Let’s face it. While Bluetooth audio streaming is a neat convenience, even expensive solutions are inferior in terms of audio quality to their wired counterparts. It isn’t the engineering that is lacking, but rather, Bluetooth technology isn’t primed for audiophile-grade tastes. If anything in the audio delivery suggests “compression”, it is an instant turn-off – which unfortunately is how Bluetooth streaming works. The aptX audio codec (developed by Qualcomm) is the means for the wireless transfer, which has to digitally reduce the data in order to send it.
But Qualcomm refuses to leave it at that. It has been working on an update to the widely adopted audio codec, dubbed aptX HD. While the general operation of the technology is the same, aptX HD opens the stream up to 24-bit audio quality (from 16-bit in aptX).
[blockquote author=”Qualcomm”]As well as accepting a 24-bit audio input, 24-bit audio resolution is maintained by using an extra two bits in each of the four sub-bands of processing. This results in lower signal-to-noise ratio (the signal strength signal strength relative to background noise) through the encode/decode cycle and less distortion, making aptX HD ideal for use as part of a high-resolution audio solution.[/blockquote]
No, this won’t solve the compression limitation with Bluetooth streaming, but Qualcomm is hoping that the net amount of audio data reaching your DAC (digital-to-analog converter) will be significantly larger. Bear in mind that you may need a good pair of Bluetooth headphones (with a competent on-board DAC) to notice a difference.
Qualcomm says that aptX HD is now available in the CSR8675 Bluetooth audio SoC platform, which supports the 24-bit resolution all-around.
The aptX HD source has begun making its way to Android devices, but stay tuned for the adoption of the new audio codec to grow over the year. Maybe that’ll give more Bluetooth headsets a chance to catch up as well.