that data/audio is continuously transferred from a paired Bluetooth transmitter to a paired receiver. Pairing is just the bonding procedure between devices so that you don't have to enter access or security information, like passwords or passkeys, each time the devices need to establish a connection.

Bluetooth Pairing ProcedureBluetooth Pairing Procedure
Paired and playing musicPaired and playing music

Bluetooth operates in the frequency range of (2.402 -2.480GHz). Once a secure connection is established between a transmitter and receiver, data is split into small packets, which are then transferred at alternating frequencies. The type of Bluetooth and profiles may vary, but the core architecture remains the same.

 

To avoid interference with other devices that may also use the ISM (industrial, science and medical) bandwidth of 2.4Ghz Bluetooth devices randomly hop between frequencies 1600 times per second until all the packets are transferred.

ISM Band Frequency Range

Now that you have a better grasp of how Bluetooth works, you're probably wondering how it affects the sound quality of your headphones. Learn more about Wired vs. Wireless Headphones

Conclusion

Bluetooth is backward compatible, so in most cases, especially if you're only listening to audio, you don't need to worry about the different Bluetooth version, profiles, and codecs. However, if you usually interact a lot with your headphones, to make calls or control media playback then having all the necessary profiles will be important. Also, if you watch a lot of movies or game with you headsets then having additional low latency codecs will improve your viewing experience. But for just listening to audio, any Bluetooth headphone should be suitable, so your choice of headphone should depend more on their sound quality and your preference.

Check our recommendations for the best Bluetooth headphones.

Questions Found an error?

Let us know what is wrong in this question or in the answer.

Email:

Questions & Answers

0 ANSWERED QUESTIONS
Questions Have a question?

Before asking a question, make sure you use the search function of our website. The majority of the answers are already here.

Current estimated response time, based on # of pending questions: 3.8 business days.

:
:
A valid email is required. We answer most questions directly by email to prevent cluttering the site.