Headphone Reviews

You won't see many Apple products in these pages, and for good reason. As Stereophile Editor Jim Austin wrote to me recently in an email, "Apple may have the best acoustic-design facilities in the world, but its products are designed by engineers who don't seem to respect perfectionist sound—which is appropriate for a company that aims for the vast middle of the bell curve." Has that changed?

It took Apple years to get halfway serious about music reproduction. The $2 trillion giant didn't offer lossless files via its Apple Music streaming service until mid-2021. Its early wired earphones sounded tinny and congested, barely a step above free airplane buds. Later models were better, but not by much.

Then, starting with the iPhone 7 in 2016, Apple took away the headphone jack. People who were serious about sound and determined to keep listening "wired"—that is, not via a lossy Bluetooth connection—reluctantly purchased ugly, easily lost dongles-with-tails that spoiled their phones' clean design. Meanwhile, the convenience-minded "good enough" crowd bought a billion wireless earbuds (footnote 1), all hampered by Bluetooth's bandwidth limitations.

To this day, Apple treats even its best wireless listening devices like naughty stepchildren. Neither the $549 over-the-ear AirPods Max (which I auditioned for a few weeks in late 2021) nor the new AirPods Pro 2 in-ear monitors ($249; the product under review) support superior Bluetooth codecs like aptX HD and LDAC, much less hi-rez music. (See Jim Austin's sidebar.) The company, for now at least, sticks to its own AAC codec, which, while better than basic SBC, isn't as good as LDAC or aptX HD (footnote 2).

The new Bluetooth 5.3 standard implemented in the Pro 2s can handle lossless streaming in conjunction with Qualcomm's S5 chip, but Apple literally isn't buying it (the chip that is), preferring its own silicon. This seems to rule out a Pro 2 firmware upgrade that unlocks CD-quality-or-better audio, unless that capability is hidden inside the new Apple H2 chip that drives these AirPods. That's possible, but I shan't hold my breath.

Considering that about 100 million 24-bit hi-rez recordings now reside on Apple Music's servers, it's puzzling that the company doesn't offer a single head-fi product—wired or wireless—that does justice to that higher-quality audio.

So why am I reviewing the Pro 2s for Stereophile? The sound quality of these new IEMs is roughly as good as many (but not all) wired headphones in the same price class. Also, while most of this magazine's readers probably won't buy a pair of AirPods for serious at-home listening, audiophiles' lives extend beyond the listening room, onto airplanes and noisy subways. Are you going to wear your over-the-ear Audeze or Abyss headphones while out and about, perhaps along with a portable headphone amp? Me neither.

Finally, this review is an opportunity to look at a whole class of products. Is wireless listening the devil, or is there a place for noise-reducing IEMs in the lives of audiophiles?

What's new
I've never found it easy to tolerate objects in my ears for very long, so I'm happy to say that by a good margin, the AirPods Pro 2 are more comfortable than any of the IEMs I've purchased over the past few years (the Moondrop Arias, the Etymotic ER4SRs, the AKG N400s, and the first-gen AirPod Pros, which surprisingly I found less comfortable than the new model). The reason: You don't have to screw, mash, or jam the new AirPods into your ear canals. Proper positioning is obtained with just a light application of a finger (and you can check the quality of the seal with a new feature called Ear Tip Fit Test). The medium tips that were installed in the factory fit me nicely, but because all ears are different, Apple includes three more sizes in the retail box—including, for the first time, size XS.

In terms of convenience and thoughtful touches, the AirPods Pro 2 slap (as my kids would say), making the ownership experience second to none—awe-inspiring, in fact. Just as I remembered from the predecessor product (which debuted in late 2019), pairing couldn't be easier, especially with other Apple products. Place the brand-new buds near your iPhone and you can establish a Bluetooth link with one tap. Then, as you go about your business at home and at work, your desktop Mac, MacBook, iPad, and Apple TV will auto-detect your new IEMs and discreetly, without nagging, offer to connect.

Don't have (m)any Apple products? The new buds pair easily enough with an Android phone, but most of their extended features will then be limited or unavailable.

The synergy between the AirPods Pro 2 and the iPhone approaches seamlessness. For instance, if you open your phone's Settings app and the buds are within a foot or two, a contextual menu item pops up, giving you access to a range of tweakable features and functions. That menu disappears when the Pro 2s are no longer near. Elegant and effective.

More coolness: Placing the charging case close to your iPhone and flipping the lid brings up a battery-percentage window with readings for the case and the buds. Average battery life went up by a third with the new version, to six hours, and Apple says the battery in the dental-floss–looking case holds enough juice to fully charge the buds five times.

What else is new? Too much to cover, but here are five highlights.

The stalks protruding from the buds are now swipe-able volume controls. This works well unless your finger is wet from rain or perspiration.

You're less likely to lose the new AirPods, because the FindMy app will track them down even if they've fallen between the couch cushions or somehow ended up in the washing machine (footnote 3). And it's not only the charging case: Drop just one bud and you can find it with your phone, too. The built-in tracking technology works just like it does in an Apple AirTag.

