Review: Ultimate Ears Pro UE Premier

In-ear monitors are exceptionally difficult to make. You have to take drivers (speakers), and miniaturize them so they can fit into the little cup of your ear while retaining the highest quality sound. While your average consumer earbuds like Apple’s AirPods Pro or Bose’s QuietComfort Earbuds II will likely have a single driver per ear, high-end in-ears may have three, four, eight, or maybe more.

Ultimate Ears Pro’s new UE Premier have 21—yes, 21—tiny speakers per ear. They sound so good it feels like I’m listening to music with new ears, and it has me contemplating some weird existential questions.

If you’ve ever seen your favorite musicians perform live, chances are they were wearing in-ear monitors, or IEMs. These custom-molded headphones fit only the person they were made for, injecting music directly into their ear holes. Producers, sound techs, and audiophiles love them, as they are designed to present detailed sound while still affording maximum mobility. UE Pro, the professional subdivision of the larger Ultimate Ears brand, is a pioneer of IEMs—making the first pair for Alex Van Halen—and its latest set represents an insane feat of engineering.

Photograph: Ultimate Ears Pro

Because no two ears are the same size or shape (even my right and left ears are massively different), buying IEMs starts with getting an impression made of your ears. For most of us, that means a trip to an audiologist who will fill your ears with a silicone goop to get a high-resolution representation of each ear, all the way down to the second bend in your ear canals. Expect to pay $50 to $100 for this service. If you happen to be near the Ultimate Ears Pro office in Hollywood (or you find the company's booth at a trade show), you may be able to have your ears laser-scanned, which is just as accurate and is a good deal quicker. Those impressions will be sent to the Ultimate Ears Pro factory in Irvine, California, where an engineer will digitally polish and retouch a scan of your impressions before having the shell 3D-printed with resin. Engineers then glue each of the drivers into the shell, one at a time, before sealing it up. I had this done about four years ago and made a video of the whole process.

Photograph: Ultimate Ears Pro

Peeking inside the Premiers is like looking at some kind of cybernetic device from John Connor’s future. The drivers include, from low to high, four dedicated sub woofers, eight drivers to cover the middle-low range, four midrange drivers, four high-frequency super tweeters, and one proprietary True Tone driver designed to capture any upper harmonics and overtones present in the mix. There’s also a five-way passive crossover that directs each tone coming in to the best driver for it. The Premier are capable of delivering frequencies as low as 5 Hz and as high as 40,000 Hz, both extremes being beyond the range of the human ear.

All that componentry adds up: These headphones cost $3,000 a pair. Ultimate Ears Pro is marketing the Premiers toward, well, pretty much anybody who can afford them. That includes musicians who perform in front of packed crowds, studio engineers, composers, and just plain old audiophiles with disposable income. Traditionally UE Pro has targeted different products to different demographics, so it’s interesting to see it take a sort of “one ring to rule them all” approach here. I actually already had a pair of the company’s last flagship IEMs, the highly regarded UE Live (eight drivers per ear, $2,299), which I’ve used obsessively for the past four years, so I was able to do a bunch of one-to-one comparisons using a variety of music players and music sources.

The first thing I noticed is that the Premiers are larger than the Lives. The faceplate of the Live lines up with the plane of my outer ear, while the Premiers stick out ever so slightly. They feel a bit tighter within my ear, too, and it took me a week or two to get used to them. They don’t have active noise canceling, but they fit so snugly that they block out roughly 26 decibels of ambient sound, a noise level equivalent to the murmur of an open-plan office. You will not have any trouble hearing audio over the roar of a plane, or really anything else. The Premiers have three holes in them: a main channel for delivering sound, a small hole next to it that helps deliver additional frequencies, and a tiny hole toward the top of your ear (by the helical crus) which is exclusively used to vent pressure (better for your eardrums and for bass performance, almost like open back headphones).

