Sony WF-1000XM4 true wireless earbuds review: So close to perfect

A new standard for true wireless earbuds?

It has taken almost two years but the long-awaited successor to the WF-1000XM3 is finally here. And, unsurprisingly, Sony is calling it the WF-1000XM4. These are Sony’s new flagship true wireless earbuds and the changes are numerous.

Sony boldly claims it delivers “industry-leading noise cancellation” but the world of flagship-class true wireless earbuds is drastically different from two years ago. So let’s take a closer look and see if Sony has been doing its homework.

Design & controls

You can immediately tell from the moment you open the WF-1000XM4’s packaging that Sony has put a lot of thought into this product.

Putting aside the fact that the packaging is mostly made out of recyclable and sustainable materials, the WF-1000XM4 earbuds look nothing like their predecessor.

Using data of ear shapes from around the world, Sony has made big changes to the way they look and the way they wear. The WF-1000XM4 earbuds are more bud-like, rounder, and less bulky. The result of this new design is that they fit better than their predecessor.

In the ears, they feel more snug and secure. Even when I’m running, they stay put. Sony says overall volume has been reduced by 10 per cent but to me, it feels like a lot more. I suppose that’s intelligent design.

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The new design makes the WF-1000XM4 earbuds more comfortable to wear for long periods than their predecessors.

But I won’t say they are the most comfortable.

The AirPods Pro remain the gold standard but the WF-1000XM4 are on par with rivals like Sennheiser’s True Momentum Wireless 2.

Because of their snug fit, you still feel them in your ears and they don’t quite disappear like the AirPods Pro do.

I could wear them for around two to three hours before I feel like I need to give my ears a break – your mileage, of course, may vary.

The charging case charges via USB-C and supports wireless charging. It has been downsized too, to the tune of a whopping 40 per cent. It’s considerably more compact and more comparable in size to its rivals.

But perhaps most importantly, fits comfortably in pockets. Owners of the WF-1000XM3 who found its charging case to be too cumbersome might want to upgrade just for the more pocketable charging case.

The WF-1000XM4 comes in black and silver (more like beige, actually). Both units feature gold accents and both look attractive. But if I had to pick, I’ll go with black. They are IPX4 water-resistant which, according to the IP code, means they’ll withstand splashes of water and sweat.

The large circular panels on the earbuds are touch sensors. By default, the left sensor controls the active noise cancellation modes while the right sensor is used for playback controls.

You can customise these controls in the app but Sony only lets you choose from predefined templates. For example, you can add volume control to the touch sensor but at cost of giving up either active noise cancellation controls or playback controls.

If it’s any consolation, these touch sensors are one of the most responsive that I’ve used in a true wireless earbud. Inputs register cleanly and consistently so controlling the earbuds was a cinch.

Also helpful is the fact Sony is one of the few companies that insist on using voice prompts to let people know what’s happening to the earbuds as opposed to some brands that use ambiguous bings and bongs.

So if you are switching between noise cancellation and ambient sound modes, the earbuds will announce it so you know exactly if your inputs have been properly recognised.

For full control over the earbuds, you’ll want to use Sony’s Headphones app.

Apart from letting you customise the touch controls, the app also lets users manage the intensity of noise cancellation, activate/deactivate the Speech-to-Chat function, tune the sound with the equaliser, update the earbuds’ firmware, and more.

It’s not the prettiest app and it can be a little confusing for newcomers to find where certain settings are but it works well enough.

One feature in the app worth highlighting is the one that helps you determine the best ear tips for your ears. It measures the seal, which is crucial for any in-ear headphone to sound right. To use it, find the option in the app and it will start playing a test tone.

Once that's done it will generate results informing you if the tips are air-tight. It takes a lot of the guesswork out and makes it easier for users to identify the right ear tips for their ears.

ALSO READ: Sony unveils new flagship true wireless earbuds, meet the new WF-1000XM4

Noise cancellation & mic quality

Inside the WF-1000XM4 earbuds is the all-new Integrated Processor V1. Sony is quite vague on what exactly this new processor does and only says it “takes the noise cancelling performance of our acclaimed QN1e chip and goes even further”.

It’s supposed to deliver better noise cancelling performance while consuming less power. The setup also consists of two noise-sensing microphones per earbud – one feed-forward and one feedback. This dual microphone setup is also used by Apple’s AirPods Pro.

Noise cancelling performance is outstanding. It is hands down the most silent true wireless earbuds that I’ve ever experienced. I could barely hear the two fans that I have arrowed at me during the warm afternoons.

It’s the same when I’m walking outside along the street – passing traffic becomes just a mere whisper.

So impressive is its ability to cocoon you that I think the WF-1000XM4 earbuds is almost on a par with the larger WH-1000XM4 – though I think the over-ear cans are just a tad quieter.

I’m sure the new Integrated Processor V1 has a large role to play in it but I’m certain the new ear tips do as well.

It seems these aren’t just ordinary ear tips. Sony has a name for them: Noise Isolation Earbud Tips. They are made from a “unique polyurethane foam material” and feel like a cross between silicone and memory foam ear tips.

I’m well acquainted with Comply’s foam tips but these tips from Sony seem to provide a better seal and more isolation. My only concern is longevity since foam tips typically require replacing quicker and because replacement tips are $29 a pop.

The WF-1000XM4 earbuds have an ambient sound mode that lets in outside noise – handy if you are jogging and walking on a busy street. It’s much improved compared to its predecessor and even the WH-1000XM4.

However, Apple’s implementation in the AirPods Pro is still the one to beat.

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The mics are passable. Apple’s AirPods Pro are still the benchmark and they trounce the Sonys in terms of clarity.

The WF-1000XM4 earbuds, to their credit, are an improvement over their predecessors and they do a good job of suppressing external noise.

