How do you improve on arguably the best all-round true wireless earbuds on the market? Sony has gone back to the drawing board and designed a brand new pair that look nothing like their predecessors – and the result is the WF-1000XM4. Is it a brave move? Definitely. Crazy? Quite possibly.

Sony’s WF-1000X range of wireless earbuds has been a dominant force in this category over the last few years, and the last pair to emerge from its stable, the WF-1000XM3, are two-time What Hi-Fi? Award-winners.

But instead of making the odd refinement here and there, Sony’s engineers have gone to town on the WF-1000XM4 with an all-new design, a new charging case and a new audio processor. They have even found time to develop a new eartip material, which here is appearing on a pair of Sony earbuds for the first time. What could possibly go wrong?

Luckily for Sony, very little does. In fact, the WF-1000XM4 are one of the most feature-packed, user-friendly and sonically gifted pair of wireless earbuds we’ve tested.

Pricing

Unsurprisingly, the Sonys sit at the premium end of the market, coming in at £250 ($280, AU$500). That places them right in the firing line of other five-star rivals such as the Sennheiser Momentum True Wireless 2 (£279, $299, AU$499), Bose QuietComfort Earbuds (£249, $280, AU$399) and, of course, the Apple AirPods Pro, which at the time of writing range in price between £199 ($199, AU$300) and £249 ($249, AU$329).

Build

Your initial contact with the WF-1000XM4 is a surprising one. Sony has ditched the usual glossy box for recycled packaging made from a special blend of paper. This makes for a more compact box (34 per cent smaller than the WF-1000XM3’s), and one that’s plastic-free. That’s great news for the environment, though it doesn’t really give off the vibe that you’ve just bought a pair of premium noise-cancelling headphones.

Once you’ve liberated the WF-1000XM4 from their packaging, you’re greeted by a small, black charging case. It’s smaller than the case that comes with the Bose Quiet Comfort Earbuds, and positively tiny (40 per cent smaller) compared with the charging case that comes with their predecessors.

The case charges via USB-C and also introduces wireless charging to the WF-1000X range for the first time – all you need is a compatible Qi charging pad. You can even battery share with compatible smartphones and piggyback off their power supply, too.

You shouldn’t have to worry too much about the battery life. Sony’s new buds might come with a smaller case, but the XM4’s battery life is actually up compared with the XM3. You now get eight hours of play from the earbuds with noise-cancelling and Bluetooth turned on, and Sony claims the case can supply a further 16 hours of charge. That places their battery life from a single charge above all major rivals. The AirPods Pro can only manage five hours, the Sennheiser Momentum True Wireless seven hours and the Bose QuietComfort Earbuds six hours. Turn off noise-cancelling and the Sony’s life is extended to 12 hours from a single charge and 24 hours with the case. A five-minute quick charge is good for one hour of playtime, too. 

You can see the life remaining in both the buds and the case through Sony’s Headphones Connect app, which will also give you a reminder when the case drops below 30 per cent charge.

As with all wireless earbuds, battery life can vary due to a number of different factors, such as the quality of files you’re listening to, how hard the internal processor is working, and the volume you’re listening at. During our testing, we found the battery life consistently good enough to get us through a day of mixed use.

Comfort

Flip open the magnetic case and you’ll see the all-new earbud design of the WF-1000XM4. Based on a combination of customer feedback about the XM3 and research about the human ear, Sony has settled on a rounder body that sits more inside the ear opening. 

The matte finish on each earbud gives the headphones a premium feel, while the small accents around the microphone and sensor holes add a tiny splash of colour. Speaking of colour, the XM4 come in a choice of black or silver.

If you want your XM4 to double as sports or running headphones you’ll be pleased to know they boast an IPX4 rating, making them resistant to “splashing from any angle” – a big improvement on the old model.

Besides the new-look earpieces, the XM4 also have brand new eartips. Made from polyurethane, which feels like a cross between silicone and foam, Sony claims they help secure a tighter, more stable fit. The thousands of tiny bubbles in the tips are also supposed to help reduce and dissipate noise.

The only downside here is that you only get a single set of small, medium and large-sized tips to choose from. Sony says you will get years of use out of one pair, and naturally extra tips should be available to purchase if you need them.

We don’t have any major problems sliding the earbuds in and twisting them into place. If you are struggling for a seal, you can pinch the tips and slide them into your ear canal, until they expand. We find they sit snugly in your ear opening, but they are  comfortable over longer listening sessions.

To make sure you have the perfect fit, Sony has introduced a new air-tightness test, accessible through its Headphones Connect app. The app fires out a test tone and reports back on whether or not you need to make any adjustments. It’s worth trying out, especially if you feel the sound is lacking bass or there is outside noise leaking in.

In fact, we’d recommend installing the Headphones Connect app when you first connect the XM4. It gives you direct access to all the key features and functions of the earbuds so you can choose which ones to enable and disable. It also helps you get set up for listening to music in Sony’s 360 Reality Audio format from compatible streaming services such as Tidal and Deezer.

Features

The circular outer surface of each earpiece is a touchpad and, by using the Headphones Connect app, you can customise the functionality of each one. They can control volume and playback or switch between noise-cancelling and ambient sound modes through the usual combination of taps, presses and long holds – and the headphones are quick to respond to these actions. Switching between sound modes, changing volume and activating and deactivating features such as Quick Attention (which drops the volume of what you’re listening to, so you can have a quick conversation without having to remove the earbuds from your ears) happen with minimal fuss.

