The most common technology that makes headphones wireless is Bluetooth. Most people associate the name with hands-free devices for cell phones. Bluetooth is a wireless technology standard, created to exchange data over short distances. It was specially designed to have low-power consumption. When talking about wireless earbuds, there are two types of devices involved – a transmitter and a receiver. A transmitter is any source of music – for example, a smartphone, tablet or an iPod – that can stream Bluetooth audio. A set of headphones is an example of a receiver.
Bluetooth versions
Pay attention to Bluetooth versions. They normally range from 1.0 and up. The most current version is 4.2.
An update from Bluetooth 2.0 to 2.1 brought considerable simplification of the pairing process and improvement of battery life. Therefore, any Bluetooth version below 2.1 is not recommended (keep in mind that this version was released in 2007). Version 2.1 and higher should be fine for wireless headphones, though each subsequent version brings a slightly more stable connection and better battery life. For example, the power improvement handling of Bluetooth 3.0 was done to reduce the possibilities of streaming interruptions, such as putting a phone into a pocket, which requires a sudden jump in transmission power.
It is also important to note that the Bluetooth Low Energy technology (BLE), which was introduced in Bluetooth 4.0, was designed for sensors and periodic data transfers. It is not suitable for streaming high bandwidth stereo music.
Bluetooth Audio Quality
The basic codec used to encode the audio signal is called SBC, which allows audio to stream with the maximum bit rate of 345 kbit/s. This is fine if music is kept in mp3 files, but would reduce the quality for one who prefers lossless formats. There are other codecs, such as AptX, which allow pure CD-quality over Bluetooth, but they are more common for larger HiFi devices (i.e., loudspeakers or On-Ear headphones). Here is a resource to search for AptX compatible devices; just keep in mind that both devices (transmitter and receiver) must be AptX compatible (look for AptX in technical specification). A short note before you open up the list – iOS devices do not support AptX, but they support another codec, called AAC. This codec is also able to provide a better quality than SBC, however not many wireless earpieces seem to support it.
For further reading, check out Bluetooth audio quality – A2DP on SBC fidelity; Audio quality of Bluetooth AptX on AptX; and the official AptX Blog.
Bluetooth Profiles
Bluetooth profiles define which functionalities are available on the device. Only the profiles necessary for wireless earbuds are listed here. Most stereo headsets support them. The detailed list of Bluetooth profiles can be found on Wikipedia.
- Headset Profile (HSP)– basic headset functionality.
- Hands-Free Profile (HFP)– a more advanced version of HSP, which includes additional functions such as redialing and voice dialing.
- Advanced Audio Distribution Profile (A2DP)– multimedia audio streaming.
- Audio/Video Remote Control Profile (AVRCP)– standard profile to control TV and HiFi equipment (used together with A2DP).
Pairing Bluetooth headphones
Before wireless headphones can be used, they need to be connected to the transmitter device – a phone or a compatible mp3 player (such as an iPod). This process is called “pairing”. It needs to be performed only once for a smartphone/headphone pair.
Here is the general procedure for pairing Bluetooth devices. It may vary slightly from device to device. The exact procedure can be found in the headphone’s manual or on the headphone manufacturer’s website.
- Wireless headphones first need to be switched to pairing mode. Follow the instructions provided with the headphones to do it. This process normally looks like this:
- Make sure the headphones are turned off.
- Hold the headphone power button for more than four seconds.
- If the headphones have a led indicator, it will flash, showing that the pairing mode has been enabled.
- Bluetooth needs to be enabled on the smartphone. Access the system settings of the smartphone (Settings-> Bluetooth on iOS, and Settings -> Connections -> Bluetooth on Android).
- The headphone name should appear in the Bluetooth menu of the smartphone. Click it and wait until the devices are paired. In some cases, you may be prompted to input a PIN. In this case, try to enter either ‘0000’ or ‘1234’ (or refer to the headphone documentation to determine the passkey).
- When the pairing is complete, you can use the Bluetooth headphones with your smartphone.
If you are still experiencing problems with pairing, here are some useful resources for further reading:
A guide on pairing apple devices
A video guide on connecting Samsung devices to WiFi and Bluetooth
Some advanced models of Bluetooth earbuds have NFC technology. This means it is enough to tap your mobile phone with the earphones to trigger the pairing. Please note, though, that the mobile phone must also support NFC. For example, it is supported by iPhone 6 and Samsung Galaxy S4/S5. The full list of NFC compatible phones can be found on Wikipedia.
Conclusion
The wireless headphone market has boomed in recent years, creating compact and competitive gear. There are many technical aspects to consider when choosing the right Bluetooth earpiece. Always keep an eye on the following parameters, in addition to the normal parameters of wired headphones, when considering a purchase:
- Bluetooth Version
- Bluetooth Profiles
- Battery Life
- AptX or AAC codec (depending on your smartphone model, if concerned about sound fidelity)
For more information on Bluetooth, visit the official Bluetooth website.
Also look at the 5 parameters of the best running headphones to see what defines the greatest running earbuds.
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