The Sony WF-1000XM5 flagship earbuds are ranked top of our best wireless earbuds right now, so there's little doubt that they are capable of outstanding performance. As I said in my review, they really are the best-sounding wireless earbuds I've heard, even if the $299 (£259 / AU$499) feels steep in today's economic climate.
If you're listening to Sony's WF-1000XM5 earbuds via an iPhone, then you're listening to them wrong.
Even so, there's no doubt in my mind that Sony's newest earbuds offer outstanding levels of performance when listening via a high-quality media player such as the Fiio M15S portable music player or the Sony Xperia 1 IV, which —along with several of the best Android phones — support LDAC. Unfortunately though, if you're listening to Sony's WF-1000XM5 earbuds wirelessly connected to an iPhone, then you're listening to them wrong. Let me explain.
Sony WF-1000XM5: Extensive listening
As I mentioned in my Sony WF-1000XM5 review, I was lucky enough to be one of the first audio experts in the world to experience Sony's next-gen flagship wireless earbuds. Despite some initial difficulties regarding the troublesome fit thanks to the smaller earbud design that meant I had to step up an ear tip size to get the optimal fit test to work for me, and finicky 360 Reality Audio personalization issues, Sony's WF-1000XM5 wireless noise-canceling earbuds have been my go-to earbuds ever since I got my hands on them. Even after further testing and countless hours of extended listening, I remain mightily impressed. But they're not for everyone.
As with all of the company's headphones, they come with an exceptional user experience via the amazingly comprehensive and well thought-out Sony Headphones Connect app. There's a catch though to unleashing their best sound, which comes down to the type of Bluetooth codec support that your playback device is using. It sounds rather dull, I know, but codecs and the rate at which they transfer audio data is one of the biggest determining factors when assessing sound quality.
In my review, I made it clear I was experiencing the Sony WF-1000XM5 wireless noise-canceling earbuds via an LDAC-capable Sony Xperia 1 IV smartphone supplied by Sony, which clearly shows off their full sound quality potential. The new Sonys have Bluetooth version 5.3, which improves efficiency and provides more stable connectivity, and with LDAC mode enabled on the Xperia smartphone, the sound quality from Sony's latest flagship earbuds blew me away. Here's why.
What's the difference between LDAC and AAC?
For some perspective on the amount of data being transferred in kbps (kilobits per second), Sony's LDAC offers a maximum wireless streaming bitrate of up to 990kbps over Bluetooth connectivity, whereas Apple's AAC (the highest audio codec supported by iPhone) maxes out at 320kbps over Bluetooth.
If you think of audio quality in terms of the amount of data being transferred between devices per second, then you can see that AAC is compromised. That being said, AAC is more sophisticated than the SBC Bluetooth codec and does have a way of making Bluetooth sound spectacular on plenty of wireless audio products including Apple's made for iPhone AirPods Pro 2 wireless earbuds and AirPods Max wireless headphones of course.
Sony WF-1000XM5: Sound quality with LDAC
The Sony XM5's ability to extract more information than most earbuds I've heard is truly outstanding. Extra detail levels that can easily get missed by lesser earbuds were far more noticeable. It's not that the frequency range is boosted in any particular area, I believe they are able to get to the heart of whatever you're playing in an effortless and musical manner mostly because of the greater amount of audio data that's being transferred.
The new dynamic driver also has a part to play of course, and uses a combination of materials to handle different parts of the frequency range that makes nuanced instruments and vocals sound natural and convincingly realistic, putting you in a front row seat for whatever you're listening to.
Sony WF-1000XM5: Sound quality with iPhone AAC
Listening to exactly the same content on the Sony WF-1000XM5 connected to my iPhone 12 Pro from my Tidal HiFi playlist wasn't quite the same once I'd heard the full glory of their audio performance via an LDAC-enabled device. If anything the new WF-1000XM5 don't sound much of a step up from the Sony WF-1000XM4 last-gen wireless earbuds, partly because I was more easily able to hear the shortcomings of the AAC codec being used on my iPhone. Naughty Sony!
I'm not saying the XM5s sound bad on my iPhone by any stretch. Just that the sound isn't nearly as detailed in terms of being able to follow different instrument parts and layers that make up any music mix. By comparison, the Bluetooth audio from my iPhone sounds less refined, making the overall experience feel less immersive and engaging as a result.
Buy the Sony WF-1000XM5 earbuds if your playback device supports LDAC
When testing any audio product, I always use the highest-quality audio the device can handle. This enables me to get a sense of the full potential of a product's capabilities before testing out performance with lower-quality options.
Although I do think that it's a little disappointing that Sony hasn't managed to make its newest flagship earbuds sound just as great when connected to an iPhone using AAC, there may be some sound tuning improvements that come for AAC connections in a future Headphones Connect app firmware update.
Sony has clearly designed the WF-1000XM5 earbuds to deliver their best performance with LDAC, which to me sounds exceptional. By using a new dynamic speaker driver Sony has managed to highlight the audio quality differences between codecs, making the drop in audio quality when using lower kbps transfer rates more apparent. To my mind, if there was ever a reason to upgrade to a playback device that has support for LDAC over Bluetooth, then the Sony WF-1000XM5 are it. With the right playback, they're the closest thing to audiophile listening I've heard from a pair of wireless earbuds.