SONY WF-1000XM4 true wireless
Sony makes significant advances with its new true wireless in-ears, maintaining their lead.
Do Sony’s updated buds maintain their lead?
There’s no doubting Sony’s modern pedigree with noise-cancelling headphones. Its WF-1000X over-ears and WH-1000X in-ear product lines have consistently dominated their classes. And with this WF-1000XM4 release, the latest of the true wireless in-ears, Sony has upped the ante once more, introducing an entirely new ANC (Active Noise Cancelling) processing chip, along with a redesigned earbud. The results are stunning, if somewhat pricey.
Design
As with past 1000X launches, the WF-1000XM4 is available either in black or ‘platinum silver’ — both classily understated with brassy, metallic trim that subtle counterpoints the uniform matte tone of the plastic. This trim is most prominent in the cylindrical microphone housing protruding from each earbud, and is seen again on the top of the buds (surrounding yet another microphone slot) and in the small ‘Sony’ branding on their front.
While Sony says the new buds are only 10% smaller than their predecessors, the new shape makes them look and feel considerably more compact, aligning with the trend for shrinking bud sizes. The move from a bulbous elongated design to something more circular shifts the centre of gravity closer to the ear canal, providing many advantages, appearance among them, but also security and comfort. The earbuds are less likely to get nudged out of place or to fall loose due to their own weight or a sudden movement, and they are also significantly more comfortable than the previous M3, delivering less fatigue from long listening sessions and a less obvious presence during shorter periods.
Another aspect of the WF-1000XM4 redesign is its ‘Noise Isolation’ earbud tips, of which three different sizes are included in the box. These tips are similar in effect and style to Comply foam tips, but offer a slightly different surface. We found them incredibly comfortable, more forgiving with their fit due to their squishy nature, easy to achieve an adequate seal for optimal audio.
It’s worth noting that this is the first time we’ve seen an in-ear product ship without the option of silicon tips (foam is more usually an alternative); we like the foam, as noted, though they’re unlikely to match the durability of silicon. Entirely laudable, however, is the plastic-free lowtoxicity packaging: 99% of the paper is recycled and sustainable material.
While the M3’s charging case had a flat-top lid and rather deep design, this successor’s case is considerably more elegant, with delicate curves and balance
coupled with a 40% reduction in size, making a significantly more pocketable item.
Features
The charging case now supports Qi wireless charging (one possible justification for the $50 price increase over last year’s model), compatible with regular charging mats or phones and other devices that have a battery share function.
With ANC enabled, the WF-1000XM4 buds last eight hours on a single charge — impressive for such advanced and compact tech — and the case holds an extra 16 hours. This solid total of 24 hours can be credited to optimisations in efficient ANC in the new Integrated Processor V1, and indeed without ANC this battery life extends to 36 hours total: 12 in the buds and an extra 24 in the case. Sony claims that a five-minute quick charge is enough to give you an hour’s playback.
One of the more obvious shortcomings of the M3 was its complete lack of waterproofing, but the M4 features an IPX4 rating. While plenty of the competition features IPX7 or 8, the IPX4 guards against “water splashing against the enclosure from any direction”. Hence while the M3 buds were aimed at inactive wearers — commuters, workers, casual listeners — the IPX4 rating and more secure fit here make the new model viable for a workout or a stroll in inclement weather, so significantly more ‘everyday’ than their predecessors.
Sony has brought back its ‘Speak to Chat’ feature, first seen with the WH-1000XM4 over-ear headphones, pausing the music and enabling Ambient Sound mode when the buds detect your voice. We found this feature to be a great idea when working as intended (it quickly engages when you want to have a conversation), but also found it triggering accidentally sometimes in response to laughter or singing along.
Another feature arriving from the over-ear counterpart is the proximity sensor, automatically playing and pausing your music when the buds have detected that they are in or out of your ears. This worked exactly as it should and is incredibly useful.
In order to interact with the WF-1000XM4 there’s a capacitive touch control on each bud, allowing for the usual single, double and triple taps, as well as the tap-and-hold to activate different functions. We found these interactions to be about as reliable as they were on the M3, which is to say that they rarely misbehave. You can customise these to an extent within Sony’s companion Headphones app, but the depth of this is reduced to choosing what function you’d like each bud to handle — playback, volume, ANC, voice assistant, or nothing.
Within this app, you can also set many of the features discussed in this review, including an intensity level for Ambient Sound mode (from 1 to 20), equaliser presets, audio codecs, auto-pausing and much more. There’s even a walkthrough and test for determining the right size of eartip for your ear canal, a welcome addition and one we haven’t seen in any other buds.
