Pros: Treble detail, general clarity, good soundstaging, bass texture
Cons: Lacking in accessories, minor issues with finishing
I purchased my Mentors in the first half of September 2014, and actually received them by the end of the same month. In all, it took only 2 weeks from the day my impressions were shipped to the day they arrived in my hands. I didn't pay for a rush order, so someone at UM must like me a lot. Thanks, anyway!
The general build quality of the Mentor is decent. These are my first custom IEMs, so I wasn't sure what I was expecting, and what bars are set for fit and finish.
I ordered my Mentors in Turquoise Blue, and they came back looking exactly as how I envisioned in the "Custom IEM designer" tool. I actually requested to have the letters "UM" printed in black. However, they were printed in silver instead. Nevertheless, they looked pretty good in tandem with the stock silver cable, so I thought nothing of this oversight.
There are minor bubbles in the shell, but nothing too awful as to warrant a replacement.
The fit was perfect. The Mentors never broke seal in general daily activity (normal opening/closing of month, yawning, lip syncing.. yeah, I do that). Consequently, isolation is excellent, and a good insertion helped nullify a lot of background noise.
Comfort is also top notch, and I believe this is true for CIEMs with a good to excellent fit. I can wear these for an hour and a half (my longest run), and not feel any discomfort. This cannot be said of my universal IEMs, which tend to cause soreness in my ears within the hour.
All I received in the box (apart from the IEMs, of course) were -
1) A round ash tray case, similar to the ones shipped with the JH Roxanne universals. Try squeezing your Mentors in there. Yeah, they'll fit, but only just. And no, only with the stock cables. If your replacement cables are any thicker, they won't fit.
2) A cleaning tool. Par for the course, I suppose.
3) A frequency chart.
4) A warranty card.
You would have thought that the Mentors would deserve a grander spread of accessories. Other CIEM manufacturers are shipping their flagships in Otterbox/Pelican-styled cases, so why did I get an ice puck with my Mentors?
It's the default Westone Epic-esque cable. Nothing special about them. They are sufficiently thick and aren't prone to microphonics. They are also quite tangle-free.
In short, the sound of the Mentors are heavenly. Coming from the Mentors, my next best IEM was a Westone 3, so the jump in quality was very apparent. Nevertheless, I have since auditioned a wider variety of excellent IEMs, but the Mentors still hold weight in this competitive arena.
The bass of the Mentors are well extended, with decent sub-bass rumble. Mid-bass quantity was a little lacking, when compared with bassier IEMs, but they will be present when the track calls for it. Beats were punchy and had quick decay. I listen to a lot of dance music, and genres such as Hard Trance and Eurodance sound fantastic on the Mentors.
Overall, the bass presentation of the Mentors is addictive with decent slam, and should satisfy most, with the exception of the extreme bassheads. If there is one aspect of the Mentors that I would change, it would be the amount of mid-bass quantity. A decent boost would lend the Mentors some further bass authority.
The midrange is lush and full-bodied, and are neither forward nor recessed, relative to the bass and treble. Vocals sound fantastic on them. I very much love the way female voices are reproduced - they take a hold on you, and leave you wanting more.
Instruments such as the guitar are also wonderfully presented, and classic rock (e.g. Scorpions, Gun N Roses, Bruce Springsteen), with a plethora of musical equipment used, sound absolutely wonderful. Everything was cohesive and involving.
This is the part of the Mentor's FR range that sounded most impressive to me. Treble was well extended and presented as clear, sparkling highs that were equal parts smooth and controlled. I am quite sensitive to sibilance, so I must add the Mentor's highs steered clear of anything remotely harsh.
I never felt any treble fatigue, which I normally did on my Westone 3, which tended to sound very sibilant with the wrong tips, or the wrong seal.
The soundstage on the Mentor is decently wide and has good depth. Imaging on this stage is excellent, and I could pick out voices and instruments with ease.
I love the Mentors for its generally great sound. They are musical and fun enough to be used with all of my genres of music, which consists of at least 60-70% dance music. A slightly greater mid-bass presence would be preferred, but this can be easily obtained through the use of an EQ or with a bass boost amp.
I listen to my Mentors with the following sources -
1) iPod Classic 7G (160 GB) with an iBasso D6
2) iBasso DX50 with a iBasso D-Zero or a Fiio E11