Disclaimer: This earpiece is provided to me by Earphones Trn for a review.
Setup used: PC > Topping E30 > ST2
The bass was a "wow" factor right out of the box, it came with a good punch, something I appreciate over the roaring boomy bass. The good decay of the bass prevented bleeding into the lower mids, making the bass sound really clean. The amount of bass lies in a sweet spot, giving enough energy to build up the set without stealing the spotlight from other spectrums.
The mids can be broken down into the good and the bad part. Overall the mids have good clarity and the articulation presentation is really nice. The lower spectrum of the mid dominated by male vocals is comfortable sounding, coupled with the clean bass makes a really good pairing. However, things for the upper mid is a different story, the female vocals are overemphasised, making this region sound sibilant and harsh, leading to fatigue. The emphasis on the upper mid can be problematic in the duet set and acoustic pieces, causing male vocals to sound thin and the female vocals overly peaky and an acoustic set where the bass is slightly lacking would not be sufficient to "neutralise" the sound.
Moving on to the highs, it has a pretty good extension, providing micro-details and opening up the stage. This portion is where I would call it a "double-edged sword", the good side is the virtual atmosphere created, allowing really good separation and imaging. But, that also means that the problematic, overly-emphasised upper mids is highlighted and the overall mix just gets thinner.
I replaced the SPC cable with a pure copper one and the issue of the upper mid is partially resolved, suppressing the peaks between the 2k-4k region. It is now much more comfortable to listen to for a longer period of time without getting fatigued, the set also shifted towards being more balanced along the whole mid spectrum with more emphasis on the female vocals. As of this point, this is no longer a big issue for me as I have better tolerance over "harshness" than many. Out of curiosity, I decided to try out the ostry os200 ear tips and "Oh my!", with another round of suppressing the upper mids, it became really good! I did not notice any significant degradation of the audio quality after changing the tips. I would strongly recommend trying this mod if you have the tips!
Why I gave the score
I gave it only a 3.5 for this set simply because the over-emphasis is really rather problematic in many situations and genres of music, some discussed above. If the upper mid was tuned down by ~-3dB, I would no doubt give it a 4.0 for its technical performance and potential.