***Chopin is available on the market for 200 dollars. I bought the product myself to write an independent review. 70+ hours listened before writing the review.
Specs
-->Impedance: 12Ω@1kHz.
-->Sensitivity: 122dB/Vrms.
-->Effective Frequency Response Range: 5Hz-20kHz.
-->THD+N: <1%@1kHz.
-->Designed in Collaboration With Gizaudio.
-->Four-Driver Hybrid Setup.
-->8mm Ceramic Diaphragm Dynamic Driver.
-->Customized Mid-Range Balanced Armature Driver.
-->Customized Composite Dual Balanced Armature Driver for High-Frequency (2BA).
-->Stunning Design With Stainless Steel Facepanels.
-->3D Printed Resin Material Cavities.
-->High-Purity OFC SIlver-Plated Litz Cable.
-->Available in 3.5mm or 4.4mm Termination Options.
Foreword
A device with good techniques and almost well toned. I say almost because unfortunately some "personal" choices have made this iem good instead of great. For those who like flat sound this headphone is just a fun tool but for those who already like/listen to V-shape it is a very good choice. (its U-shape btw)
Build
It's a horizontal box design and I like that. I prefer that rather than always seeing the same box shape.
Honestly, I don't like the design at all. The fit is not bad, the durability is okay. but the shape is a complete fail. The cable is very average but there's nothing bad about it, in fact I'm glad they're not thick and bulky. The hard case that comes in the box is ordinary plastic but I think it's nice (it's not like you're going to run over it with a tank). The two little bags for the shells are very cute and the quality is excellent but I would have preferred them to be in one piece. The tips? Don't even ask, they're a disaster. Both not enough and wrong. The brush is fine. We'll use it
Sound
Chopin is not a difficult iem to drive. In addition, it does not distort at high power. It gives a clean soundstage with a clean background.
I've always liked V/U-shapes that are not extreme. Somehow iems with this type of sound appeal to everyone and find a place in every inventory. Chopin is a good example. But it has some mistakes, we will talk about them.
Female vocals and treble are a bit bright in general. But for a fish swimming in a sea of chi-fi, there's nothing to annoy. Although I had have to turn the volume down seriously at 04:31-04:42 in the track "Bülent Ersoy - Bir ben bir Allah biliyor". Based on the performance in the same song, we can say that there is good imaging.
Except for those who like flat sound, this iem is versatile. Mid gives a very good technical performance and brings enough instruments to your ears. These instruments give you all the detail behind the female vocal. Despite the tuning, the micro detail reproduction in the mids is admirable.
Bass
The lower frequencies are the best part of this headphone. I really enjoyed all the EDM, hip-hop and pop music I listened to during the test phase. The controlled, textured and deep bass response comes with a good technical skill considering the volume. With very good extension, the sub is a real showstopper. The only point open to critique is the lack of midbass when listening to an orchestra. It's forgivable given the overall low frequency performance.
Mid
Despite the warmth of the overall sound, the mids themselves have a cold timbre, which you can easily hear in songs you've listened to before in genres like rock/jazz/blues. This results in a transparent feel and instruments that sound more resolved than they actually are. There are two reasons for this general impression: Missing low mids and prominent vocals. The lack of low mids gives the sound a little bit of thickness but at the same time some depth. The loudness of the vocals, especially the female vocals, causes some loss of texture in all the instruments, but also a "cold" resolution increase. The other effect of the setting that amplifies the vocals on the instruments is, as expected, the upper violin/guitar tones that become sharper and closer. This resulted in a loss of separation around the vocals. Other than that, the instrument separation is quite enough and successful for the price.
Treble
Treble is average. It's a bit bright and has a standard resolution. Air frequencies are bullied by the lower treble. Cymbals are nice when there are no instruments and vocals, but they damage when the soundstage gets crowded. I would have preferred them to be more quiet but that's purely personal, objectively there's nothing bad about the treble, it's just value for money. The amount of extension is quite well tuned, the placement is a bit poor compared to the rest of the sound. The cymbals may be the most natural part of the whole sound (despite the tone). Female vocals have too much boost at the points where they become high-pitched, which is actually the whole problem. If we solve this (hypothesis) the overall rating of the sound will go up.
Final Words
With its technical skill, with its capabilities at some points and shortcomings at others, the chopin is a device that is worth its price, we can say that it is overall positive,
and the low frequencies are fantastic. If you don't mind a bit of brightness and U-shape sound, you can safely choose it.
yeah youre going to LOVE this. 
