Sony WF-1000XM4 Review: ANC King

July 12, 2021

Like many of you, I have been waiting for Sony's long-rumored and long-awaited Sony WF-1000XM4. The previous generation WF-1000XM3 is still one of the best active ANC truly-wireless earbuds on the market. Can the new Sony WF-1000XM4 take away from the crown? Are they worth the upgrade? Let us find out.

Disclaimer: I purchased all devices reviewed in this article. I did not receive any review units from Sony. I am NOT sponsored or affiliated with Sony in any way. I do not accept copy approval from Sony or any other organization. All opinions are mine and mine alone.

Specifications

Sony WF-1000XM4 Diagram

  • 🔋 Up to 8hrs with NC on (AAC), 16 hrs for the case
  • 🎨 Black or Silver
  • 🎵 SBC, AAC, LDAC
  • 🎁 Active noise canceling, IPX4, DSEE Extreme, Fast Pair
  • 🔌 USB-C, Qi Wireless Charging
  • ⚖ 0.2 oz earbuds, 2 oz charging case
  • 💸 $280
  • 📅 2021.06.08

What has changed?

The Sony WF-1000XM4 is the direct successor to the WF-1000XM3. If you haven't figured it out yet, the naming scheme of Sony devices breaks down like this. WF stands for Wireless Freedom. 1000X is the line of product. M4 stands for Mark 4 (aka the fourth generation of that line).

Much has changed in the WF-1000XM4 compared to its predecessor:

  • Both the case and earbuds are significantly smaller
  • The device now supports LDAC
  • The case now can charge through Qi wireless charging
  • Battery life has increased from 6 hrs to 8 hrs of music playback with ANC for the earbuds
  • Battery life of the case has decreased from 18 hrs to 16 hrs
  • Bluetooth has been upgraded from v5.0 to v5.2
  • The WF-1000XM4 now have IPX4 water resistance
  • There is no NFC support on the WF-1000XM4
  • Price has also increased from $230 to $280

Build Quality

The build quality of the Sony WF-1000XM4 is solid. I did notice the charging case is much lighter than the WF-1000XM3. Sony reduced case size without sacrificing much of the battery and durability. The charging case now comfortably fits into the pockets of a pair of jeans.

The earbuds feel solid too. They can survive a moderate drop from 5-6 ft without breakage (though I still wouldn't recommend it).

Sound quality

The sound quality of the WF-1000XM4 is lovely. The WF-1000XM4 tends to be more bass-heavy and not as vibrant near the highs. You can correct this by switching to the "Bright" EQ or customizing your own. The sound space is shallower than a pair of headphones like the B&O Beoplay HX. They are still quite pleasant for earbuds. Overall, I enjoy the sound quality of the WF-1000XM4s.

Comfort and Fit

The WF-1000XM4 comes with three different ear tip sizes (small, medium, large). This year, the WF-1000XM4s come with Sony's uniquely designed ear tips. They are a combination of a foam outer layer and a silicone inner layer. The ear tips slightly more durable while providing the same superior seal of foam tips. A large part of why the WF-1000XM4's ANC is so powerful is due to these ear tips.

The Application

Sony uses the same "Headphones Connect" app to let you control the settings on the WF-1000XM4s. The earbuds do have some type of onboard memory that stores the settings on the device. The settings for the WF-1000XM4 are pretty similar to the WH-1000XM4s. Features like "Speak to Chat", where the music pauses when you speak, are here. "Adaptive Sound Control", a feature that uses your location and the proximity sensors to determine whether to turn on ANC or ambient sound, is here as well. A new ANC mode that adds wind noise reduction that works quite well while walking around the city. One interesting feature added allows the ability to detect whether you are wearing the right ear tip.

For a comprehensive look at all the settings available for the WF-1000XM4, check out the video below.

There is one disparity in the app that I found confusing. There are two places where you can set the "Wireless playback quality" and they are independent of each other. One place is the "Headphones Connect" app from Sony. The other is the settings menu of the Android phone. It is possible to set the Android setting to "Best effort" and the Sony app to "Priority on Sound Quality". It is unclear to me if this is a bug or just a poor UX.

Battery life and Charging

Battery life on the WF-1000XM4s has been pretty good. The earbuds are rated for 8 hrs of music playback with ANC on. In my experience, I get about 6.5 hrs with ANC and LDAC on. If I switch to AAC with ANC on, I get 8 hrs and 35 minutes.

My left earbud gets significantly more battery life than my right. In my tests, the right earbud will die first. The left earbud still has ~23% more battery. The 23% translated to 1 hr and 3 minutes more battery life on the left earbud (a total of 9 hrs and 38 minutes). I haven't seen such a variance in the two earbud batteries before. Some have said this is a bug where the right earbud drains more. Others have had luck disabling some features to get them more aligned. I have not. I wouldn't do an exchange just because the batteries are not aligned. It is pretty common for there to have differences between batteries. As long as your battery lasts the same or more than the rated battery life, you are good. Some may classify this as a manufacturing defect, but I think swapping them out adds to the e-waste problem. Two batteries that are rated the same do have variances in battery life. To make them more aligned, I would expect the manufacturing to reject a lot of batteries. That would also add to the growing e-waste problem. Sony could software lock the battery capacity (Tesla does this with their cars) to make them more aligned. I find this kind of silly and would rather be happy with the bonus battery life.