The Premiers come with a swappable cable with UE Pro’s proprietary IPX67 connectors. That means you can replace a damaged cable, swap in a cable with a mic to use the earphones for calls, or even plug in a Bluetooth cable that lets you run them wirelessly. You also get an engraved carrying case and a cleaning tool. For my custom faceplate I chose a multicolor splash, but wood, mother of pearl, and carbon fiber are all options.

Photograph: Ultimate Ears Pro

It doesn’t really matter how many drivers you cram into headphones if they don’t sound good. Fortunately, the Premiers offer absolutely breathtaking soundscapes. Music comes through so full, and so rich. The separation between different instruments is immaculate. On lower-quality headphones or speakers, you sometimes hear some instruments duck down in volume to make space for others. In the Premiers, each instrument seems to occupy its own space, and everything seems to be in perfect balance.

The bass has plenty of power and fullness, but it’s incredibly clean and distortion-free. The highs are pure and don’t have any unpleasant piercing shrillness. That’s something you can find in a fair amount of cheaper headphones, but where the Premiers really set themselves apart is in the middle. The mids shine through like I’ve never heard in anything short of a well-engineered live show. This is especially significant for vocals, which manage to stay perfectly prominent, even against heavy instrumentation.

There is also just a stunning amount of detail. Listening to “Pick Up Your Feelings,” by Jazmine Sullivan, I could hear the quality of the wood in the drums, and there’s more nuance in her vocal runs. I could hear the little rasp in her voice when she belts. Listening to Lil Yachty’s “Running Out of Time,” I heard these gorgeous, subtle harmonics in the bass guitar that I’d never noticed before. I’ve listened to “Nude” by Radiohead hundreds of times, but playing it back through these earphones, I heard details in the choral and orchestral sections that I’ve never heard before. Compared to the UE Live, the sound is warmer, like I’m being serenaded in a room made of rich, soft wood. I could detect more nuances in the middles of Thom Yorke’s voice; he sounds fuller, like there's more of him somehow. The bass on the track feels prominent but doesn't overpower anything else. It has a juicy quality to it that's very satisfying. The soundstage is a bit wider, so it feels like it fills the "room" better.

Impressed by the accuracy of the Premiers, I decided to take the opportunity to settle some sound format debates, at least for myself. The first was listening to standard, high-quality streaming music on Spotify and YouTube Music versus lossless Ultra HD files from Amazon Music. Those Ultra HD files encoded with the Free Lossless Audio Codec instantly sounded fuller and richer, not surprisingly, but the Premiers give the files' higher bitrates a real platform to shine. I then pitted those FLAC files against Tidal’s controversial MQA (Master Quality Authenticated) format. Frankly, I expected them to sound more or less the same as the Ultra HD files, but I preferred Amazon's FLACs almost across the board. Not only do FLAC files almost always have more volume, they sound cleaner to me, with better separation between instruments.

I also toyed around with alternative formats like Dolby Atmos and 360 Reality Audio. It was fun to experiment with their immersive effects, but I noticed they suffered from a significant reduction in audio quality. When things get spatial, there's an instant loss in richness to the vocals and a thinning of the bass. The difference is even more obvious if the FLAC is encoded higher than 24 bits at 48 KHz. That being said, I spent one evening lying on my couch and listening to the new Sigur Rós album, Átta, in Atmos, and while I was cold sober it definitely felt like I was tripping on something. The spatial audio made it feel like I was floating through space with these melodies coming from every direction.

I want to emphasize that the quality of the recording and mastering is far more important than the file type or bitrate. There are some albums you can download as 24-bit, 192-kHz lossless FLAC files that don’t sound half as good as a well-recorded and well-mastered album released at 16-bit, 44.1 kHz (aka “CD quality”). Still, these headphones are precise enough to allow you to hear the difference between high quality and ultra-high quality, and I believe they will satisfy even the most persnickety of audiophiles—if anything can.

