Ask any average audiophile, and they will immediately recite that wired headphones will provide better quality audio than wireless ones. He is indeed right, since transferring information wirelessly often requires changing the analog signal and compressing it to digital, which affects the audio quality. But the world has moved on and probably the next pair of headphones you buy will be wireless. So how do you recognize the differences between the headphones and what do the different devices even mean? the guide.
A quick look at the Bluetooth headset packaging on the market reveals various markings, often consisting of several letters. In many cases these letters indicate the codec supported by the headphones. The word, which according to some opinions was created from the combination of the words compressor-decompressor (compresses and extracts from compression, loosely translated), describes various protocols that are used by the manufacturers of Bluetooth headphones in order to transmit quality audio in them despite the limitations of the technology.
Among the various parameters in which wireless sound will be tested, you can find the “resolution”, the amount of information that is in the sound file and describes how accurate and detailed it is. The sound resolution, or as it is more accurate to call it – the sampling depth – is measured in bits; The sampling rate describes the frequency of the analog signal – how much data is sampled in it every second, and it is measured in kilohertz; The data transfer rate is measured in kilobits per second; And the delay is the time that passes from the moment of transmission to the time when the signal is received, it is measured in milliseconds.
The manufacturers of the headphones, as well as the mobile devices, have adopted over the years different encodings to perform the compression and extraction, making an effort to excel in a variety of parameters from those we mentioned above. These are the main ones, combining their advantages and disadvantages.
AptX
The chip manufacturer Qualcomm is behind this popular encoding whose acronym stands for Audio Processing Technology. It is characterized by high sampling depth, as well as low latency.
Headphones that support AptX coding are required to meet the standard set by the company for a data rate of 384 kilobits per second, a sampling rate of 48 kilohertz and a resolution of up to 16 bits. In AptX HD coding, the headphones will support a resolution of up to 24 bits, with a data transfer rate of 567 kilobits per second and a sampling rate of 48 kilohertz.
The latency in these two sub-codings is between 170 and 270 milliseconds, but for gamers the company also offers AptX LL. The acronym means Low Latency – up to 40 milliseconds.
The disadvantage of AptX is that Apple devices do not support it, and therefore whoever connects headphones that use this encoding – they may work, but the users will not enjoy a significant audio advantage.
The company has other new versions of their encoding, such as AptX Lossless which is intended for audio streaming services, or AptX Adaptive which also knows how to reach a data transfer rate of 420 kilobits per second, but also knows how to adapt to older versions of AptX, so if the device supports AptX Adaptive And the headphones in AptX HD – there will be no problem listening to them in AptX HD quality.
LDAC
The person behind this coding is Sony, and it can be found in some of the company’s headphone models. It offers a high data transfer rate of up to 990 kbps, with 16-bit resolution and a sampling rate of 48 kHz. Most Android devices running OS version 8.0 and above incorporate this coding, and if the headphones support it – it will be possible to listen to quality audio.
Headphones that support this encoding will also not produce the most if they are connected to Apple devices, as these do not include LDAC support.
AAC
Apple users get a significant advantage in this encoding, whose acronym stands for Advanced Audio Codec. This is the standard encoding on iPhone and iPad devices, but Android devices and computers also include support for it.
It supports a data rate of 320 kilobits per second, a resolution of 24 bits and a sampling rate of 96 kHz, and is based on models that compress only the elements that humans are able to hear. These models require more powerful processing power, and they make the most of it mainly on iPhone devices.
SBC
This encoding belongs to the A2DP audio distribution profile and includes the minimum requirements in terms of encoding. It does not require a user license from the manufacturers, which makes it common mainly in the cheap headphones. Its compression is aggressive, and the result is evident in the sound quality – since it is possible to stream at a rate of up to 345 kilobits per second, and the sampling rate is 48 kilohertz.
And what do we do with all this information?
This list is only a summary of the popular encodings that are supported among headphones, computers and smartphones. There are other protocols, and from time to time new ones are added to the growing list.
The sampling rate is perhaps one of the most important features of any encoding, and the higher it is, the better quality sound you will hear. However, it is important to make sure that both the music source and the headphones speak the same language, and this is where the matter becomes a little complex: iPhones will often support the popular and free (and lower quality) SBC encoding along with the (high quality) AAC encoding. If you are purchasing headphones for a device of Darkyou should make sure that these supportAAC to get the ideal sound.
comparison table
| Coding | sampling rate | supported by |
| SBC | 320 | Android, iOS |
| AptX | 352 | Android |
| AptX HD | 576 | Android |
| AAC | 250 | Android, iOS |
| LDAC | 990 | Sony, Android |
Most devices the android They did not know how to deal with AAC effectively. In its place you will mostly find support for one of my codes AptX or LDAC Therefore, when purchasing headphones, it is recommended to note that they have one of these technologies. Of course there is also support for the free SBC encoding and other formats (depending on the manufacturer).
And while the manufacturers brag about the technology their products support, the average user will have to dig through complicated menus to find out in which coding the Bluetooth communication is carried out with the accessory connected to the device. This is how it is done on Samsung devices (and similarly on other Android devices). Let’s go ahead and say that this is using “developer mode” and wandering through these menus is not recommended for novice users. In any case, the TGspot team will not be held responsible for any damage caused as a result of these instructions.
at the entrance to the menu Definitions > About the phone > Software details > Clicking 7 times on the menu Build version number. Now, at the end of the main settings menu, the menu will appear Options for developers > under the submenu network communication must be clicked on Bluetooth audio codec.