WHAT IS BLUETOOTH APTX?
The popularity of wireless headphones grows every year. The trend is due to the convenience of its use, since the method of communication with the device via Bluetooth does not imply interference with cables, which gives the user greater freedom of movement.
Little by little, smartphone manufacturers are ditching the 3.5mm headphone jack as well, forcing modern device owners to keep up. That said, sound quality doesn’t always come with comfort. Good classic headphones often outperform their wireless counterparts on this parameter. But with the recent arrival of lovers of Qualcomm AptX technology to listen to music, headphones no longer have to choose between sound quality and ease of use. Now AptX, as well as AptX HD, can be seen more and more in the specifications of the devices. What is technology, how does it work and what is needed to assess its capabilities, we will consider.
What you need to know about listening to wireless audio
Let’s start with what Bluetooth is. This is a form of wireless data transmission over a short distance between compatible devices. The standard refers to wireless personal area networks (WPAN) and allows communication using radio waves. Radio communication is implemented in the ISM range of 2.4-2.4835 GHz, and is used in various devices, including home appliances, smartphones, computers, and others. However, the Bluetooth protocol supports point-to-point and point-to-multipoint connections. Full music streaming via Bluetooth technology is ensured by the following sound quality characteristics:
Sampling (or sampling) frequency. This is the number of sound volume measurements per second, that is, the frequency with which the analog signal is converted to a digital matrix. The parameter is measured in hertz or kilohertz (Hz, kHz). Therefore, the higher the sampling frequency, the better the sound is transmitted.
Audio encoding depth (sampling bit depth). This is the amount of data required to encode the discrete levels of digital audio loudness, measured in bits. In simple words, the bit depth determines the measurement precision of the incoming signal and the higher the bit depth, the higher the sound quality and at the same time increases the volume of the sound file.
Information transfer rate or bit rate. This is the amount of data transmitted per unit of time. In this case, we are talking about the transfer of audio data from the device to the headphones. That is, the higher the value, the more data is transmitted and processed during the same time, which improves sound quality. Bit rate is measured in kilobits per second (kbps or kbps).
Now let’s consider what this AptX Bluetooth technology is. This is an audio codec from Qualcomm that allows you to transfer, compress, and decompress high-quality audio files via Bluetooth. So, using technology, it was possible to achieve a better sound, this is ensured by the fact that there are practically no losses at the time of conversion to digital, so the difference from the standard Bluetooth codec (SBC) is noticeably felt. . The enhanced version of AptX HD uses dynamic encoding, where most of the data is encoded losslessly, and if this is not possible, it minimizes it.
Use wireless headphones
With all the impressive advantages of modern technologies, the sound quality depends not only on the audio codec used, but also on the characteristics of the hardware (headphones, speaker). Therefore, supported devices should also be implemented at the highest level, and you shouldn’t expect pure deep sound from low-power equipment with declared support for the AptX codec.
What are the abbreviations aptX, aptX HD, and LDAC?
All of these names indicate Bluetooth codecs that differ in data transfer characteristics. They have different parameters of sample rate, audio encoding depth, and bit rate, respectively, and the sound quality will be different.
AptX
Audio codec that allows audio to be transmitted via Bluetooth in 16-bit quality at a sample rate of 48 kHz to 352 kbps. The analog signal is read 48 thousand times per second, transmitted with 16 bits, which corresponds to the parameters of the CD. It is a worthy alternative to SBC with less loss of compression and better sound, cleaner and more detailed. AptX’s transfer rates are not impressive by today’s standards.
