249 €

Review published:




per Side






16 Ohm











105 dB








Daily Life


18 - 22000 Hz


MEZE AUDIO is known for its over-ears, for which they have won countless awards over the years, but can they also produce in-ears?
Founded in 2011, the Romanian company has been conquering the IEM market since 2019 with its flagship Rai Penta hybrids, but has also experimented with wired in-ears before. However, this review is about the smaller brother, the Rai Solo with a dynamic driver. This one uses the so-called UNIFIED PISTONIC MOTION TECHNOLOGY, or UPM for short. Here, there are no wires on the membrane, but the membrane itself is conductive. This is intended to improve the vibration behaviour, as there is less irritation.


The Rai Solo is already a small work of art in its appearance and workmanship.
Here the years of development have paid off, because the final product is more than visible from an aesthetic and haptic point of view.
The ergonomics are also excellent, which makes it very comfortable to wear, no matter what the occasion or use.

As accessories we get a very robust hard case and a variety of different silicone tips (3 Soft-Silicone-Tips S, M, L | 3 Doubleflanged Tips S, M, L & 2 Long-Doubleflanged Tips M, L), but unfortunately no foam tips.

To be honest, I'm not the biggest fan of the included MMCX silver cable. It is of the more filigree kind, which is not the problem at first, but the metal reinforcements bother me. But the cable makes a harmonious overall impression together with the solo, even if you would have wished it a little softer and thicker.

The isolation is good and finds a good balance between reducing the outside noise but not the complete isolation.


Do I hear a difference through due UPM technology? Hm, not really, but this is very subjective and can sometimes have a positive placebo effect. In any case, the driver impresses with speed and firmness, which can certainly be attributed to this technology. In the end, it's more a question of the material used for the diaphragm. In the case of the Rai Solo, it is a multi-layer membrane with PET-PEI and an electrically conductive layer. The Solo is a rather neutral-bright tuned IEM, with a small, sometimes nasty peak around 3 and 5 kHz.

The bass is extremely tight and with a dry punch, but feels more at home in the mid-bass and does without a noteworthy sub-bass extension. As a result, the bass lacks a bit of authority, but can make up for this with very good detail reproduction and appealing texture. Sometimes it acts a bit anemic, but always convinces with precision. However, it will never swing the bass club, but will always act like a gentleman, holding back and contributing only the most necessary, which is also its strength and will make purists happy. In the sub-bass, however, there is room for improvement and I would like to see a bit more bite.

The midrange definitely has this bite. Due to their valley around 1 kHz and the following steep rise to 3 kHz they are tuned quite bright and vocal focused. The voices sometimes lack a bit of body, but still they have a very natural basic timbre. The mids can generally sound thinner due to the somewhat too dry and polite bass, but they score with clarity and crispness. I don't want to reproach the mids with boredom, because the transparency and separation is too good for that, but they definitely aren't the most lively ones, they rather go into the analytical direction. This is also ensured by the clear emphasis on the upper mids. This can even be quite exhausting and can slightly drift into the unnatural. Horns and guitars sometimes sound too aggressive, where the handle automatically goes to the volume control.

The lower trebles announce themselves with a 5 kHz peak for the first time and this peak has turned out to be a bit too brisk in combination with the somewhat set back mids. This robs the mids of their fullness even more and everything sounds less emotional and slightly sterile. After that, however, the highs calm down drastically and can stand out positively in high-end with very good extension and naturalness. No jingling, or exaggerations, but unexpectedly relaxed and high resolution without rubbing it in your face. In micro-, macro-, nano-, mega- and whatever-comes-next detail management should be a bit more present, but this criticism is more from my assumption the Rai Solo wants to put this in the foreground with its tonal alignment. There's certainly no lack of details, but with a more musical IEM my demand for more micro details would certainly be more restrained.

The strengths of the Rai Solo lie more in the soft and quiet tones, because with loaded music (e.g. rock) it sometimes gets a bit confusing with overlays, which is of course also very dependent on the respective mastering, it can become uncomfortable due to the already boosted mids. Nevertheless the stage is to be highlighted in its horizontal alignment. In the vertical as well as in the depth it is however less expansive.


Let's take a quick look at the weaknesses of the Rai solo. Personally too well-behaved bass, which lacks some dynamics and sub-expansion. Biting mids that want to be tamed and slight sibilant emphasis in the high frequencies. In addition, the Rai Solo doesn't forgive a bad recording quality, but this rather speaks for him and his more analytical demands.
Of course, the Rai Solo also has many positive arguments on its side, such as excellent transparency, precision and imaging. If you get a grip on the mids (EQ) and add one or two dB to the bass, you get a technically very sophisticated IEM, which is then also musically more convincing and can play out its strengths to the full.

Without any adjustments, the Rai Solo is a very agile IEM, which has a very good resolution, but is not one of the most musical representatives. On the other hand, it invites more analytical listening and can make friends of precision, voice reproduction and sharp 3D imaging happy. It also benefits from warmer sources. The workmanship is of the highest standard and leaves little to be desired both visually and ergonomically.



Here the processing plays a role and the usability of the scope of supply. Additionally the appearance, wearing comfort and robustness.

Here I evaluate for me subjectively the price/performance ratio - does not flow into the evaluation!

Z: No Brainer

A: money well spent

B: all right, you can do

C: gives better for less money

D: overpriced

E: collector's price

Daily life:
Here, I focus on the long-term audibility and whether I can hear it well out of the box. This is of course very subjective and therefore only a minimal deduction or bonus. 

(-0.1, 0, +0.1)


Rating in Letters

S: 9.5 - 10

A: 9.0 - 9.4​

B: 8.0 - 8.9​

C: 7.0 - 7.9

D: 6.0 - 6.9​
E: 5.0 - 5.9​

F: 0.0 - 4.9​


Second Opinion:


CHI-FIEAR © 2020 by David Hahn

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