For voice calls, the Sonys use a combo of its external microphones, beam-forming and bone-conduction sensors to improve the quality and clarity of your voice, while you also hear others more clearly due to the ANC.
ANC
For noise cancelling, Sony has replaced its powerful QN1e chipset found in the M3 with the new Integrated Processor V1, bringing a host of improvements to power efficiency, audio quality, Bluetooth stability, and noise cancellation.
This chipset improves on its predecessor’s ANC performance and does so in a more power-efficient manner. The V1 chip works with a pair of microphones per earbud, one feeding forward from outside and one feeding back from inside. In use, we found that heavy traffic and even regular construction sounds were rendered all but inaudible, while even the irregular strikes of a concrete breaker was severely softened.
Part of this prowess comes from a 20% increase in the magnet size within the WF-1000XM4’s drivers. This bigger magnet allows the buds to produce and hence cancel even lower frequencies than before, so rumbling trains, and deep construction drones should be less invasive now. Even a walk on a windy afternoon didn’t spoil our noise-cancelling bliss — a common shortfall of ANC devices, that tell-tale whoosh and crackle dampened when we activated Sony’s ‘Automatic Wind Noise Reduction’ feature.
‘Ambient Sound’ and ‘Quick Attention’ modes also make a comeback, the former allowing you to hear external sound using the external mikes, and the latter doing the same but on a momentary basis, along with pausing playback. We’d rate the Ambient mode the best of any we’ve tried to date, achieving a nicely organic experience rather than the ‘super-hearing’ effect that often comes from running external microphones straight into your ears.
Audio quality
All these features would, of course, be for nought if the WF-1000XM4s sound like rubbish. They don’t, thankfully; indeed these buds offer the best audio quality we’ve yet experienced in true wireless headphones. From its 6mm drivers, Sony’s earbuds achieve a rich and pleasant sound with a slightly warm skew — the slightly rolled-off upper frequencies save it from any threat of tinny treble, while the bass is forward but far from overbearing; indeed the default bass response is slightly less pronounced than its predecessor, perhaps a side-effect of their foam rather than silicon eartips.
If this frequency profile isn’t to your liking, Sony’s Headphones app offers a number of preset EQ profiles along with two presets to craft your own, using five-band adjustment and a Clear Bass feature. We found the default profile to be perfectly balanced for almost every situation and stuck to it much of the time, but the tweaking works well.
The clarity, separation and sense of space offered by the WF-1000XM4 are worth commending as well, and with no sign of distortion or flattening even at higher volumes; each instrument and musical component shines through as intended. Listening to Sharon Van Etten’s Jupiter 4,
the ambient synth washes, whines and warbles of the brooding intro were kept clear and distinct rather than blending into a wash of noise, while the tension and drama of the ascent to the ultimate chorus were made palpable as each element is heard soaring along with the punch of Sharon’s voice.
The pulse driving People, I’ve Been Sad by Christine and the Queens was made all the more punchy by these buds’ precise delivery, the drum machine landing perfectly in step with the vocal refrain in the chorus, and the Sony’s un-muddied delivery maintaining the rhythmic feel.
In a far softer example the Sonys clarified the atmosphere around the intimate piano refrain in the track 4bit by #1 Dads, helping spotlight the tender vocal performance and provide space for much greater impact when the subtle bass line falls in place.
Those with LDAC-compatible phones can take advantage of this Sony-developed codec which offers streaming up to 990kbps — though the connection quality governs this, and it may fall back to either 660 or 330kbps. The full connection quality allows lossy streaming of high-res music, while Sony’s DSEE Extreme engine upscales even sub-CD-quality files to what Sony has called “near high-res”, meaning they can neither measure nor hear a difference with all but the most dense music files. Those without LDAC, however, will have their Bluetooth transmission dropped to AAC, good for Apple devices, or the base-level SBC codec. Those with devices supporting aptX are out of luck here.
Verdict
The true wireless format is no longer in its infancy, and prices have dropped for even solid pairs of earbuds, leaving the Sony WF-1000XM4 squarely at the premium end of the category. But they excel across the board — build quality, battery life, audio performance, noise-cancelling, even now reasonably rugged wearability. If you can live without some of those, you may choose to aim lower. But for those seeking the best allround buds on the market, the $450 asking price for the WF-1000XM4 is certainly fair, and given Sony’s history of discounts after release, we expect this proposition will only become fairer with time. Harry Domanski