Apple AirPods Pro Spatial Audio Update
Apple finally perfects the headphone surround sound experience, beating most $10,000 stereos.
HISTORY
Since the invention of stereo, engineers have been trying to create the perfect holographic sound. Getting that from just two speakers is theoretically simple, use a stereo microphone to capture a live performance and then play it back on a pair of speakers or headphones and the relationship between original event and recreated sound should be 1 to 1. In practice there are myriad of choke points and physical limitations which mean that the sound never gets captured faithfully and until recently the hardware to play back the sound was simply far below the accuracy level of human perception.
Speakers and headphones mostly suck under say $10,000. For the past 18 years, it was my 24/7 pursuit to search out and install the finest audio systems in the world. I’ve set up literally thousands of stereos of all variety in every conceivable room, as well as heard hundreds of pairs of headphones. The very best stereos I’ve created are so faithful to a live event that people will point into space at what they think is a vocalist standing holographically in front of them, or they will break down in tears at the feeling and colour of a bass guitar or saxophone. That’s what a real music-producing audio system can do. It’s not an exaggeration, but the vast majority of audiophiles and companies fail miserably to achieve it.
During Covid, my professional life changed dramatically. Gone was the daily demoing to customers and constant music on the world’s best stereos. I literally found myself in a career transition, wandering the streets trying to find some new life direction in Covid’s uncertain future. The problem was, I didn’t have any earbuds which meant I didn’t have music on my daily travels. Not good.
Having already tried almost all the bluetooth earbuds on the market I knew that it was unlikely to find something to meet my standards and being an Apple user I thought I’d check out the new (at the time) AirPods Pro. The previous Apple earbuds were absolute garbage, so bad that there were $29 wired earbuds that would easily beat any of their offerings. I was shocked to see the AirPods Pro frequency response graph on RTINGS.com:
RTINGS.com is not perfect. In my personal experience many of their graphs don’t match the actual sound of products I have heard or even sold, but when an audio professional sees a graph that looks like the one above, it piques your interest. I took a chance and bought a pair. Compared to my $75,000 stereo, it’s not a big expenditure for AirPods Pro and the promise of good music on the go.
SOUND
As stock, the graph above is very close to what the AirPods Pro sound like. Basically, the perfect sound is if the line is totally flat from left to right. All those squiggly areas are errors in how the sound is being reproduced.
The hump around “Low-Mid” means that men’s voices will sound slightly chesty and fuller than in real life. The dip at “Mid-Treble” means that there will be a little less punch to snare drums or bite on vocals. A bump or dip of 5dB (decibels) is very noticeable to an expert, but only mildly noticeable to the average user. Most people will not be able to describe those small errors in any meaningful way and even side by side against a “perfect” headphone equivalent I’d venture half of all people may say they’re the same.
My point is, out of the box, the AirPod Pros are functionally superb, in perhaps the top 1% of all headphones ever made. This is a huge change from Apple’s previous earbuds and a colossal bargain in the audio world. I was happy-enough walking around listening to them, pondering my future. But, there still was a problem…
SPATIAL AUDIO
Even the very best headphones at $2000 or $10,000 suffer from the problem of feeling “in-your-head”. Yes, great headphones can approximate a soundstage as if there was a band or orchestra on stage, but that feeling of being able to point at a performer in front of you like with speakers, simply does not exist on headphones. Earbuds tend to be worse. There are a lot of technical reasons why this is but the biggest one is the recordings themselves. Engineers don’t try to capture live spaces much anymore and in the case of pop music there is literally zero real spatial cue. They add it in with computers in studio based on what they feel like. If they want the guitar to move from left to right, they do it. Maybe they want a phase effect on a vocal so it sounds like it has no direction at all. In the case of mono, there is by definitely no spatial information in a song- ever.
When you listen to this kind of stuff on headphones it can have so many weird effects from song to song and album to album that, to a real speaker lover, it simply becomes grating. By contrast, put a stereo in a room and all these weird effects are in some degree mitigated because your brain merges the sounds and cues from the room with the sounds and cues on the song. There is not nearly the disconnect as on the vaccuum of headphones.
Long-hold the volume button in control centre to get to this screen.
Enter spatial audio. Because we only have two ears and we can’t physically put 7 or 11 extra speakers behind and around and above us, hardware and now computer wizards have tried to design an algorithm that approximates real space. Most of the early ones were horrible. Even surround sound I would argue is a blunt instrument compared to perfect stereo recording and playback simplicity. Let’s be honest, attempts at simulated spatial audio suck, until now…
Apple has done something amazing. I don’t know if they licensed this from someone or if they came up with it themselves. But they need to win a Grammy for technical achievement. For the first time in my life, I often reach for my AirPod Pros before I think of sitting down at my stereo. Spatial audio is the bridge that has made it possible.
Allow me to explain how it sounds and then I’ll go into what I think is going on. First of all, spatial audio seems to be intelligently applied depending on the how each song is mixed. You don’t need to buy tracks from Apple or have Dolby Atmos encoded tracks. Ironically the best effects come from mono songs. Remember, mono songs don’t have any imaging or space to them. It’s the same exact sound to both ears. The sense of space only comes from a purposeful difference of sound between each ears.
