As any audiophile can tell you, Bluetooth audio technology is all about compression. It's much better compression than it was in the early days -- when Bluetooth speakers and headphones were unforgivably tinny and thin -- but in order to go wireless, Bluetooth technology was all about squeezing as much sound into as little bandwidth as possible, quality be damned. But that may finally be changing: Qualcomm says it's figured out a way to deliver lossless audio over Bluetooth, yielding quality that should be indistinguishable from uncompressed sources. And it's calling it aptX Lossless, the next generation of Qualcomm's proprietary audio format.
Taking a "systems level approach," was the key, the company says, as it's "optimized a number of core wireless connectivity and audio technologies, including aptX Adaptive, which work together to auto detect and scale-up and are designed to deliver CD lossless audio when a user is listening to a lossless music file and the RF conditions are suitable."
So, yes, there are a few caveats, and you'll need new hardware to get the full aptX Lossless experience -- that goes for the device you're streaming from (a phone, for instance), as well as your listening device, typically a pair of headphones. Qualcomm says devices that support aptX Lossless are expected to be available in early 2022.
"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," said James Chapman, Qualcomm's vice president and general manage. "With many leading music streaming services now offering extensive lossless music libraries, and consumer demand for lossless audio growing, we're pleased to announce this new support for CD lossless audio streaming for Bluetooth earbuds and headsets which we plan to make available to customers later this year."
By customers Chapman doesn't mean you and me, but rather tech companies that will implement Qulacomm's chips in future products.
Lossless audio: Still a niche, but growing
The big issue with lossless audio over Bluetooth is that Bluetooth simply isn't designed to handle lossless audio -- it just doesn't have the bandwidth. If you have a collection of lossless audio files, you know how big they can get and Bluetooth just isn't equipped to deal with them. So the solution is to go with proprietary Bluetooth audio codecs using compression technology that under the right conditions can get you to near lossless audio -- or something that sounds very close to as good as lossless audio.
Read more: Best true-wireless earbuds for 2021
In terms of the pecking order for Bluetooth codecs, Sony's LDAC codec, with some caveats, is generally viewed as the best right now, Qualcomm's aptX HD is a small step below that. And then you have AAC right behind them.
I can get really granular here and talk about 16-bit vs. 24-bit depths and audio resolutions but one of the problems when you get into so-called high resolution wireless audio codecs is that you need to have the right devices to support them. Apple's iOS devices like the iPhone and iPad only support AAC -- and for most people it sounds just fine. LDAC and aptX only work with Android devices and certain dedicated music players. And then of course you need a headphone or speaker that supports those codecs -- and it better be a really good headphone or speaker or it won't matter.
On top of that, if you're using a streaming service, you need one like Qobuz, Amazon Music or Tidal that offer high fidelity streaming for Android devices. So there are a lot of variables and it isn't always clear whether you're listening to something at the optimal quality level. While Sony's LDAC can support wireless streaming with a bitrate of up to 990 kbps, you can get dropouts, at which point the bit rate gets bumped down. That's why some people say aptX is more reliable even if it can't stream at as high a bit rate. And reliability certainly is a factor because even if your audio sounds great, having it glitch is a serious downer. And while Bluetooth connectivity continues to improve, you can always run into some interference issues or you can only wander so far away from the device you're streaming from.
Qualcomm says that to help deliver CD lossless audio quality reliably over Bluetooth wireless technology, 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," the company says.
Qualcomm is offering the media demos of aptX Lossless at an event in New York today and it will interesting to see what devices the company is using for the demos and what differences in audio quality will be discernible. Until now, to get the best audio experience, the wired listening route remains the best option. And while Apple introduced lossless audio in Apple Music earlier this year, it received some criticism because none of its wireless headphones were compatible for lossless music listening. This includes wired mode in the case of the AirPods Max, currently discounted to $489 at Amazon).
I'll update this post after I get some hands-on listening with aptX Lossless, but for now here are its key specs:
- Supports 44.1kHz, 16-bit CD lossless audio quality
- Designed to scale-up to CD lossless audio based on Bluetooth link quality
- User can select between CD lossless audio 44.1kHz and 24-bit 96kHz lossy
- Auto-detects to enable CD lossless audio when the source is lossless audio
- Mathematically bit-for-bit exact
- Bit-rate : ~1Mbps