If you're looking for a clear, energetic, open sounding IEM with strong technical foundations and a touch brighter than reference tuning then the Solo will provide fantastic value for money. If you own a warm DAP or source or are willing to EQ you can shift its signature easily into a slightly warm and fuller sounding reference IEM without loosing its clarity and energy.
- Very good soundstage and imaging
- Well controlled and very detailed bass
- Clear, articulate mids with very good bite
- Energetic yet smooth treble with good extension
- Very good response to EQ if need be
- Outstanding build quality
- Bass might lack impact for some
- Upper mids might have too much bite (can be EQ’ed)
Manufacturer’s website : https://mezeaudio.com/products/rai-solo
Price : 249$
Fit, Build & Isolation
The Solo shell looks identical to its bigger brother the Penta, the only difference being color. It’s compact and lightweight which contributes to excellent comfort and the fit is top tier as far as universal goes. This is no small aspect of an IEM for every day use. The build is superb with very tight tolerances and immaculate finish which punches well above its price range. The Solo look sturdy (up to the color coded metal nozzle).
Isolation is good, and much better than the Penta, probably due to a smaller vent and the choice of stainless steel versus the CNC Alluminium of the Penta.
Meze Audio is not a new comer, founded by industrial designer Antonio Meze in 2011 in Romania, it became widely known to the audiophile community with the award winning Meze 99 Classics. I purchased a set and it’s one of my favorites headphones regardless of price, with great value for money.
Since then, Meze move on to conquer the flagship headphones and IEM category with the highly acclaimed Empyrean and the Solo’s bigger brother the Rai Penta. While the Penta and Solo share identical shells aside from color, Meze chose a single dynamic driver for the Solo’s architecture versus the 4 BA and 1 dynamic of the Penta.
For the Solo Meze keeps innovation going with what they call Unified Pistonic Motion (UPM)
Meze writes “In a traditional electrodynamic driver the voice coil lead wires are glued to the back side of the thin membrane. This is the major factor of the unbalanced vibration. The new UPM driver eliminates this inconvenience by using a totally different approach: the membrane itself is electrically conductive and, therefore, no wires are attached to the diaphragm. The result is a symmetric pistonic motion through its entire movement, without disturbance from the unbalance created by wires.”
Since I am a big fan of single dynamic driver in terms of coherence, physicality of the bass and edge in timbre accuracy I was curious about the tuning of the Solo, would it be the IEM counterpart of the Meze 99? Or would it be something entirely different?
The Solo is clear sounding, with very good soundstage and imaging and its tuning is quite reference with a significant touch of mids forwardness. It boast well controlled and very detailed bass, clear articulate mids with excellent bite and energetic but smooth treble with good extension.
The Solo is characterized by well textured and highly detailed bass, more than a hard hitting, punchy bass. It’s a refined bass presentation rather than a full on bass-head experience.
Sub bass extension and presence is fair but nothing to rave about either especially for a dynamic driver. Sub bass is more heard than felt on most tracks. Only the most sub bass heavy tracks like Aphex Twins “Ageispolis” is the sub bass satisfyingly present but it’s a track that’s on the far end of the scale. Other sub bass test tracks like Sohn’s “Falling” or Alice Jemima “Liquorice” are a bit disappointing. Things are a bit different with the AAW Capri DAC/cable for the iPhone with a less neutral source the Solo sounds fuller and has more impact. I actually like the Capri’s presentation better than the LPGT without any EQ with the Solo. As we’ll see later on in this review, in my opinion the Solo matches better with a warmer source than a pure neutral one without EQ.
Solo’s mid bass is tuned a bit similarly, but there is a bit more presence and heft to percussions in Manu Katché “Keep on trippin’ ” and José James “Better of dead”. The Solo convey a nice rythmic baseline but more impressively the level is very high with a very articulate presentation. The Solo’s bass has good control in all circumstances and fair speed for a dynamic.
This makes up for a rather reference bass tuning that a fun one, and again switching to the AAW Capri there is a bit more impact and presence which sounded more satisfying to me.
The Solo’s mids are clear, articulate with very good separation and air, timbre is accurate and the presentation is forward. The Solo emphasizes lead instruments and vocals with a focus on the upper mids section.
Lower mids are not thin by any standards, but do take a back seat to the more prominent upper mids. The mids are full bodied, but neither thick nor warm. Vocals are clear and there are a lot of nuances conveyed with the Solo, this is where it punches well above comparably priced IEMs. On the flipside, out of the dead neutral Lotoo PAW Gold Touch Male vocals do lack a bit of power and sound a bit higher pitched than neutral. This being said, given it’s signature the Solo can be EQ’ed easily with great results without loosing clarity. Switching to the less neutral but excellent value for money AAW Capri DAC/cable out of the iPhone provides a bit more lower mids and is fairly similar to using EQ on the LPGT.
Upper mids are significantly forward, and the Solo therefore has limited depth to its soundstage, lead instruments as well as singer are not far away from you. Also, the Solo has a significant amount of bite, cymbals have great sizzle, snare drums are very crisp and electric guitar remarkable buzz… so much so that with a source like the LPGT and depending on tracks this might get into a sensitive territory for those who are upper mids sensitive. Again, things are smoother with a warmer source. Don’t misread this as the Solo being harsh, it’s not but it sure has much more upper mids presence and bite than most IEMs I know and the overall tone is – with a source like the LGPT – brighter than neutral. Things balance out a bit with a warmer source.
The Solo’s treble is definitely key to its signature, it has very good extension and provides good air and very nice resolution as well as great energy.
Lower treble sounds spot on to me, a perfect balance of exciting energy and smoothness. The Hot Sardines “Come Love (l’amour s’en fout)” intro was pure pleasure out of the LPGT, the piano overtones are just sublime. In Vateani’s “How they call it”, the glockenspiel was as good as I have heard it as well. In Al Kooper and Michael Bloomfield’s “Albert’s shuffle” the electric guitar is again spot on and no signs of harshness although this track has plenty of bite up top. Same goes for the Pixies “Where is my mind”.
The upper treble section is well extended and contributes to the Solo’s very good soundstage and imaging.
The solo is a clear and energetic IEM especially out of a powerful and neutral source like the Lotto PAW Gold Touch. It responds very well to EQ and in my opinion will shine with warmer sources. Given its price range, and the probable match with lower to mid tier DAPs, that tend to be a bit warmer than neutral with a bass boost.
If you’re looking for a clear, energetic, open sounding IEM with strong technical foundations and a touch brighter than reference tuning then the Solo will provide fantastic value for money. If you own a warm DAP or source or are willing to EQ you can shift its signature easily into a slightly warm and fuller sounding reference IEM without loosing its clarity and energy.
I spent approximately 40hours with the Solo, listening on Lotoo PAW Gold Touch and AAW Capri lightning DAC cable out of the iPhone XS Max.
Thanks to Alexandra at Meze Audio for providing a review unit of the Solo. As usual, this review is my honest opinion. No incentive was given for a favorable review.
- 1.3m MMCX braided cables made of silver plated copper custom wires ending in high quality 3.5mm
- Hard Case: protective EVA case with Meze Audio metal logo
- 3 pairs of soft silicone eartips S, M, L
- 3 double flanged eartips S, M, L
- 2 deep insertion double flanged eartips M, L
- Driver: 9.2mm UPM dynamic driver
- Diaphragm thickness: 9µm
- Impedance: 16 Ohm
- SPL: 105±3dB at 1mW/1kHz
- Frequency response: 18Hz – 22kHz
- Distortion: <1% at 1mW/1kHz
- Stock cables: MMCX connector ending in 3.5mm
- Warranty period: 2 years