Want to know more about how much battery life you'll get with different audio codecs and settings? Sony published a super detailed chart on their website just for this:

Sony WF-1000XM4 Battery Life

The charging case is considerably smaller (40% smaller than the WF-1000XM3) and includes Qi wireless charging. Popping the earbuds back in the case for 5 minutes will give you up to an hour of music playback. A fully charged case gives you an additional 16 hrs of music playback. These earbuds will last you through a long day if you take some breaks and quickly charge in between your workday.

The battery indicator light is gone from the earbuds. There is now only a single light indicator on the case that will shine green, yellow, or red depending on the various state of the device. It did take a while to get used to this change. Here are all the various statuses that the light can indicate.

Microphones and Call quality

Microphone performance is still not the strong suit of Sony audio products. That is not to say they haven't improved. These now include bone-conduction sensors that will make sure the microphones only pick up on your voice rather than the ambient sound around you. It works well enough for me during meetings and calls in a moderately quiet place. They won't work too well in a very windy or noisy environment.

Water resistance is here as well

Finally, Sony has opted to get an official water resistance rating for the WF-1000XM4s. The IPX4 rating should allow you to use these earbuds in light rain and prevent your sweat from destroying your earbuds.

Eco Paper Packaging

Sony WF-1000XM4 Eco Packaging

Sony has opted to use bamboo, sugar cane fibers, and post-consumer recycled paper for the WF-1000XM4's packaging. What you get is a bento box-like design that completely removes the need for any plastics. I am happy to see Sony continuing to develop its green initiatives. I would love to see how this type of box might translate to their smartphones and other products.

Superior Active Noise Cancellation

Combined with ear tips, the ANC cancels out most of the other ambient sounds. The ANC is almost as good as their WH-1000XM4s, which is impressive for a pair of wireless earbuds. The ANCs are also better than the B&O Beoplay HX. An ANC earbuds trading blows with high-end ANC headphones is just unexpected.

The Experience: On the Plane

I was fortunate enough to test the WF-1000XM4 on a plane ride. The WF-1000XM4 performed better than my ANC headphones. The noise level was reduced to that of a quiet library. Flight announcements were audible but muffled. There was a bit of pressure coming from the ANC. Readjusting the fit did relieve some of the ANC pressure. The pressure was still significantly higher than my ANC headphone. If your ears are sensitive to ANC pressure, you might want to look elsewhere.

There is a bug where ANC quickly disengages and re-engages between songs and with the music paused. This issue is present when using LDAC but rare on AAC. Sony seems to be aware of this bug and, hopefully, this is a software problem and not hardware. I don't find this issue to be a deal-breaker, more of an annoyance. I can understand how some might find this unacceptable for $280. I will post an update if this does end up getting fixed.

Update (2021.07.27): Sony released firmware v1.2.6 that resolves the "swoosh" bug mentioned above. After a couple of hours of testing, the firmware does seem to resolve the issue completely

The Experience: Sony WF-1000XM4 ANC versus 17 Year Brood X Cicadas

If you are in the Mid Atlantic area of the US right now, you know that the 17-year Brood X cicadas are out and about. These are loud insects that come out in swarms every 17 years. There are so many of them that they are showing up on weather radars. Surprisingly, the WF-1000XM4's ANC is incredibly effective against them. With music and ANC on, you barely can hear the sound of their loud chirping.

The Experience: Working out

Working out with the WF-1000XM4s has been great. The earbud design makes them secure enough in the ear that I do not have to worry about them falling out of my ear. I have had no issues with them falling out while running, jumping jacks, and weight lifting.

Missing multipoint support

Sony did not include multipoint support for the WF-1000XM4. This is an odd omission for these $280 earbuds. If that is something you need, you'll be better off with a different set of earbuds. I haven't found earbuds or headphones that have a good multipoint implementation. The entire process of seamlessly switching between devices tends to break down when you try to swap one of the two devices for a third device. I am not too bothered by the omission of multipoint here.

Price is steep, but align with competition

There is no way around this. The Sony WF-1000XM4's price is high. $280 is a lot to spend on a pair of earbuds. I wouldn't say that their price is unexpectedly high. They slot nicely with the $250 Apple Airpods Pro and $300 Senhiessers MOMENTUM True Wireless 2.

Recommendations

Sony took the list of complaints from the WF-1000XM3s and made improvements on all aspects. The resulting WF-1000XM4 is a featured-packed truly-wireless earbud that is top of its class. Yes, $280 is a lot to spend on earbuds. But frankly, given how well-rounded these are, I can see how these could be your single go-to earbuds. These earbuds perform admirably, whether for exercising, traveling, video conferencing, or enjoying music. If you want a single set of earbuds that will work well on most occasions, these are worth saving up.