One of my favorite albums of all time is John Coltrane Soultrane. It’s from 1958 and it’s mono. Beatiful, lovely jazz and good tonal accuracy. The saxophone sounds like a saxophone. For such an early record, it is pretty well balanced. But there is no spatial information whatsoever. I actually use the song Good Bait to set up every stereo because it allows me to balance the volume of each speaker. If the sound from both is exactly the same, Mr. Coltrane’s sax will be hanging in space between the two speakers in perfect illusion. On headphones by contrast it sounds like it is somewhere between your eyes, thin and lifeless poking you irritatingly. However, turn on spatial audio and something magical happens. Somehow the sense of a room emerges. Not an overt echo or reverb in any way. Just more space. It’s beautiful. When I first turned it on I got emotional. I stopped walking. I thought, “holy shit, this is special.”
There are some other curious effects that are immediately noticeable too. The AirPods kind of have the feeling of a little too thunderous bass. Short of subwoofers and home theatre, music doesn’t really have super low bass so they always felt a little overblown to me. There was too much fireworks. With spatial audio enabled, the low bass seems slightly reduced and the mid-bass slightly increased. I suspect this is through some ingenious phase effects to double or expand certain bass frequencies (perhaps around 50Hz) to give more “body” for lack of a better word to the width of the sound. It is immediately noticeable Good Bait and to a slightly lesser extent, the less mono a track is. To me, this is the “sweetness” dial for sound and Apple has nailed it. This frequency and slight body activates the boogie factor, the soul of music. For people who are tuned into dancing or that pleasure centre, it makes you want to move. I frequently start air-drumming. It’s a wonderful thing, which previously I have never experienced on a pair of headphones.
The other curious thing is that whatever AI or algorithm they are using, it tends to leave well recorded tracks unmolested. Something like the Wagner’s Tannhauser by the Berlin Philharmonic is already one of the finest three-dimensional recordings ever made so it doesn’t need much. Switching spatial audio on and off has much less effect. Yet, it still manages to push this flawless recording over the bar into a level of realism that literally gives me shivers. It no longer is about two things in your ears making nice sounds, it becomes about you being in an environment of sound.
For the true highest end audiophiles, there are a few little niggles. The very highest highs are slightly rolled off (say 2dB perhaps at 14Khz). Most people are deaf here anyway, and because they are ever so slightly toned, you can listen for 4 or 5 hours with zero fatigue. Second, I detect ever-so-faint compression artifacts in the high treble range which almost subconsciously register. Again, 99.9% of people will not be able to pick this out. It’s a slightly digititis that only mega-bucks vinyl lovers will understand.
Of course, it can’t go without mentioning that the AirPods are superbly built and offer a ton of other functionality. Currently if you’re an Apple user you will be pleasantly surprised to use all the convenience features that come free with them. I’ll review the Voice Isolation feature for heavy phone-talkers in another review. It’s also a revolution of function.
SETTINGS
One final note about settings. As standard, Apple thinks that as you turn your head, the sound should stay focused to where your head started. I think this is a big mistake. After 5 minutes of walking and looking around, the feeling is that the voice of a singer, for example, is zooming back and forth between your ears. I get it, it’s supposed to approximate a person or band being in a fixed axis in front of you. But it doesn’t really work, especially when you’re out in the middle of the street and moving various directions. The brain just can’t square the two realities and the tech isn’t fast enough or pin-point enough to overcome it.
While sitting it’s a lot better, but if you’re sitting, then you’re not moving so who cares. They should turn it off for music for sure. For movies it’s more effective. If you’re walking around your house watching a YouTube video it kind of keeps the person talking locked in one direction. I still turned it off. Maybe they’ll improve it later. The setting is under Accessibility: AirPods: Spatial Audio Head Tracking. Choose Off.
CONCLUSION
I think I know how the horse-buggy makers felt when Henry Ford came along. Simply, the AirPods Pro with spatial audio is the most important audio product of the last 50 years and encapsulates what I’ve had to manually do for decades at considerable cost and effort.
For $249 AirPods Pro slaughters 99.99% of all headphones ever made. Unless you are truly a trained audio engineer or golden-ear audiophile (not golden cheque book) you are not going to be able to construct a more tonally accurate stereo than the AirPods Pro under $10,000. Yes, not having something in your ears is great and being able to have music on for dancing or while other people are around will mean that stereos are never obsolete, but for private listening, this is the top of the heap.
I dare say that Apple has also unwittingly created the universal studio recording and mastering reference device. If you want to hear what your mix sounds like, really sounds like, forget everything else. Any place on earth, with just a bounce down to your phone you can reliably mix at pro levels. Or record on them and then “master” on the phone. It’s insane.
My only fear is that at some point they will stupidly tweak the equalization or spatial algorithm, or the battery will wear out, or they will discontinue them. To paraphrase William Congreve: “AirPods Pro with spatial audio hath charms to soothe the savage breast, to soften rocks, or bend a knotted oak.” They’re divine. If you, or anyone in your life, uses an iPhone and likes music, you owe it to yourself to buy one or more pairs of AirPods Pro.
PRICE
$249.00 USD
AVAILABILITY
THE RATING
10/10 Absolute
10/10 Relative
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