In-Ear Fidelity

Sony WF-1000XM4 Review: The Audiophile’s Perspective

Table of Contents


Back in the ancient year of 2017, Sony came out with the WF-1000X right at the advent of the “true wireless earbud”. It wasn’t the best and was subject to many of the problems that other first-gen TWS buds had, and so slowly faded from public consciousness as newer and improved alternatives popped up.

Then, the breakthrough. Skipping an entire “XM2” generation in its naming scheme, Sony released the WF-1000XM3. Immediately it stood out as being one of the best-sounding TWS sets one could buy, and even took top spot on my TWS Buyer’s Guide at the time of its release (it had since been dethroned by the likes of AKG and Samsung, but I digress). Coupled with the release of the ever-popular AirPods Pro gave the XM3 an added boost in popularity as “the alternative”, and so cementing its status as one of the default recommendations for the high-end TWS customer.

And with the release of the WH-1000XM4 headphone, it’s no surprise that Sony seeks to continue capitalising on the still-growing TWS industry with their newest update to the WF-1000 line: the WF-1000XM4. With completely redesigned housings for both the earphone body and the charging case, the XM4 seems to be more an overhaul rather than minor refinements to its predecessor.

Enough talk, you’re probably not here for mere exposition. Now we answer the question: how good is the WF-1000XM4 actually?

Product page:

MSRP: $280

Driver configuration: single dynamic driver


And Non-Audio Opinions

If you’re not interested in the following, you can skip right to the next section using the Table of Contents above. This section is only published on reviews and articles that would attract a more mainstream audience (e.g. my AirPods Max review).


So first and foremost, I’m sure there’ll be many reading this review who aren’t familiar with me or my work who would (understandably) be asking: who is this guy? Why is he calling himself an audiophile? Why should I listen to him?

Hello, I am known as “crinacle” and I run In-Ear Fidelity (IEF), a fully independent website dedicated to the “portable audio” scene of the audiophile hobby, mainly focused on headphones and earphones. I first started in the hobby in the late 2000s (the earliest official record being my Head-Fi registration in 2011) and started getting a reputation for myself only around 2016, with the IEF website being created in early 2019. In short, I’ve been in the hobby for a little over a decade, and been involved in the audiophile community for a little under that.

(Do note that the portable audio hobby is relatively young, so don’t expect your average “veteran of the hobby” to have “decades of experience” like with the 2-channel speaker world.)

Currently I maintain the world’s largest public database of frequency response measurements for headphones and earphones, and I also maintain highly popular ranking lists of (most of) said headphones and earphones (currently at over 900 earphones and over 200 headphones respectively).

This is my full-time job so one could call me a “professional” considering that, well, this is my profession. It is my job to keep up to date with the audio scene, provide my thoughts and opinions on various products and topics, and of course making sure that my measurements database don’t go obsolete by keeping it updated with new releases. 

As for why you should listen to me… that’s really your call to make. On many occasions I’ve labeled myself as simply “a guy on the internet” because that’s really all I am: just one of the many voices out there in the world. And while of course nobody should take my word (or anybody else’s) as gospel, I do hope that you would take my opinions into consideration when contemplating a purchase. If anything else, at least just for audio-related concerns since that’s my specialisation.

ANC, Ambient mode & Isolation

Performs about the same as the AirPods Pro, better than the Samsung Galaxy Buds Pro. Pretty good, but won’t hold a candle to the WH-1000XM4 headphones.

Comfort & Fit

The shells are massively improved over the XM3 which results in a far better and more secure fit, though the buds themselves are still some of the largest in the TWS market. Still pretty comfortable for me.

(Note: my ears are abnormally large, so my experiences will probably not mirror yours.)

Battery Life

  • 8 hours on ANC
    • Additional 16 hours with the charging case
  • 12 hours without ANC
    • Additional 24 hours with the charging case

This is above the par for the average TWS set, which is about 6 hours of use without the charging case.

