Sources: iPhone XS-Max, 16/44 WAV files (CD rips).
Disclaimer: I purchased the Airpods Pro from Apple at full price. In this mini-review I'll use my own definitions for 'Earbud', 'Earphone', 'IEM', etc.
IEM: The most common of hi-fi earphones, these sell for as little as $15 and as much as $5000 USD or more. Key features of the IEM (In-Ear Monitor") are a nozzle projecting from the body, with a choice of interchangeable eartips to mount on that nozzle. These eartips are inserted well into the ear canal to 1) Ensure a stable fit, and 2) To obtain a good seal against the ear canal walls for best bass response.
The Airpods Pro are not IEMs.
Earbud: Any earphone (not always hi-fi) that fits its drivers inside the ears somewhere, as opposed to headphones, which sit on or around the ears.
The original Airpods were a higher-quality type of earbud that focused its sound through a narrow opening in the earbud, rather than across a wide surface as the older round earbuds were designed to do. Those Airpods (and the Earpods before them) were able to achieve much better bass response than the older round earbuds, by getting most of their sound much closer to the ear canals.
The newer Airpods Pro attempt to do even better by moving the sound closer yet, by using interchangeable eartips that have narrower openings (like IEMs), but are mounted on the earbud body rather than on a nozzle as the IEMs are. The Airpods Pro do this very well in my experience, where the middle-size eartips fit up against my ear canals, but do not penetrate noticeably. With this design I have good comfort and a secure fit, and most important - a full-range sound with good bass response.
Describing the Airpods Pro sound in hi-fi terms is really tricky, because you'll need to get a perfect (or nearly so) fit so that the bass response is properly balanced to the midrange and treble. NOTE: When I tested my fit using the Ear Tip Fit Test in the iPhone's Bluetooth settings, the results were mixed - sometimes OK on the Left and NOT OK on the Right, or vice-versa. Don't be misled by these results, since an intermittent "Good Fit" might actually be perfect, as it is in my case. NOTE: 'Intermittent' as in an electrical connection is usually a bad thing, but 'intermittent' here is just the 'Fit' report result, which has no requirement for exactness.
One of the more difficult deep-bass sounds I have for headphones to reproduce accurately is the contrabassoon(?) that weighs in around 10:30 of Beethoven's 9th Symphony 4th Movement, performed by Georg Solti and the Chicago Symphony in 1972. The Airpods Pro play this with very good weight and detail. Another track that has strong bass impacts in the opening seconds is Trombone Shorty's Backatown. The bass notes here are played back with uneven weight by many headphones, depending on the frequencies for each tone. The Airpods Pro play these notes evenly and convincingly.
The Airpods Pro midrange will probably vary less among different users than the bass and treble, for various reasons, but the crucial factor is getting accurate tonality of instruments and voices. In my listening thus far (6 days), the tonality has been spot-on. Reviews often note how well or how poorly a headphone sounds with good quality recordings versus poor quality recordings. I haven't experienced anything different in that respect with the Airpods Pro compared to my other headphones, and that for me is a good indicator that this earphone is a high fidelity product - assuming of course a good quality source, good recordings, and a reliable and clean Bluetooth connection.
Treble is the most difficult part of the sound spectrum to analyze, and if you have a look through some of the Innerfidelity test charts, you'll see why. Those very ragged lines representing the treble measurements stand in stark contrast to the much smoother parts of those lines that represent the midrange and bass responses. Given my experience with many quality IEMs to date, I'm confident that the Airpods Pro treble is either pretty smooth and reasonably neutral, or smooth enough in the neutral ballpark to be easily treatable with the iPhones' settings, or whatever the Android phones have to offer.
Summarizing the above, the Airpods Pro may be a great Earphone, at full price, for users whose requirements are similar to mine: High comfort with no significant penetration of the ear canals; A good frequency response or one that's easily addressable with an effective EQ; Price that suits these factors plus the convenience factors.
