The new earbuds see the debut of a brand new Integrated Processor V1, while the earbuds also include the company's DSEE Extreme audio engine which is also used by the Sony WH-1000XM4 over-ear headphones. A new 6mm driver has been designed for the WF-1000XM4 which Sony claims improves bass performance compared to the current WF-1000XM3.
The XM4s are also the first wireless Sony earbuds to support LDAC, which means they can support hi-res audio streams up to 32-bit/96kHz over Bluetooth at up to 990kbps. From a compatible source, of course.
Thanks to a combination of that Integrated Processor V1 and an increase in magnet volume for its new driver, Sony is claiming the "industry's highest level of noise cancellation," all while using less power than the XM3.
Even the earbud tips have been redesigned to better block outside sound. They're made from a unique polyurethane foam material that compresses down to fit in your ear and then expands to fill any gaps.
Lack of water resistance was one of the biggest criticisms of the current XM3, but the XM4 are IPX4 rated, meaning they should survive splashes and sweating. The Sony Headphones Connect app now has a tutorial to help you get the best fit, and Automatic Wind Noise Reduction makes its debut to help keep sound clear even during a gale.
Besides the new tech, the WF-1000XM4 share some features with other current Sony headphones. They have the same Speak-to-Chat feature as the WH-1000XM4. This recognises when you're speaking, and simultaneously pauses the music and lets in outside sounds, so you can have a conversation without taking the earbuds out of your ears.
Quick Attention featured on the WF-1000XM3 and it makes a return here too, allowing outside sounds in at the press and hold of a touch-sensitive button.
And, Adaptive Sound Control also makes the move over from Sony's previous-generation headphones. The WF-1000XM4 learn to recognise where you are and what you're doing and can adjust the sound accordingly. The inclusion of a bone conduction sensor and beam-forming technology promises to make handsfree calls even better on the new headphones.
The biggest news, though its that Sony has redesigned the earbuds from the ground up, opting for a rounder, more compact design compared to the 'squashed pill' look of the WF-1000XM3. They're 10 per cent smaller than their predecessors, and the carry case is 40 per cent smaller. Despite these smaller dimensions, Sony has squeezed some extra battery life out of them. The buds now last eight hours on a single charge (up from six for the WF-1000XM3). Add another two full charges from the case, and you should get 24 hours of use before needing a plug socket – that matches the Apple AirPods (2019).
Switch off noise-cancelling and that eight hours jumps to 12, and the 16 hours from the case increases to 24, making for a total of 36 hours before needing to juice up from the mains. A five-minute charge gives you an hour of run time, while the app will tell you when the carry case drops below a 30 per cent charge.
You can also charge up the carry case wirelessly from a compatible smartphone like the Sony Xperia 1 III by placing them on the handset's back with the battery share feature activated.
Alexa and Google Assistant voice assistants are supported as you would expect, and they also play nice with Google's Fast Pair feature for fuss-free pairing with an Android device. More of a Microsoft fan? Its Swift Pair feature is also supported, for quick pairing to Windows 10 devices.
And the price? £250 / $280 / AU$450. The Sony WF-1000XM4 are available for pre-order now and stock will follow shortly. That's a little more than the XM3 (which we've been told will continue), but if they live up to Sony's billing, they could more than justify the price tag.
Read our Sony WF-1000XM4 review
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