What is APT-X?
APT-X is an audio transmission standard whose basic algorithm was developed by Dr. Stephen Smyth in the early 1980s as part of his doctoral thesis at the Queen's University Belfast School of Electronics, Electrical Engineering and Computer Science. However, commercial use only began in the early 1990s. It enables studio-quality audio transmission in real time. It is used, for example, to record musicians or speakers in remote studios without having to incur travel expenses and travel time. It is also often used in radio broadcasting or at events for live transmission.
APT-X has established itself as a worldwide standard for real-time audio transmission, just like Music Taxi.
APT-X is offered by various manufacturers as a hardware or software solution.
APT-X is now also widely used in the so-called consumer sector, for example for transmission via Bluetooth.
For good quality transmission, an ISDN line with at least 2 channels is required.
When using these codecs, the audio signal is compressed similar to the mp3 format. The MPEG-1 Layer 2 standard with 64mbps or 128mps data rate with 48kHz sampling rate is often used. But other compression formats are also possible, but not so common.
The so-called "Enhanced APT-X" was introduced as an extended codec, which allows a higher compression rate while maintaining the same quality.
Conversely, "Enhanced APT-X" can be used to achieve higher audio quality at the same data rate.
As an alternative to APT-X, the Music Taxi In order to ensure reliable operation, a so-called "real" ISDN is required. Emulated ISDN on Voice over IP (VoIP) basis offered for normal telephone operation is not sufficient and therefore does not guarantee reliable and trouble-free transmission for technical reasons.
In Germany, the ISDN network is currently being successively switched off and replaced by VoIP. You can now operate your ISDN devices via the router (if it has an ISDN output). However, this does not work properly for real-time audio transmission.
For this reason, pure VoIP solutions are increasingly being used. In Germany at present SessionLinkPro, Source-Connect and ipDTL relatively popular (status 2018).
We are also affected by the ISDN shutdown since March 2018 and work as a VoIP solution primarily with Source Connect.
Why do I need an APT-X?
What ATP-X and other audio transmissions are good for you can find out here.
APT-X - Wordvoice GmbH