Hands-on with AptX Lossless, the new technology that promises CD-quality audio over Bluetooth

CD quality music is still the benchmark for decent audio; it’s not quite hi-res, but it’s noticeably better than the lossy, compressed music found on Spotify and your old MP3 library. But really listening to uncompressed CD-quality music on a phone can still be tricky when convenience is also important. The source material has to be of adequate quality first and foremost, and once it gets to your phone you need a way to get it to your headphones without that extra audio quality being compressed away. Easy enough in an age of wired headphones, but a little harder with wireless earbuds.

Qualcomm’s new AptX Lossless standard should finally close the gap between the fidelity of CD-quality audio and the imperfect compression of Bluetooth. Getting access is still harder than it should be, but after spending an afternoon comparing it to its predecessor, the difference in quality is huge.

It has taken a while for hardware to support the new standard to hit the market since it was first announced over a year ago. In June, audio company Nura announced the first pair of earbuds with AptX Lossless support, but only a handful of smartphones on the market are actually compatible with the new codec. However, that is finally starting to change with phones like the Asus Zenfone 9 that come with built-in AptX Lossless support. Nura gave me a sample of the phone to properly test the new earbuds.

The NuraTrue Pro itself is a pretty typical looking set of true wireless earbuds. They offer 8 hours of charging from the earbuds themselves, an additional 24 hours from the case, and come with four microphones on each earbud to handle calls and noise cancellation. These microphones are also responsible for Nura’s signature personalized sound technology, which she says measures your ears to optimize the audio for them. Nura is currently funding the earplugs through a Kickstarter campaignstating that the earbuds are expected to launch in the fourth quarter of this year.

Crucially, Nura’s wireless buttons support Qualcomm’s AptX Lossless standard. The chip manufacturer says the new Bluetooth technology is capable of transmitting CD-quality audio (16-bit / 44.1 kHz), without any loss of detail (hence “Lossless”). That’s in contrast to its previous highest-resolution codec, AptX HD, which is still heavily compressed despite claims to transmit audio comparable to 24-bit/48kHz or even 24-bit/96kHz.

Despite its lossless branding, AptX Lossless is not whole compression free. There’s still some compression at work here to bring down 1.4Mbps CD quality audio Bit rate of 1 Mbps that AptX Lossless is capable of to send. But the difference here is that the compression used should not result in loss of data, and is “bit-by-bit” exact. “After it’s decompressed, it’s exactly the same as the original,” says Nura CEO Luke Campbell, “think of a ZIP file. It gets smaller, but it’s exactly what it was when it came out.”

For my tests, I used Lossless audio streaming from Apple Music. I verified that I had all audio quality settings set to the highest available option and checked the specific audio resolutions listed for each track. In some cases, these tracks were even higher resolution than the CD-quality audio that AptX Lossless can transmit, but that shouldn’t matter for the purposes of my comparative testing.

In theory, the test should be relatively easy, but Qualcomm’s software doesn’t make it particularly easy to see when you’re streaming through AptX Lossless. The new codec is technically an extension of AptX Adaptive, the company’s pre-existing codec that dynamically scales the bitrate of your audio depending on your environment. So when I connected the NuraTrue Pro earbuds to the Asus Zenfone 9, a Qualcomm tooltip popped up to note that I was connected via “Snapdragon Sound” and “AptX Adaptive” without specifically mentioning lossless. But between Nura’s confirmation, listening to me in a quiet location, and Qualcomm’s AptX site specifically stating that the device supports AptX LosslessI’m sure I’m hearing lossless audio.

Neither Qualcomm’s nor Android’s software offers you an easy way to switch between different versions of AptX to run an AB test. Instead, at Campbell’s suggestion, I took advantage of the NuraTrue Pro’s multipoint connectivity to directly compare listening from an AptX Lossless-compatible handset (the Asus Zenfone 9) to a regular AptX HD-compatible phone ( the Honor 70). With this setup, I could have Apple Music streaming losslessly to both phones and then have the NuraTrue Pro plugged into both phones in turn to see what difference in sound quality I could notice.

To my ears, AptX Lossless seemed to have a small, but noticeable, impact on sound quality. It wasn’t a night and day difference (turns out Bluetooth audio compression has gotten really damn good in recent years), but it was the kind of little differences that are fun to sort out in familiar songs. A little extra brightness here, a little extra depth there.

As for Eagles’ “Hotel California” (which Apple Music reports streaming at a high resolution of 24-bit/192kHz), the benefits of Lossless seemed most apparent in the high frequencies. The plucked guitar notes in the song’s intro had more clarity and brilliance with the Bluetooth quality boosted to lossless, and every instrument in the song felt more present and audible. It never sounded poor when listening on the Honor 70, but the Zenfone 9 had just that little bit of extra detail.

That’s not to say the differences were great, and it’s clear that the quality of the track’s mastery plays a big role. I tried listening to Nirvana’s “Lithium” (24-bit / 44.1 kHz, a smaller step above CD quality) and it was much harder to tell the difference between the two audio codecs. Perhaps Cobain’s opening guitar riff and vocals would have had a little more room around him with AptX Lossless turned on, but I doubt I’d be able to tell the difference in a blind test. The differences were a little more apparent in a busier trick like “Territorial Pissings,” which sounded muddier on the non-AptX Lossless device, but the difference was small.

Then I tried some techno with Vessels’ “Elliptic” (16-bit / 44.1kHz, aka CD quality). While the non-AptX Lossless handset felt like it was a bit overwhelmed by the track’s booming bass, the Zenfone 9 gave it a much more balanced sound, with a higher pitched tone that sounded much more prominent in the mix and given more space. to breathe . It almost felt like AptX Lossless was helping to remove the song from a sea of ​​bass.

Finally, I listened to “Maps” by the Yeah Yeah Yeahs (24-bit / 44.1 kHz). Here, each of the instruments felt more three-dimensional when streamed via AptX Lossless. They sounded less like parts of a song, and more like physical instruments recorded in a studio.

In any case, I’d be hard pressed to call AptX Lossless’s improvements transformative. But it felt like it added that little bit of extra detail that I often didn’t realize I was missing. It’s almost like that moment when you start streaming a video, and it looks good until the moment it buffers well and comes into focus. It didn’t look “bad” before, but once you see it in its highest quality, you become aware of its shortcomings.

There are always many variables when testing audio equipment and I wouldn’t want to draw any firm conclusions about AptX Lossless from the time I’ve spent with the NuraTrue Pro. For example, the codec could have a more pronounced impact on more expensive and/or over-ear headphones or on other tracks. But based on my listening experience, the impact AptX Lossless had was subtle enough that I personally wouldn’t rush to buy a new pair of headphones based on the audio codec alone (sorry Nura), and I Surely wouldn’t buy a new phone to get support. Even given the choice between two headphones, I’d probably choose based on subjective audio quality rather than which model has the more advanced audio codec on its spec sheet.

Ideally, AptX Lossless would just become one of those audio features supported by enough smartphones and headphones that you take advantage of without realizing it. But while AptX is widely supported on countless wireless headphones and Android phones, it remained absent on iPhones and AirPods. Lossless Bluetooth streaming can be a great upgrade for audiophiles who hate listening to lossy audio, but its subtle benefits can be a harder sell for more regular listeners.

Photography by Jon Porter / The Verge