The problem with them, however, is that they sound noticeably more muffled than their rivals.

Once they are set up, the WF-1000XM4 earbuds connect very quickly.

That has to do with its new Integrated Processor V1 chip. This chip supports independent transmission – that is to say signals are streamed independently to each earbud.

This approach reduces latency and allows for a more stable connection.

I tested the earbuds with an iPhone 12 Pro Max and a M1 MacBook Pro and I found that connection was generally stable. There was the odd dropout here and there but nothing persistent nor serious. Range was decent.

I could get about 8 to 10 metres away in my apartment before the earbuds struggled. And no, I didn’t encounter issues with the TraceTogether app running.

The WH-1000XM4 earbuds are supposed to support Swift Pair with Windows devices but I couldn’t get them to work with a Surface Laptop 4 that I happened to be testing.

Latency wasn’t an issue either, I watched two episodes of the thus far excellent Loki and I couldn’t detect any syncing issues.

One glaring shortcoming of the earbuds with regards to connectivity is the lack of multipoint support so they only connect to one device. If you want to switch source devices you’ll have to go through the pairing process again.

This is perplexing because multipoint is supported by the WH-1000XM4.

But to be fair, multipoint support is a feature that is missing on other flagship true wireless earbuds including those from Bose, Sennheiser, and Apple – though Apple mitigates this somewhat by using iCloud as a crutch to enable auto-switching of devices.

If multipoint is important to you, it seems that only Jabra earbuds do it.

Codecs supported are SBC, AAC, and LDAC. aptX is curiously missing which could be an issue for Windows PC users at least until AAC support comes later this year.

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LDAC support should be tantalising to audiophiles because of the higher data transfer rates (up to 990kbps). In the app, you can prioritise between sound quality and stable connection. AAC and LDAC is called on when you select the former while the latter relies on SBC.

Because I was testing with an iPhone and Mac, I made sure I used AAC.

Battery life was impressive. Sony claims up to eight hours on a single charge with ANC and that goes up to 12 hours if you turn ANC off.

That claim seems to be spot on, I managed to get through an entire day from morning till the night with on and off listening with no problems.

The charging case provides an additional two charges so you can get up to a whole day’s worth of music listening.

And if you are out of juice, five minutes is all it takes to give you up to an hour of listening time. 

nside the WF-1000XM4 are 6mm dynamic drivers. It sounds small in comparison to rivals like the FreeBuds Pro have massive 11mm drivers. But as it is often said: size doesn’t matter, it’s what you do with it that counts. 

Tonality and timbre are excellent. The overall signature is slightly dark with tastefully elevated and powerful bass, balanced mids, and somewhat recessed but easy-to-listen-to highs.

But you can pick holes, these are the first word in clarity nor are they the most detailed or resolving. Consequently, you hear the notes and don’t you don’t quite feel them like the very best-sounding earbuds help you to. Still, there’s also a naturalness to the way it sounds.

And ultimately, these are easy earbuds to kick back to and enjoy.

Against the WF-1000XM3

The WF-1000XM4 earbuds are incontestably the superior earbuds. They are more compact and portable, more comfortable to wear, have better mics, and crucially, deliver better noise cancellation. If you are wondering if you should upgrade. The answer is an emphatic yes.

Against the WH-1000XM4

This probably isn’t the fairest match up but one worth considering since both are Sony’s flagship ANC personal audio devices. In terms of noise cancellation, the two are very close but the larger WH-1000XM4 has a very slight edge – that’s how good the WH-1000XM4s are.

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As for sound, I prefer the WF-1000XM4s’ more laidback sound as opposed to the WH-1000XM4’s more aggressive approach.

The WF-1000XM4 are irrefutably more portable.

However, if you are thinking of using them on a plane (yes, one can always plan ahead and dream about flying again) then the WH-1000XM4 are more versatile since they come with an airline adapter and will plug into the in-flight entertainment system.

If you intend to use the WF-1000XM4 earbuds on a plane, you’ll either have to use them only with your own devices or get some sort of an airline Bluetooth transmitter. 

Against the AirPods Pro

If you have multiple Apple devices and often switch between them, I think the AirPods Pro are the better option. Automatic switching, when it works (yes, it can be buggy at times), feels like magic.

Furthermore, the AirPods Pro are more portable, more comfortable to wear, and more affordable. However, if you only use one or two Apple devices, then the benefits of auto-switching are not so obvious and you might want to consider the WF-1000XM4.

The WF-1000XM4 sound better, have superior noise cancelling, and longer battery life.

Against the Sennheiser Momentum True Wireless 2

The Sennheisers sound better. Their tuning is more refined and balanced, the soundstage is wider, and their drivers extract that little bit more detail. And for users who need aptX, it’s one of the few earbuds to support it.

The Sonys counter with better noise cancellation and superior battery life. They cost about the same. If you find yourself in noisy environments often, I think you will be happier with the Sonys.

The new yardstick

The WF-1000XM4 earbuds aren’t perfect but they get really close. Comfort has room for improvement, the mics make you sound muffled, and the lack of support for multipoint connection is a real disappointment. But really, these are the only noteworthy niggles for me.

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At $379, they are a little bit pricey – the same can be said for any flagship-class product these days – but at least these earbuds back up their price tags with some truly impressive performance.

Their new design has done much to improve portability – I can now easily fit them in my pocket without looking like I have a questionable bulge in my pants.

Noise cancellation is superb and the way they sound is just so alluring and enjoyable. Battery life is outstanding too. 

We might be only halfway through the year but I see these earbuds as the forerunners in the Best True Wireless Earbuds category in our next Tech Awards. Rival brands will need to pull something very special out of their hats to stand a chance.

That’s how good Sony’s new WF-1000XM4s are.

This article was first published in Hardware Zone.