Disclaimer: I purchased the Airpods Pro from Apple at full price. In this mini-review I'll use my own definitions for 'Earbud', 'Earphone', 'IEM', etc.
IEM: The most common of hi-fi earphones, these sell for as little as $15 and as much as $5000 USD or more. Key features of the IEM (In-Ear Monitor") are a nozzle projecting from the body, with a choice of interchangeable eartips to mount on that nozzle. These eartips are inserted well into the ear canal to 1) Ensure a stable fit, and 2) To obtain a good seal against the ear canal walls for best bass response.
The Airpods Pro are not IEMs.
Earbud: Any earphone (not always hi-fi) that fits its drivers inside the ears somewhere, as opposed to headphones, which sit on or around the ears.
The original Airpods were a higher-quality type of earbud that focused its sound through a narrow opening in the earbud, rather than across a wide surface as the older round earbuds were designed to do. Those Airpods (and the Earpods before them) were able to achieve much better bass response than the older round earbuds, by getting most of their sound much closer to the ear canals.
The newer Airpods Pro attempt to do even better by moving the sound closer yet, by using interchangeable eartips that have narrower openings (like IEMs), but are mounted on the earbud body rather than on a nozzle as the IEMs are. The Airpods Pro do this very well in my experience, where the middle-size eartips fit up against my ear canals, but do not penetrate noticeably. With this design I have good comfort and a secure fit, and most important - a full-range sound with good bass response.
Describing the Airpods Pro sound in hi-fi terms is really tricky, because you'll need to get a perfect (or nearly so) fit so that the bass response is properly balanced to the midrange and treble. NOTE: When I tested my fit using the Ear Tip Fit Test in the iPhone's Bluetooth settings, the results were mixed - sometimes OK on the Left and NOT OK on the Right, or vice-versa. Don't be misled by these results, since an intermittent "Good Fit" might actually be perfect, as it is in my case. NOTE: 'Intermittent' as in an electrical connection is usually a bad thing, but 'intermittent' here is just the 'Fit' report result, which has no requirement for exactness.
One of the more difficult deep-bass sounds I have for headphones to reproduce accurately is the contrabassoon(?) that weighs in around 10:30 of Beethoven's 9th Symphony 4th Movement, performed by Georg Solti and the Chicago Symphony in 1972. The Airpods Pro play this with very good weight and detail. Another track that has strong bass impacts in the opening seconds is Trombone Shorty's Backatown. The bass notes here are played back with uneven weight by many headphones, depending on the frequencies for each tone. The Airpods Pro play these notes evenly and convincingly.
The Airpods Pro midrange will probably vary less among different users than the bass and treble, for various reasons, but the crucial factor is getting accurate tonality of instruments and voices. In my listening thus far (6 days), the tonality has been spot-on. Reviews often note how well or how poorly a headphone sounds with good quality recordings versus poor quality recordings. I haven't experienced anything different in that respect with the Airpods Pro compared to my other headphones, and that for me is a good indicator that this earphone is a high fidelity product - assuming of course a good quality source, good recordings, and a reliable and clean Bluetooth connection.
Treble is the most difficult part of the sound spectrum to analyze, and if you have a look through some of the Innerfidelity test charts, you'll see why. Those very ragged lines representing the treble measurements stand in stark contrast to the much smoother parts of those lines that represent the midrange and bass responses. Given my experience with many quality IEMs to date, I'm confident that the Airpods Pro treble is either pretty smooth and reasonably neutral, or smooth enough in the neutral ballpark to be easily treatable with the iPhones' settings, or whatever the Android phones have to offer.
Summarizing the above, the Airpods Pro may be a great Earphone, at full price, for users whose requirements are similar to mine: High comfort with no significant penetration of the ear canals; A good frequency response or one that's easily addressable with an effective EQ; Price that suits these factors plus the convenience factors.
