Sony WH-1000XM4: First Impressions with an underwhelming upgrade

There was almost a two-year gap between Sony releasing the WH-1000XM3 and WH-1000XM4. The many retailer listings that surfaced earlier this year suggest that the worldwide pandemic probably delayed Sony somewhat, but we digress. We were itching to try the WH-1000XM4 following last month's launch, so we purchased a pair of the Silver ones.
Sony continues to sell the WH-1000XM range in two colours, as it has for years now. Sadly, that consistency, or lack of imagination depending on how you look at it, sums up the WH-1000XM4. The headphones retail for US$349.99 and £349.99 in the UK, making the WH-1000XM4 just as expensive as the WH-1000XM3. However, the latter now cost around US$100/£100 less than Sony's latest model, which is worth keeping in mind if you are upgrading from headphones other than the WH-1000XM3.
Essentially, Sony has made hardly any design changes with the WH-1000XM4. The headband is slightly thicker the one on the WH-1000XM3, for example, while Sony has re-named the NC/AMBIENT button "Custom". Similarly, the hinge mechanism has been redesigned, but these changes are only noticeable with the WH-1000XM3 side-by-side for comparison.
So, if Sony has not made many external changes in two years, then it must have improved the WH-1000XM4 in other ways? Well, yes and no. On the one hand, the WH-1000XM4 can connect to two devices simultaneously, which is a welcome change from past WH-1000XM series headphones. Sony has also included an IR sensor, which allows the headphones to pause or play automatically if you remove the headphones from your head.
Additionally, the WH-1000XM4 has a "Speak-to-Chat" function that amplifies ambient sounds if you begin talking. In our experience, holding the right earcup to amplify ambient sounds is more intuitive, making Speak-to-Chat feel more like a gimmick than anything else. Likewise, Sony claims that the WH-1000XM4 will automatically power off when not in use. However, the WH-1000XM range has done this since at least the WH-1000XM2, so this is nothing new. Sony has implemented "Precise Voice Pickup" technology too, which uses five of the microphones inside the headphones to optimise call quality. Finally, the WH-1000XM4 supports Bluetooth 5.0, an upgrade from the Bluetooth 4.2 of the WH-1000XM3.
All that sounds promising, but it is poorly implemented. Firstly, the WH-1000XM4 cannot connect to two devices simultaneously over LDAC. Conversely, the equaliser within the Sony Headphones app now works with LDAC, which is handy. Theoretically, the IR sensor should work well, too. However, we encountered multiple issues on Android and Windows 10 where the headphones would do the opposite of what we wanted them to. For example, pausing the WH-1000XM4 when connected to a Windows 10 laptop and removing them for our head caused the headphones to resume whatever was playing. Putting the headphones on again resulted in the music stopping. However, pausing the music manually while the headphones were removed resolved the issue. We only experienced this on iTunes, but it is not something we would expect from US$350/£350 headphones.
Setting that niche gripe aside, Qualcomm aptX and aptX HD have been removed from the WH-1000XM line as Sony has switched to a MediaTek chipset. While this does not post any practical restrictions for Android smartphones or iPhones, macOS and Windows 10 do not support LDAC. Similarly, we could not get the WH-1000XM4 to stream in LDAC on the LG V60, so we had to make do with AAC. We had no issues with the Pixel 4 XL though.
Battery life remains unchanged from the WH-1000XM3, too. This is not necessarily a bad thing as the WH-1000XM3 has exemplary battery life. We would have expected at least some improvements in almost two years, though. Android Authority actually found that the WH-1000XM3 outlasted the WH-1000XM4 by around four hours.
We noticed no discernable improvement in call quality, either. It is a similar case with noise cancellation. Android Authority has demonstrated that the WH-1000XM4 has better noise cancellation at higher frequencies, but we have not been on public transport in the past month to notice a difference. Unquestionably, the WH-1000XM4 has excellent noise cancellation, though.
Verdict - Not worth the two year wait
Overall, the WH-1000XM4 feels somewhat of a sideways step for Sony. The company made some decent improvements from the WH-1000XM2 to the WH-1000XM3, but the same cannot be said for the WH-1000XM4. Perhaps we would feel differently if Sony had released the WH-1000XM4 a year after the WH-1000XM3, but its latest effort feels staid almost two years on from its predecessor.
The features that Sony has added feel half-baked too, like the inability to connect to multiple devices using LDAC. Worse still, Sony is yet to address call quality, one of the worse aspects of the WH-1000XM2 and WH-1000XM3. In our experience, even the Surface Headphones 2 has better call quality than the WH-1000XM4, which is unforgivable considering the gulf in price.
In short, if you already have a pair of the WH-1000XM3, then do not upgrade to the WH-1000XM4. And if you do not own the WH-1000XM3, pick these up instead and save yourself around US$100/£100.