An interactive ear test lets you tailor the Pro 2s' sound to your ears and compensate for hearing deficiencies. I heard no appreciable benefit from this feature, but a friend with mild hearing loss told me that for him, it restored "fullness" and "sparkle" to the music. Additionally, you can engage Personalized Spatial Audio after using your iPhone's TrueDepth camera to measure your face and each ear, yielding your unique earprint. (To assuage privacy concerns, Apple claims on its website that "Camera data ... is processed entirely on your device and images are not stored. Your personal profile for Spatial Audio will sync across your Apple devices using end-to-end encryption if you use iCloud and cannot be read by Apple.")

The company says the Pro 2s' active noise reduction is twice as effective. It's certainly worlds more effective than it is on my nine-year-old Bose QuietComfort 25 headphones.

The technology I toyed with most is Transparency Mode. It's not an Apple exclusive (Bose calls its implementation OpenAudio, Jabra calls it HearThrough, etc.), but the AirPods Pro 2 do it exceptionally well. With Transparency Mode, you can listen to your music while letting in environmental noise via the built-in microphones. It comes in handy, for instance, if you'd rather not get hit by the crosstown bus that you otherwise might not have heard coming. In this second-gen version of the feature, really loud noises are reduced in volume, and outside sounds no longer seem spacey and artificial, at least not to my ears. Hearing your own voice fed back to you remains slightly disorienting, perhaps because your brain struggles with the time disparity between the moment your words leave your lips and the moment the processed sound reaches your brain.

Listening
To take the sonic measure of the AirPods Pro 2, I listened using Roon, with my iPhone 14 Pro Max as a Roon endpoint. Other times, I connected to the Tidal app on my phone, and later to the Apple TV in the living room when I craved the final season of Dead to Me.

Overall, I found the music a bit more spacious with Transparency turned on, probably because a small portion of the room's environmental sound is added to the signal. Why this is noticeable even in a very quiet room at night, I can't really explain, except to say that other than anechoic chambers, even the most hushed rooms have a noisefloor. Mine hovers around 26dB, according to my SPL meter. Perhaps that's just enough to give music in Transparency Mode a hint of space.

Of course, the effect won't come close to the way sound behaves when it emanates from speakers or musical instruments in a room, but I did find it pleasing (and often exciting) that recordings were no longer so much in my head. Bands and orchestras seemed a little more spread out before me, even with the spatial audio feature turned off (more on that in a moment). The change was lifelike enough that on a few occasions, for a second or two, I got tricked into thinking that music was coming from my main system or from my four-piece Samsung HW-N950 soundbar. And once, a thunder-clap in a movie sounded real enough that I cast a startled look at the sky, only to find that no storm clouds were gathering.

Spatial audio is Apple's compressed version of surround sound, applied to just two channels. I liked it on one track, found it mildly annoying on the next, hated it on the third, and became smitten with it on the fourth. Back and forth it went, like plucking petals—I love it, I love it not, I love it. There was no rhyme or reason that I could discover, no obvious pattern, no eureka moment. Over time, the spatial trickery became an exhausting distraction, so I turned it off—on music. On movies, from Dolby Atmos blockbusters to black-and-white classics in mono, I enjoyed it. In a few films, like Darren Aronofsky's Requiem for a Dream on Amazon Prime Video, the dialog seemed a bit softer than I remembered from previous viewings (though still perfectly intelligible), while music and Foley sounds got pushed to the fore. But this effect was slight, and rare.

One more thing about Transparency Mode. It clamps down instantly on sudden peaks in your environment: barking dogs, screaming babies, squealing subway brakes, police sirens, the works. That's why Apple calls it Adaptive Transparency. This gave me the bright idea that the Pro 2s could be useful at too-loud concerts; perhaps they'd reduce the volume just before the live music reaches your ear canals. To test this, I played some Motörhead tracks on my stereo system at 95-plus decibels and listened via the new AirPods, with Adaptive Transparency engaged. Alas: The buds did little to lower the apparent volume—but they did make the music sound spacey and sharp, robbing it of bass and heft to boot. In fairness, Apple didn't intend for the AirPods Pro 2 to work as glorified earplugs. But maybe Team Cupertino could add such functionality in a firmware update (or more likely, equip a future generation of AirPods with it).

I've always found the upper midrange and lower treble to be on the abundant side on Apple devices, but the AirPods Pro 2 sound a bit more controlled and smoother than the Pro 1s do. Aside from piano, voices are (to my ears) the hardest thing for transducers to get right—and these IEMs are really good with voices. Leonard Cohen ("You Want It Darker"), Jarvis Cocker ("Room 29"), Eva Cassidy ("Waly Waly"), Dominique Fils-Aimé ("Birds"): all sounded clear, substantial, and pure. The Pro 2s ably conjured up vocalists drawing breaths and columns of air in motion. And even without aid from spatial audio or the transparency feature, I often got a good sense of the acoustic space the musicians were performing in, as on the Cassidy track.

