Review: Denon PerL Earbuds

I’ve been down a sonic rabbit hole in which I wasn’t always sure where technology ended and human senses began. It came courtesy of Denon’s fascinating new earbuds, the PerL. I can’t even tell you what the PerL sound like; they’re designed to deliver custom sound tuned for each listener. What I can say is that Denon really has something here.

Personalized sound has become somewhat commonplace in wireless earbuds, but in my experience, it’s a lot of smoke and mirrors. In contrast, the audio profile the PerL created for me was pretty astounding, serving up sweet, intimate, and marvelously clear sound.

The earbuds are still a work in progress, with some questionable design choices and execution. But when the PerL get it right, there’s something magical happening that’s worth hearing for yourself.

The PerL’s journey began years ago with a company called Nura, which most recently had the NuraTrue earbuds. Like the NuraTrue, the PerL (short for Personal Listening) measure your hearing, then tailor a sound profile based on your ears' basic design and frequency sensitivities that adapt and change over time.

The earbuds make a good first impression. Disc-like endcaps look classy as you pop open their charging case, with a matte black finish that provides a minimalist aesthetic. Basic setup is also relatively simple thanks to the Denon app.

Once they’re in your ears, the design leaves something to be desired. Their bulbous exteriors look rather odd and stick out much more than micro-size rivals like the Samsung Galaxy Buds 2 Pro (9/10, WIRED Recommends) or Beats Studio Pro. Admittedly, the PerL’s disc-like shape isn’t any weirder than Apple’s golf tee aesthetic that has become the gold standard, but there’s no denying these things look and feel bulky.

The fit is also a mixed bag. The PerL utilize a two-piece ear tip system to account for their size, including an inner ear tip and a rubberized wing that fits into your outer ear. The combo provides a remarkably stable fit, but it also creates a plugged-up sensation when walking (sometimes called occlusion) and the wings tended to wear on my ears over time. These are far from the least comfortable buds I’ve tried, but I found myself thankful for relief after a couple of hours.

With earbuds designed around customization, I was hoping to find a variety of different wing options in the box, but the only other option is a sport-ready pair with an extended fin. I ended up using that second option with the fin sticking out, which mostly solved my comfort issues but also made the buds protrude all the more. There are plenty of ear tip sizes available, but Denon would be wise to offer more wing sizes, and/or slim down the buds in the next generation.

The best part about the PerL’s wafer-like end caps is all that real estate they provide for the touch controls, which proved both responsive and comprehensive (including volume control) once I dialed them in via the app. Interestingly, there are multiple tap controls unassigned by default, but I don’t mind taking the wheel to design my own layout.

There are two PerL models available, including the standard pair we’re reviewing here and a pricier Pro model, which adds extras like a multi-band EQ, multi-point pairing to connect two devices at a time, lossless audio with supported devices, and spatial audio, designed to create a 3D effect by virtualizing stereo sound.

They’ve also got an extra two hours of battery, with eight hours of playback time instead of six hours in the standard pair. Both pairs offer three extra charges in their respective charging cases.

That said, the cheaper model is pretty well stocked for its price point, with options like a volume limiter and gain enhancer (for low-volume audio sources), adjustable auto-pause and voice prompts, and mid-tier noise canceling and transparency mode. You’ll get better performance from the Pro model’s Adaptive noise canceling, but you’ll also pay a hefty premium to get there, and the regular model does a decent job with low-end rumbles like fans and traffic noise.

Once again, there are some execution issues at play with both pairs. Transparency mode sounds rather brittle and, more notably, the sound gets much quieter with transparency mode on, then ramps back up for ANC. This appears to be by design so you can better hear the world around you, but in practice it was annoying to jump back and forth, forcing me to crank the volume in transparency mode and then blasting my ears when I engaged noise canceling.

I also noticed some occasional rumbling noise that sounded like interference with ANC on, mostly apparent in the standard pair, though it’s not usually noticeable with audio playing.

When I say I can’t tell you what you’ll get with the PerL’s sound, I mean that in more ways than one. In three different profile adventures, across both the PerL and the PerL Pro, I got three different results, with the visual evidence to prove it (a little color pattern in the app shows you the hearing sensitivities measured).

The first version with the PerL Pro seemed like something of a misfire. The sound was different, and certainly better than the default, which seems almost purposely aimed at blandness, but it didn’t feel particularly tailored to my sonic vibe. The second try was better, serving up excellent clarity and detail, but still felt a little crisp and forward for my taste.

For whatever reason, it was with the more affordable model that I found blissful success. The first profile cooked up by the standard PerL earbuds felt like someone was in my head, crafting sound elements that “Ryan 3” would particularly enjoy. It might come as no surprise that the sound has a certain processed quality, what with it being processed before my eyes. Even so, it is one sweet ride.

Instruments seem to pop out of the ether, isolated so that each tone color is fully revealed, yet subtly presented. Horns are satiny and smooth, guitars and synths burn in their sonic corners with brilliantly colored timbres, and bass is full and balanced. All the different elements are married together in spectacular harmony.

Vocals are especially well reproduced with the PerL, offered with uncommon presence that lets you hear the full wash of reverb and each minute breath and detail with impressive precision. I don’t know how many times I’ve heard Brian Wilson’s “Feel Flows,” but it wasn’t until now that I realized he alternates “feel flows” with “feel goes” in the chorus. Similarly, Robert Smith’s breathy effects in “Close To Me” have never been more lively and, well, close to me.

I’ve never really bought into personalized sound profiles up until now, preferring to let the speakers do at least the majority of the work, and position my ears as semi-objective observers. Part of that is admittedly some insecurity; as someone who relies on their ears for a living, and for whom ear plugs have long been standard operating procedure, I don’t like to think about the ravages time takes on all of our hearing over time.

Denon’s PerL earbuds have made me a cautious convert. From the fit and design to the inconsistencies in the custom profiles, the PerL aren’t perfect, but they do feel like a confident step on the road toward something very exciting. If you’ve been wondering about personalized sound, I suggest you try a pair for yourself—you might find something your ears have been missing.