If you already had Bluetooth speakers before Christmas or have just purchased them, you may have already noticed that the sound transmitted wirelessly to them is often less well reproduced than when you connect a source in wired mode (depending on compatibility).
This loss of quality comes from two major factors: the digital / analog converter and the audio compression.
Sending an MP3 file from a smartphone to a Bluetooth speaker is a bit like playing yoyo with compression, making a photocopy of a photocopy … MP3 is a compressed digital format, which must be decompressed and converted to l analog to be powered by the speakers, in wired mode.
In a wireless connection, the sound is decompressed, then compressed again by the smartphone to be sent to the speaker which converts it from digital to analog to reproduce the sound. This therefore involves two phases of conversion, including compression which results in a loss of quality.
Bluetooth technology has not been designed to transfer high quality wireless music. At the outset, it was a question of making it possible to offer wireless headsets and basic accessories, but nothing really suited to music lovers.
Gradually, new protocols appeared, and the manufacturers reoriented their products towards devices increasingly cut for the sound. The switch has really been made since the creation of the aptX codec which aims to replace the SBC (Low Complexity Subband Coding) too limited. Unfortunately, this codec is not free, and brands have to put their hands in their pocket to integrate it into their products, so not all of them offer it, although it is more likely to limit losses in quality in compression. .
Remains that currently, comparing aptX with SBC allows, of course, to judge a certain improvement in favor of the first, but we are still far from equaling the quality of sound allowed by a wired connection. Unless we develop new technologies, our mastery of Bluetooth currently does not allow us to offer wireless Hi-Fi devices worthy of the name.
When can we recommend switching to a Bluetooth speaker or headset? If the nomadic aspect takes precedence over the rest, that listening is done in a noisy environment, that the quality is not essential or that more generally, the files read are of average quality, the Bluetooth terminals will do the trick ( even if they are not all equivalent.). If on the contrary, it is a question of enjoying high quality music in a calm environment, no need to break your piggy bank in Bluetooth equipment, even for those overpriced sold by the great designers or sound masters, the mode wireless is currently unable to offer anything worthwhile for real music lovers.