Therefore, the Bluetooth connection could only broadcast, up to not so long ago, lossy compressed files such as MP3 and AAC. Things have actually changed a few years ago, when some devices compatible with Bluetooth have integrated an aptX decoding chip, a highly advanced compression process, with (small) losses, whose manufacturer, CSR (Cambridge Silicon Radio)—which has since been bought out by Qualcomm—insisted on the fact that the aptX codec allowed for a sound reproduction close to CD despite a 4/1 compression ratio, thus reducing the starting output of 1411 kbps to an output compatible with a Bluetooth connection.
In fact, the few devices which could decode aptX that we were able to listen to offered a sound reproduction that was indeed really close to the one we would have gotten by playing the CD or the uncompressed 16-Bit/44.1 kHz audio file.
We would also like to insist on the fact that, in order to benefit from the advantages provided by the aptX in terms of sound quality with a Bluetooth connection, it is imperative, just like with any codec, that the transmitter be compatible with aptX to do the encoding, and the receiver also be so that it can do the decoding.
You can discover all the products compatible with aptX (mobile phones, speakers, wireless headphones, etc.), displayed randomly, by brand or product type, by following this link.
There are also USB sticks compatible with aptX that you can use with the CSR Harmony software (which handles aptX) and that can be used with a computer.
Some time ago, a new version of the aptX appeared, called aptX HD and compatible with Hi-Res audio up to 24-Bit/48 kHz.
We had the opportunity to discover the qualities of the aptX HD during the recent testing ground devoted to the Bluewave Get aptX HD Bluetooth receiver, whose sound results impressed us greatly.
We would also like to point out once again that the transmitter and the receiver must both be compatible with aptX HD (this information is exchanged during the pairing of the devices) if you want to benefit from the encoding of Hi-Res files during their transmission and from the decoding during their reception.
This is the case, for example, between the Sony Xperia XZ1 smartphone and the Bluetooth Get receiver, where you can notice that the aptX HD encoding is indeed activated on the Sony. If any of these devices aren’t compatible with aptX HD, the transmitter should display the encoding compatible with the receiver.
You can discover all the products compatible with aptX HD (mobile phones, speakers, wireless headphones, etc.), displayed randomly, by brand or product type, by following this link.
Therefore, these aptX and aptX HD Bluetooth connections offer very interesting alternative to Wi-Fi systems by providing high-quality sound reproduction both with files stored on a smartphone or while streaming Qobuz.