When I started testing the Premiers, I just plugged them into my USB-C adapter for my Google Pixel 7 Pro and fired up my standard audio test playlist. I was just listening to plain old YouTube Music at first, and instantly everything sounded better than I’d ever heard it coming out of my phone. The Premiers pump out significantly more volume than the UE Lives (which had plenty of power themselves), and I found myself turning the volume down to around 30 percent. Fearing I was wasting these buds on low-quality music—YouTube Music tops out at a pretty low bitrate and doesn’t offer lossless listening options—I subscribed to Amazon Music and Tidal for hi-res testing.

I also lined up other higher-quality devices to test with. First up was my 2022 MacBook Pro. Like my phone, it’s capable of outputting 24-bit, 48-kHz audio, but the amp on the laptop is just so much better and cleaner than what’s on my phone—not to mention dongle-free. I instantly heard nuance and detail in some of my favorite songs that I’d never heard before: little catch-breaths from singers, barely audible scrapes of calloused fingers on guitar strings.

The next upgrade was to the Fiio M11S, a $500 entry-level portable hi-res music player—basically a Zune on steroids. The first time I queued up Prince’s “Purple Rain” at 24-bit, 192 kHz, I gasped. It felt like a sonic resurrection. The Fiio instantly became my constant companion, but I wanted to go one step further. So for home use, I started using a Marantz SACD 30n, a $3,000 audiophile-grade digital source player capable of going up to 24-bit and 384 kHz. The combination of that machine and these headphones sounds brilliantly full, realistic, and sublime.

Photograph: Ultimate Ears Pro

The Premiers have been glued to my ears for more than a month now. I don’t know if I’ve ever spent more time listening to music than I have during this test period. It’s incredibly addictive. Every time I put them on, I think, “Ooh, I wonder what this album is going to sound like through them!”

There are only a couple of things I can ding them on. The first is the price. At $3,000 they obviously price out the general consumer. That said, it’s not an insane price for the audiophile market or other audio professionals. There are more expensive flagship IEMs out there, and while there’s no accounting for taste, you’d be hard-pressed to find a set at any price that sounds this good.

The other thing is that Ultimate Ears Pro doesn’t currently have a Bluetooth option worthy of the level of sound quality the Premiers deliver. UE Pro’s current Bluetooth cable ($100, and sold separately) is pretty dated; it tops out at Bluetooth 4.1 and doesn’t support any of the new lossless Bluetooth protocols. Despite that, music actually still sounds great through them, certainly better than any other Bluetooth earbuds I’ve used. And I can't really ding the Premiers for this, though, since the Bluetooth cable is an accessory, and most IEMs don't even have the option for Bluetooth. (UE Pro told me it’s currently working on a new Bluetooth option which will be available in a month or so. I will update this part of the review with details once I’ve tried it.)

Lastly, there’s something about these that actually make me feel kind of lonely. I can’t tell you how many times I’ve wanted to put these things in a friend’s ears and say, “You’ve gotta hear this!” then play them their favorite song or album, but I can’t. While it’s kind of cool knowing that these things fit you and you alone, it’s sad that you can’t share this magical experience with anyone.

Nitpicks aside, if you have the money and are interested in owning audiophile-caliber in-ear monitors, I consider these to be the new high-water mark. The other day I listened to a hi-res version of Jimi Hendrix’s Live at the Fillmore East 1970 through the Marantz, and I realized that it was almost certainly the closest I'd ever get to hearing what my rock hero sounded like live. I caught myself tearing up when I heard some little quivers in Otis Redding’s voice for the first time in “Dock of the Bay,” remastered at 24-bit, 192 kHz, and when I heard how organic and alive Yo-Yo Ma’s cello sounded in a recent solo recording, I felt like I was sitting alone in a room with him as he played. I’ve never felt myself transported by music like this while sitting in the comfort of my own home. If you can afford the ticket, there’s a whole musical voyage waiting for you.