Sometimes the sound was too smooth for my taste. Through the Pro 2s, the tin whistle on "Waly Waly" appeared rounded off, diminished in tonal clarity. The same was true for the guiro on "The Look of Love" by Saskia. The instrument lacked the trademark raspy sharpness that is rendered so holographically by my reference headphones, the Audeze LCD-4 and the HiFiMAN HE1000se. Not that those multi-kilobuck products are a reasonable benchmark by which to judge a pair of mass-produced plastic earbuds.

Both in quality and quantity, the AirPods Pro 2 produce bass that is a step up from the older model. They only faltered on recordings with extraheavy low notes—the kind of bass most often created with studio electronics pushing below 20Hz. When I played "Variations" by the Submotion Orchestra, or James Blake's "Limit to Your Love," or "You Should See Me in a Crown" by Billie Eilish, there was a raggedy fatness to those hyped bass notes, a lack of control, a bloated quality that made me want to skip to the next track. But these premium AirPods do regular deep bass without obvious faults or colorations.

Is this bud for you?
There's a Jekyll-and-Hyde quality to the AirPods Pro 2. I admire them for how well-thought-out they are, and I love how cleverly they integrate with other recent Apple products, especially iOS devices. They're chock-full of innovative features, some of which are meaningful (such as EQ that adapts to each user's hearing), and others that are more of the gee whiz variety (spatial audio). While these IEMs may not wow fussy audiophiles, they provide a lot of seriously wonderful entertainment, and I'll never look down my nose at that. For music performance, this latest generation is almost always pleasant and engaging. Bluetooth or no, sometimes they even touch excellence.

And yet, in another way, AirPods strike me as a raw deal. That's mainly because of the obsolescence that results from their glued-together housing, their lack of repairability, and most importantly, their limited lifecycle, especially of their built-in lithium-ion batteries (one in each bud plus one in the case).

It's not fair to only call Apple out for this; almost all wireless earbuds and most Bluetooth headphones have the same problem. The industry's dirty secret is that these products are just about disposable. If you charge your AirPods once a day (as students, office workers, and frequent travelers might), the buds' batteries will be on their last legs after 18 months, two years at best. That's based on Apple's claim that under optimal conditions, AirPods can be fully recharged about 500 times. After that, battery capacity goes downhill fast.

Sure, Apple says it will replace the AirPods Pro 2's batteries for $49, and that's great. But remember I said that one billion pairs of earbuds have been sold worldwide over the past five years? Roughly half of them are already dead—either tossed in the back of a junk drawer or buried in a landfill. It's a bad bargain for consumers and an alarming ecological burden. When the company finally stamps the Pro 2s as a legacy product (in four years? five? six?), consumers will no longer being able to replace those batteries. We'll be up the creek. Until they make their way back to an Apple store, ready to repeat the cycle.

By then, I will have owned my $350 Sennheiser HD 600 headphones for nearly 30 years. No batteries needed. Did I mention they sound unfailingly excellent? (Feel free to insert "Okay boomer" here if you're under 40.) Even if you don't care much about the environmental impact of quasi-disposable earbuds, their lack of residual value might give you pause. Virtually none of the gear we cover in Stereophile is destined for the landfill anytime soon. A lot of it will have two, three, four owners before it must be retired or rebuilt, often after decades. And at that point, it's typically still worth a non-negligible sum.

Without a doubt, the AirPods Pro 2 are a feat of design, innovation, and engineering. The increased fidelity of their music reproduction pushes them to the top of their class. But even at $249, a price that seems fair enough on its face, do they represent good value if you have to repurchase them every two or three years? Is that consistent with audiophiles'—your—sense of value? Does convenience trump sonics and environmental impact? I'm just asking the questions. The answers are up to each prospective buyer.

Speaking of questions: Beyond Apple, is there potential in this product category? I think there is. Many established hi-fi companies make travel-suitable noise-canceling headphones, and some of those products use consumer-replaceable batteries. Kudos. On the other hand, I know of no brand that has taken advantage of the recent Bluetooth 5.3 codec by building in support for lossless data. Which will be first?

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Footnote 1: I wrote "billion" hyperbolically. Then I looked it up. Guess how many wireless buds have been sold worldwide in the past five years alone? Yep, about a billion pairs. See bit.ly/3EjYxha.

Footnote 2: John Atkinson examined early versions of the AAC and aptX Bluetooth codecs in 2014. His conclusion was that the AAC codec "appears to attempt to preserve resolution at the expense of noise-floor modulation and the introduction of enharmonic spuriae (though it is fair to point out that the latter might be masked by the music). By contrast, aptX throws away absolute resolution in favor of preserving a random noise floor, presumably because this will be less annoying with music."

Footnote 3: See techgeekbase.com/airpods-survive-washing-machine. Try that with your DAC or integrated amplifier.