STEREO GUIDE verdict
+ precise, crisp bass
+ very well done calibration to the individual hearing
+ App also helps to find the right ear adapter by measurement
+ Up to 32 hours of playtime with recharging in case
- Inserting and wearing the relatively large earphones takes some getting used to
Sound: tonal balance / transparency9
Sound: Bass / Dynamics9.1
Ease-of-use / Connectivity9.4
With the two new fully wireless Bluetooth earbuds of the PerL series, Denon entered a technological field previously ignored by the major manufacturers: that of automatic hearing instrument measurement and adjustment of the sound without feedback from the user. Denon PerL (read the review) and PerL Pro offer a truly unique technology for this purpose, the so-called otoacoustic measurement of the auditory canals. However, it is not entirely new, as it was previously marketed under the name Nuratrue. Denon parent company Masimo acquired Nura some time ago, and now markets the fully wireless in-ears under the better-known Denon name.
The name PerL is short for“Personal Listening“. The flat design of the disc-shaped earbuds known from Nuratrue are similar for the PerL and PerL Pro models. Which raises the question: Is the Pro model, which costs almost twice as much, worth it in terms of sound and noise-cancelling compared to the standard PerL, which is only 200 euros cheaper?
Small, subtle technology differences
Both are fully wireless in-ear models (TWS) with built-in noise-canceling. However, the latter in particular is supposed to differ significantly between the PerL and the PerL Pro: the more expensive Pro has automatic adaptive noise cancelling. A higher-fidelity sound tuning should also justify the additional price.
It also fits that only the PerL Pro accepts the not yet so widespread standard aptX Lossless as Bluetooth codec. Add to that a longer battery life – 8 hours autonomously or a total of 32 hours with the case – and the gap to the inexpensive model is sufficiently maintained, at least in the technical spec sheet.
The PerL Pro’s transducer is an unusually large transducer capsule with a 10 millimeter diaphragm.
Individual, automatic adjustment
At the front of the Denon PerL Pro’s sound channel sits a small sensor that is supposed to receive so-called otoacoustic emissions. These vibrations reflected back from the ear provide information about the sound distribution within the ear canal and the frequency-dependent sensitivity of the ear. This procedure has been used for a long time in the fitting of hearing aids.
This makes perfect sense, especially for a high-quality in-ear, because the length and diameter of the ear canal and the position of the capsules, as well as the individual frequency-dependent sensitivity, can cause the sound impression to vary greatly from listener to listener. However, the technology called “AAT” (Masimo Adaptive Acoustic Technology), developed by Denon’s parent company Masimo, goes beyond the usual procedure used by hearing aid acousticians. It also assists in selecting the appropriate ear adapters and the best positioning of the Earbuds.
For the calibration process, you need a quiet environment and should place the in-ears as close to the ear canal as possible, as is usual with such models. The included rubber adapters in four different sizes as well as a foam adapter should suffice for this. To ensure that the rather large capsules sit well in the ear, two small rubber liners are optionally included. The whole thing sits surprisingly securely in the ear cup and should not fall out even during sports. The Denon PerL Pro is recommended for this anyway, because it meets the IPX4 protection class against splashing water. However, you should not sweat too much or immerse it in water.
Control, app and customization
As is usual with TWS, control is by touching the two housing shells. The function assignment can be individualized quite extensively. The Denon Headphones app is mandatory for this. Once you have it on your smartphone, there are numerous additional functions to discover in the app.
The software, which is available free of charge for iOS and Android devices, requires registration with an e-mail address and asks for things like age or gender. However, an Internet connection of the cell phone is not only required the first time. If you use your Bluetooth in-ear in the smartphone’s flight mode and only then start the app, the offline mode is suggested. If the app is already running before flight mode is set, it tries forever, but in vain, to find the PerL Pro.
Many functions only in the app
To individualize the adaptive ANC, you have to dive deeper into the app settings. The assignment of the touch-sensitive areas only allows switching between ANC and Social mode.
The slider for dosing the bass is also rather cryptically named “Immersion Mode” The surround sound button, which is exclusive to the PerL Pro. The Dirac Virtuo software behind it is supposed to avoid in-the-head localization and simulate another sound image. The Denon PerL Pro can play back immersive material like Dolby Atmos accordingly with its own 360-degree algorithm.
Overall, though, the Denon Headphones app is quite powerful. There is a manual equalizer and voice announcements, for example, when establishing the Bluetooth connection.
For loud listeners and classical music lovers
The volume limit for hearing protection can be activated in the app. Alternatively, you can activate a high-gain mode for high levels with tracks that were recorded too quietly or simply for more coarse dynamics. This could be especially interesting for those classical music listeners who have overly dynamically recorded albums with the softest pianissimo passages that cannot be sufficiently carried across the perception threshold with other in-ears.
This is how the Denon PerL Pro sounds
We cannot give a completely unambiguous answer to the question of sound quality – the combination of e individual ear calibration and manual equalizer allows a wide tonal variance.
In the first test run without AAT optimization, the Denon PerL Pro sounded somewhat less sober than its little brother, the PerL. Despite a slight effect sham in the form of a small extra portion of mica in the brilliance range, it basically stayed on the neutral side and refrained from overemphasizing certain frequency ranges. With a somewhat richer, more assertive low bass and silvery, but always clean highs, it announces higher demands in the gradation. You also don’t have to make any more annoying compromises when adjusting the equalizers and sliders.
The individual AAT adjustment did not bring quite as big a leap tonally as it had been the case with the inexpensive Denon PerL. Nevertheless, the Pro also extracted even more resolution and richness of color from the music once it was calibrated to the wearer’s hearing.
High-frequency impulses were a real joy after calibrating through it, and in some recordings it even delivered a cornucopia of treble detail without slipping into the sharp or annoying. To put it a bit bluntly: If the PerL sounds like a good hi-fi device, the PerL Pro with calibration already scratches at the high-end segment. In this way, it also loses the somewhat sober quality that is characteristic of it without individual adaptation, and which some listeners may even find boring.
Conclusion and alternatives to the Denon PerL Pro
The more expensive of the two new Denon TWS earbuds competes with the sonic luxury class of TWS: Sennheiser Momentum True Wireless, Sony WF-1000XM5 and Bowers & Wilkins Pi7 S2. The sound character of the Denon PerL Pro probably comes closest to the latter, at least when it is calibrated with AAT: High end with high resolution and pounding low bass with a trace of excess sound fascination. The B&W delivers a bit more treble shine and richer bass, the Denon is a touch more balanced and long-lasting.
Technical data Denon PerL Pro
- Manufacturer’s suggested retail price: 350 Euro
- Type: In-Ear
- Transducer principle: Dynamic
- Weight: 7.1 g (per earpiece), 47 g (case)
- Features: Bluetooth 5.0, aptX Lossless, adaptive noise-canceling, up to 32 hours of playtime with recharging in case, protected against splashing water according to IPX4
- More at: www.denon.com