The Sony WF-1000XM4 borrow the Speak-to-Chat function that debuted in the WH-1000XM4 wireless headphones. This feature allows you to talk to someone while the earbuds are still in place and is triggered when you start talking. It works well, although as is the case with the over-ears, it’s only triggered a second or so after you start talking.

This slight delay can be frustrating, as can the tendency for the feature to be triggered by a cough or an impromptu karaoke session while sat at your desk. You can reduce the sensitivity of the feature, or you can turn it off completely and either use Quick Attention or remove an earbud completely (which pauses playback automatically).

On the inside of the XM4 is plenty of new technology. The earbuds feature an improved DAC and analogue amplifier and are powered by a new Integrated Processor V1. Sony claims it provides a clearer sound and even better noise-cancelling than their predecessor. The new model also gets Sony’s DSEE Extreme audio processor with Edge-AI, which we have already experienced in the WH-1000XM4 over-ear headphones, and is designed to upscale low-bitrate music files to near hi-res quality.

The 6mm driver used inside the XM4 is similar in size to the one used in the previous model, but it’s made from a new material and features a bigger magnet, which Sony claims helps improve sound quality and noise-cancelling, especially with certain low frequencies.

There’s no aptX HD support onboard, but the XM4 support Sony’s LDAC file format, which, streamed over Bluetooth from a compatible source, allows hi-res audio files up to 24-bit/96kHz to be transmitted at data rates of up to 990kbps.

Sony has also aimed to deliver clearer call quality with new features, including beam-forming and the use of a bone conduction sensor that stops the mics from picking up distracting ambient sounds while you’re talking. There’s even an automatic wind noise reduction mode which attempts to cut out swirls of noise passing through the headset and into your ears.

All of this works with Sony’s Precise Voice Pickup technology, originally introduced in the WH-1000XM4. The net effect is an impressive call quality for a pair of wireless earbuds. The technologies all combine to do a solid job of dampening down outside noise and interference, especially for the person on the other end of the line.

The general level of noise-cancelling is excellent, especially for a pair of wireless earbuds. Not everyone likes that ‘vacuum’ feeling you get when it’s turned on, but it’s extremely effective through the Sonys and you’ll struggle to find better noise cancellation at this level.

Android users will be pleased to hear the Sonys are compatible with Fast Pair so you can get up and running with minimal fuss. You receive a battery notification pop-up on your smartphone when they power up and you can even track their location down using the Google Find My Device app.

Unfortunately, iOS users don’t get any such pairing perks, but all you need to do to start pairing is open the case and take the headphones out. It’s a shame Sony hasn’t carried across the ‘Multipoint’ feature enabled on the WH-1000XM4 over-ears. This allows you to connect the headphones to two different Bluetooth devices simultaneously, which can come in handy if you’re working on a laptop but still want to be connected to your phone. Here’s hoping it can be added at a later date.

In terms of stability, we use an Apple iPhone 12 and Macbook for the bulk of our testing and find the connection to be rock solid with no dropouts, even in more built-up areas.

Sound

Before we get to the WF-1000XM4’s immense musicality and expressive dynamics, we should note the way the headphones handle bass. The quality of bass and the clarity of low frequencies is stunning. There’s such a fantastic level of detail on display that it makes rival headphones, such as the Bose QuietComfort Earbuds, sound congested in comparison.

We’re keen to hear how the earbuds handle one of our favourite bass-heavy test tracks, Massive Attack’s Angel – and we’re blown away by the confidence with which the song is dispatched. Every element of that pulsing bassline is precisely deployed and dripping in texture. It’s the clarity around the notes that really grabs you – it allows the WF-1000XM4 to communicate intricacies in the bass notes that other headphones struggle to uncover.

But it’s not a sound that purely favours low frequencies. There’s clarity across the board and a sense of rhythmic precision that allows the Sony’s to switch pace effortlessly. They sound as at home keeping up with, and succeeding in not being tripped up by, Radiohead’s 15 Step as they are dispatching the slow, deliberate swagger of Nina Simone’s Feeling Good.

Simone’s effortless vocal oozes class and sophistication, with every nuance in her delivery laid bare for the listener. Combine the emotion in her voice with the impact of the piano, percussion and wind section and the Sony’s create a captivating sound you can’t help but be swept away by.

If you were wondering whether the WF-1000XM4 would be a step up from the WF-1000XM3, we can confirm that they are. The newer model sounds more informative and uncovers more subtle detail. Bass notes are better defined and the overall sound is better balanced. Even the much-admired Sennheiser Momentum True Wireless 2 struggle to match the Sonys for tonality and refinement. 

You can hear that refinement and natural tone shine through as we listen to Ludovico Einaudi’s Experience. From the delicate, deliberate piano strokes at the start to the soaring strings at the song’s climax, the Sonys bring the individual personalities to life and mix them together like the ingredients of a fine cocktail.

Verdict

We’re quite taken by the Sony WF-1000XM4. Given all the design changes and new features in these wireless earbuds, it must have been a real challenge to get them right. But Sony has absolutely nailed it. The headphones deliver a satisfying user experience, class-leading battery life, some of the best noise-cancelling we’ve heard in this category, and absolutely stunning sound quality. Put simply, this is a new benchmark for premium true wireless earbuds.

SCORES

• Sound 5
• Comfort 5
• Build 5

MORE:

Read our guide to the best in-ear headphones

Read our Bose QuietComfort Earbuds review

Read our Sennheiser Momentum True Wireless 2 review

Read our Apple AirPods Pro review

Read our Sony WF-1000XM3 review