Detailed Information

Originally developed in the 1980's at Queen's University Belfast, the aptX™ coding algorithm has been the secret weapon of the professional audio and film industries because of its ability to deliver CD-like quality audio over low-power Bluetooth® wireless connections.

When sound waves are transmitted over Bluetooth® as digital audio, they are first compressed to reduce their size using a coding method called "SBC", which stands for Low Complexity Sub Band Coding. the compression process takes a series of snapshots of the audio at specific moments in time known as "samples" and, with enough samples, a Bluetooth® receiver can convert them back into a full sound wave.

Since Bluetooth® is limited by a maximum available bandwidth and because SBC was designed to use as little processing power as possible, some of the data is discarded using a process called "psychoacoustic modeling". Psychoacoustic modeling removes portions of data that theoretically cannot be heard to reduce file size. The result is less than accurate audio reproduction.

To overcome the low-power constraints of SBC and the bandwidth limits of Bluetooth® audio, the patented aptX™ coding algorithm applies a different approach at bit rate reduction. By using a method of "time domain ADPCM" to encode the audio, aptX™ uses fewer bits per sample, so the files are smaller and arrive transparently and intact. The result is full bandwidth audio reproduction that requires less energy and size for transmitting.

* Qualcomm aptX is a product of Qualcomm Technologies, Inc. and/or its subsidiaries. Qualcomm is a trademark of Qualcomm Incorporated, registered in the United States and other countries. aptX is a trademark of Qualcomm Technologies International, Ltd., registered in the United States and other countries. Any use of such marks by JL Audio is under license.