Denon Perl Pro

Here at Gamereactor we often complain that not many in-ears, not even the expensive ones, support AptX HD - or at least I do. But every once in a while there's a positive surprise. Because after it was announced two years ago, we finally have a bit of a breakthrough.

Denon Perl Pro doesn't just come with AptX HD, but actually with AptX Lossless, which is twice as good, delivering a 1.2 Mbps bitrate, and significantly more than LDAC's 990 Kbps. This is almost the same bit rate as CD quality, i.e. 16-bit/44.1 kHz. As with AptX HD, you get support for 24-bit music playback, which at 192 kHz sample rate requires 9.2 Mbps. So there's still some way to go, but we've come a long way - remember that regular AptX, AAC and SBC are around 350 Kbps or less. That's almost 30 times higher bit-rate, and you can hear it.



The unit itself is relatively standard, except that the outside is covered with a massive round plate with a Denon logo, and while I understand that it is meant to house the DSP, it can seem a bit excessive.

But what Denon would probably rather we write about is their personalised sound, Denon Sound Master Tuning, formerly Masimo Adaptive Acoustic Technology (AAT), formerly Nura. This is simply because Nura invented the technology, was acquired by the group that owns Denon, who in turn decided it was probably best to keep the Denon name in focus - from what I can piece together. Denon Perl looks a lot like the original Nura Truebuds. The technology works by sending sound waves to your eardrum, and based on the reflected sound, it can then work out how you hear and adjust the sound through compensation. My results show that I am extremely sensitive in the bass and slightly sensitive in the treble. I've only been frequency-measured before, and I could still hear well above 20 kHz, which is good considering my age and love of hard rock.



And here comes a scratch in the armour, because the app requires the creation of another account with full login and everything. And I don't get it, because if you want to use it again another time, you'll probably have to recalibrate everything anyway, and I have to admit that I just don't want any more apps, especially those that require a login. Stop it. There is no justification for yet another company to receive and store my information forever. On the other hand, the app is pretty good, it's intuitive, and there has obviously been a user interface designer involved.

It's demanding, of course, and they "only" last eight hours, but there's an additional 32 hours of battery life in the case - and that's more than enough for me. There's also spacious sound, Spatial Audio - in the form of Dirac's Virtuo. Some may prefer Dolby Atmos, but as I listen to a lot of live recorded audio, I never run with any form of virtual surround, it's a feature I find very hard to believe is a real sought-after feature for the majority of consumers.



The device itself is IPX4 certified, weighs 8.6 grams each, has three microphones in each part, plus a bone conductor sensor and the moving part, similar to a speaker unit, is a triple titanium layer. Where it stands out, however, is the fit, which comes in four sizes, as well as a foam tip and "wings". Normally, with 99% of all in-ears we test, the medium size that comes with them fits fine, but here I had to do a little trial and error, because even though they seemed to fit fine, I experienced a lot of microphonics, i.e. when I stepped down, the vibrations from my leg travelled all the way to my skull and into the units, which gave a very unpleasant "plop" sound, similar to when you brutally rip a plug out of an amplifier. So for some reason, the tips here are either different in size or material, and experimentation is required. In addition, they are relatively large, with a sort of umbrella at the back sticking out of the ear. It is an advantage that you can easily see which is right and left as the Denon logo can only face one way, but on the other hand, I prefer not to indicate, which brand I use. Still, the case comes with wireless charging, thankfully!

The whole thing costs £300. That's a lot, but on paper you also get the best sound transmission on the market and really good noise reduction. So does it work? Yes, I think it does. I can't help but notice that the sound when the "personalised sound" is turned off is compressed and coarser, but it's actually worse than other in-ears in the same price range. On the other hand, when it's switched on, the sound is fantastic, but I'm left with the feeling that the difference between regular and "personalised sound" has been artificially increased.

The noise reduction works and the near-lossless transfer means that with a high-res streaming subscription, you actually get value for money. The sound is slightly bright, but with a large holographic soundstage, depth, punch and accurate bass, and really good resolution. We're not at IEM level, but it's getting there.
So if you can live with the slightly funny fit and the protruding toadstool of a design, you're in for a wireless experience of the very best calibre. But don't bother registering for the app...