Equaliser Presets

The Sony Headphones app (Android, iOS) supports the use of different equaliser presets, namely:

  • Bright
  • Excited
  • Mellow
  • Relaxed
  • Vocal
  • Treble Boost
  • Bass Boost
  • Speech

Below are the frequency responses of each EQ preset (all of which have also been uploaded to the Graph Comparison Tool):

All the presets on one graph, if you can read this spaghetti.

However under IEF rules, the use of software EQ is not a consideration when evaluating an IEM. By all means feel free to use the presets, but only the XM4’s stock tuning will be factored into its final gradings and overall rank.

Signature & Tonality

For an explanation to what “tonality” is, refer to this article.

Not sure how to read graphs? Click here

This review is based on a stock configuration WF-1000XM4 connected to a Samsung Galaxy Z Fold2 as well as an iPhone 7 Plus.

The sound signature of the XM4 can be described as “warm”. It’s a downsloping response where the bass is most emphasised, followed by the midrange, and the treble being the most recessed.

This gives the XM4 a richer and more “dense” quality to its notes, at least relative to your average V-shaped IEM or even something that’s tuned to the Harman target (something that is pretty common in the TWS market due to the ubiquity of DSP). That pretty much means that the XM4 is going to be a little better in lower-pitched instruments like cellos, bass guitar, or even male vocals (relative to female vocals at least), though balanced enough where it’s not a complete wash on the higher-pitched stuff.

The laid-back presentation also helps with fatigue and overall shoutiness, though at the expense of the bite and energy that gives certain instruments that satisfying edge (electric guitars for instance). So for those who are more sensitive to higher frequencies, the XM4 would score a point here.

Overall, the XM4 has a largely inoffensive tonality that is also balanced enough to not throw the general timbre of instruments off. A precise and calculated tuning designed with intentional colouration.

Tone grade: B+

For more information on the grading system, click here


For an explanation to what “technicalities” are, refer to this article.

Not the worst, in fact it’s arguably good. Just don’t expect it to outcompete against the top dogs in the wired arenas.

I’ll paraphrase what I’ve said in my Galaxy Buds Pro review since it’s extremely relevant even in this case:

The [WF-1000XM4] has a ways to go when fighting against the wired crowd on the technical front. With the [WF-1000XM4] it’s more obvious than ever that the Bluetooth TWS market has hit a wall in terms of “the intangibles” (resolving ability and imaging, though the former is more relevant in this discussions). And while the [WF-1000XM4] aren’t bad by any means, it’s one of those cases where I can see the unfulfilled potential bottlenecked by… something. Whether it being the Bluetooth connection or the quality of the drivers themselves, that is a separate topic altogether.

Next to something like, say, a Moondrop Blessing 2 (one of the best $300 wired IEMs available), the difference in detail retrieval is apparent. Sure, the Blessing 2 has higher clarity (which is a function of frequency response) but also manages to resolve more low-level detail than the [WF-1000XM4], which sounds a lot more obscured in comparison. 

The XM4’s warm tuning doesn’t do it much favours on the technical front either, making it such that perceived detail also takes a substantial hit in comparison to brighter sets like the Buds Pro and the N400. So while the TWS market has evolved astonishingly fast in the last few years… there are still some things that wireless data transfer simply can’t do.

Still a technically decent IEM though, all things considered.

Technical grade: B

For more information on the grading system, click here


A brief primer on my valuation system, I give out “awards” based on three merits:

★: “Worth the price”
★★: “Redefines the price bracket”
★★★: “Worth the Blind”

Here is the important part though, these are awarded purely on the basis of sound quality. After all, this is an audio-focused headphone review website, and as such the ratings are audio-focused as well.

At $280, the XM4 is no Buds Pro ($200) and closer to that of the Apple AirPods Pro ($250), which has positioned itself as the TWS buds to beat. It’s a pretty simple case of extrapolation here: the XM4s are sonically better than the AirPods Pro which themselves are actually “Worth the price” under IEF metrics (if just barely). And while the XM4s don’t quite live up to the even cheaper Buds Pro and N400… that just means that they’re out of the running of the 2-star award.

