Chip manufacturer Qualcomm has today announced that it has tweaked its (lossy) aptX Adaptive codec so that its Snapdragon Sound platform can deliver CD-quality (16bit/44.1kHz) audio over Bluetooth and losslessly — no data discarded. Lossless transmission has long been the holy grail of audio enthusiasts wanting better technical performance from Bluetooth streams.
From Qualcomm’s press release: “Lossless audio means mathematically bit-for-bit exact, with no loss of the audio file and up to now the necessary bit rate to deliver this over Bluetooth has not been available.”
How does aptX Lossless work? We go back to the press release for the answer: “aptX Adaptive works in conjunction with Qualcomm Bluetooth High Speed Link technology to help deliver the required sustainable data throughput. Designed to work seamlessly together, these technologies deliver rates beyond 1Mbit/s yet smoothly scale down to 140kbits/s in congested RF environments to minimize any audio dropouts or glitches for a consistent and reliable listening experience.”
In other words, in an RF-free environment, CD-quality audio should flow just nicely via a losslessy-compressed 1Mbit/s Bluetooth connection between smartphone and headphone, but if you happen to walk into a more RF-congested area, the music will keep playing but at a lower bitrate (and with lossy compression). The more RF, the lower the bitrate and the greater the lossy compression.
What about hi-res audio? aptX Lossless users will also have the option to switch the codec into a second mode that handles hi-res audio streams, albeit with lossy compression — data is discarded.
The bad news for Apple users is that iPhones and iPads don’t currently support Qualcomm’s family of aptX codecs. Unless that changes – or if Apple introduces its own lossless Bluetooth audio codec – lossless CD-quality streaming will remain the preserve of Android devices. Most modern flagship ‘Droids support aptX and its variants but it’s not yet clear if we’ll need to buy a new Android device in order to put aptX Lossless support in our pocket.
What is clear is that we’ll need a new pair of Bluetooth headphones. Qualcomm expects headphone manufacturers to begin shipping aptX Lossless-supporting headphones in early 2022.
With Spotify about to join Apple (and Tidal, Deezer and Qobuz) in the CD-quality streaming space, the timing of this announcement could not be keener.
And Qualcomm’s aptX Codec should also make wired headphone manufacturers more than a little nervous. We might soon see Bluetooth headphones reframed as digitally active loudspeakers for the ears. They already give us the benefits of DSP: ANC, hearing profile matching and amplifiers tuned precisely to their drivers and today Qualcomm kicked the biggest downside – lossy compression – into touch.
Further information: Qualcomm Press Room