In terms of audio performance, are the XM4s worth the price? I’d say absolutely. Great tonal balance and decent technical performance at a sub-$300 price point; there aren’t many who would complain about that.

Value Rating: ★

“Worth the price”
For more information on the grading system, click here

XM3 vs XM4

Here’s the obvious comparison: the WF-1000XM3 versus the WF-1000XM4.

Loyal readers of this website would know that I put zero stock in the mantra of “newer is better”; in fact in many cases newer releases tend to be worse than their older, more established counterparts in the audio world. 

Now, there are obviously a multitude of non-audio improvements when going from the XM3 to the XM4; for instance the build is far less bulky and fit has improved substantially due to that, or the addition of 2 more hours of battery life in the earbuds themselves, or even the new IPX4 rating that the XM3 failed to achieve. Overall the XM4s are a better product, but unfortunately we only care about sound here.

The big difference between the XM3 and XM4 would be in stock tuning; the XM3 has a noticeably higher lift in the upper mids to treble in comparison, which helps pull the tonal balance back into more “neutral” territory (though would still be classified as a V-shape regardless). Between the two, the XM3s just sound a lot more lively and the extra brightness helps round off the bass boost a little better than the XM4’s warm-downslope, which helps with instrumental timbre quite a bit.

Now obviously one could absolutely prefer the sound signature of the XM4 and so these criticisms are all moot. But under IEF metrics, the XM3 would have the upper hand by virtue of its tonal superiority.


The WF-1000XM4 deviates slightly from its predecessor by adopting a warmer, more bass-focused signature. While I’d find the XM3s a little better tuned, the myriad of other non-audio improvements makes the XM4 a rather compelling purchase for the high-end TWS user.

Grade: B

Awarded grades are in reference to the Ranking List.

For those interested in a larger perspective into the TWS market as a whole, do take a look at my Buyer’s Guide below.

Support me on Patreon to get access to tentative ranks, the exclusive “Clubhouse” Discord server and/or access to the Premium Graph Comparison Tool! My usual thanks to all my current supporters and shoutouts to my big money boys:

“Uncharted Waters”
Man Ho

15 thoughts on “Sony WF-1000XM4 Review: The Audiophile’s Perspective”

  1. Great initial review. I’d love to hear your thoughts on how it compares to the Samsung Buds Pro.

  2. Crin, have you tried using LDAC as the codec? The XM4 supports LDAC and I would believe that the resolving capability is higher when using this codec.

    1. Highly agree. Allot of folks dont realize you have to go into bluetooth settings and tell it “Yes I friggin want High quality over distance!!”. I have mentioned that on several forums and usually folks get back with a “Wow these really sound good now!” LDAC is impressive. Big fan of the fiio necklace thingy and the btr5. Sounds darn close to wired IMO!

  3. Very interesting: Buds > Buds+, XM3 > XM4…older=better 😉

    The Cambridge Melomania 1+ / Touch (7mm driver) could be a very good alternative. It seems that they are very good TWS and in a league with Sony or Samsung. Maybe there is a chance to test them.

    So for ios – Users the Buds+ (neutral, flat) oder Xm3 (bit more fun, bass) are actually the way to go. Very cheap and a good sound. It’s a pitty that Samsung doesn’t offer an ios-App for the Buds Pro :(.

  4. Ive been waiting for this review, for a long time, thanks crin, ill keep and continue to enjoy my buds pro, as for sony, THEY SURE FCKED UP, 2 years for this bass bloat garbage xm4

  5. First of all thanks for this review. I’d like to ask, if there is any chance, you will review the Bowers & Wilkins PI7/PI5? This would be awesome 🙂

  6. i bought these after seeing that they were seemingly the top of the current generation of TWS but to my dismay i still find the idea of TWS lackluster. While the battery life of the XM4s was amazing i personally didnt like the comfort of sound signature. If i compare my Fiio FH5 Fiio BTR5 combo for portability at roughly the same price (XM4s were $300 after taxes for me) i would rather keep the cable and gain the modularity of the BTR5 accepting any and all IEMs with a 3.5mm/2.5mm cable and a battery that lasts me a full 9-10hrs of workday from wake up to getting home.

  7. Man, love your articles! But, as people mention above, we need more answers! : )

    I just ordered WF-1000XM4 and can’t wait to try them out properly with maxxed out settings: LDAC on NW-WM1A, PCM 32/384 and DSD 11.2MHz played Natively. LDAC is close to 990kbps or 24/96 – should be impressive…

    Currently Apple AirPods Pro paired with NW-WM1A sound very noticeably better, compared to when used with iPhone. AirPods Pro operate at 32/48 – which results in higher SNR (quiter background and clearer sound) and a bit warmer sound.

  8. Got my Sony WH-100XM4. Can confirm: they work very well with NW-WM1A. LDAC wireless codec supports audio up to 990kbps: very good, compared to FLAC 16/44 1411kbps.

    FLAC 16/44 sound impressive on them.

    Can play PCM 32/384 and DSD 11.2MHz effortlessly.

    Bass is superb, Sounstage is wide and spacious, great sounds separation and positioning, reproduce a lot of details and, overall, well balanced and engaging.

    Their foam eartips have much stronger passive noise isolation, making background very quiet, greater silence allows to hear smaller details and better clarity of sound. Almost as strong as NC on AirPods Pro.

    Very happy with them so far!

    1. Correction: Linear PCM, a sound format of a CD, has bitrate of 1,411.2 kbit/s or simply 1411kbps.

      Lossless audio formats FLAC or ALAC compress CD audio and have bitrate of 400kbps – 1411kbps.

      I see bitrates of my 16/44 FLAC files vary from 550kbps to 950kbps, that is lower than LDAC with its 990kbps bitrate.

      It means Sony WF-1000XM4 can play 16/44 Lossless – Wireless.

      In a way, you can tell how good they will sound after a burn-in from just hearing them fresh out of the box: details and wide Soundstage are most noticeable, but Bass sounded about 85% its best – which is normal for dynamic driver and in my experience will become overall smooth and balanced in 2-4 weeks time. Need burn-in.

      Same goes to Eartips: a bit tight and hard out of the box – need time to break-in.

      Tested with all Sound Settings Off, playing all files Natively.

      1. Necro post here, but if you go on developer settings on your Android, you can change the LDAC settings from adaptive to best effort. With the best effort, it will try to keep a consistent 990kbps rather than ranging from 300-900. That will come with the cost of connection stability, though can be problematic, especially in highly populated areas with many devices.

  9. I just got them, but unfortunately I’ll have to return them. They sound very weak and anaemic to me. I’m not looking for flat frequency response, I want my music to sound punchy, powerful and immersive.

    1. OK Luka. I understand that it may not be your cup of tea but consider that flat means uncoloured. It means the music is as closed as intended by the sound engineers of the album. The positive about a flat response is that it can be, most of the time, EQ to fit your tastes. If the natural response curve is not flat it is harder to fine tune the curve to your liking without causing a lot of distortion.

      1. Agree. This will sound like name dropping (who me?) But I once worked at Trident Studios in London. I remember the tapes for Elton Johns Black album coming up to the disc cutting room (this was before he’d become famous). I whacked the tapes on and immediately added 3db of top to it. Gus Dudgeon (the producer) seemed to agree with me that it needed brightening. However, Robin Cable, the engineer, then walked in, went straight over to the console and knocked the top back off again….”Dont you know the bloody difference between JBL’S and Lockwoods you ejut”. But it just goes to show how any different and any different set of speakers, let alone your personal taste, can make a huge difference. Dont fool yourself; youll never find the perfect sound system coz it doesnt exist. Tracks/albums are recorded and mixed at many different venues on many different speakers by many different engineers. So I agree…..bring it in flat and leave it to the general settings youve set to compensate for your room, speakers and personal taste and judge the recording by that.

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