Here are my very belated impressions on NiceHCK YDX
All impressions had throught TempoTec V6 3,5mm, High Gain, Volume between 20 and 23 out of 100 volume steps.
All using Faaeal Full Foams, except by YDX that was using Trig Rain Donut Foams, and A-Bells, which was using Trig Rain Full Foams.
Traceless is the most 'balanced' of the bunch, not being too much exaggerated when compared to its brothers. Its bass quantity sits between YD30 that has very little, and YDX that has more, it has some warmth in it, but in general is clean in the frequencies that cause warmth, having no much emphasis on it. Its treble extension is on pair with YD30, but is brighter than the former. Has a slight peak in 2khz, but nothing too major.
Has the biggest stage of the three, wide, a little tall, not much deep. Separation is pretty similar to YDX, and both lose to YD30 by a little margin; detail retrieval is also close between Traceless and YDX, but this time around, YD30 is worser than them. All the other technicalities are better on Traceless.
Flat-ish bright, big stage, decent technicalities.
YD30 is very lean with some sharpness in 3-5khz, also some minor sibilance; midbass is the cleanest of the three, but it does not go as deep as the other two, and has also the least present bass overall. Treble is in between Traceless emphasized treble, and YDX kind of recessed one. In general it sounds cleaner than YDX and Traceless.
Soundstage is intimate and closed in, it is not big, nor it sounds 'open', has better separation than its brothers, but is behind in everything else.
Midcentric, sharp mids, early bass roll-off, poor technicalities.
YDX, if well fitted, has midbass punch (at least with bassy tracks), and more midbass quantity than the other two, its bass extension reaches deeper than YD30 and Traceless; its mids are foward in the mix, they are warm and 2khz seems to be dipped, also they don't have any sharp peaks (at least to my ears); the highs are not pronounced in any way, maybe even a little recessed, they also roll-off earlier compared to its predecessors.
Its technicalities are either on par, or are inferior to Traceless; comparing its soundstage to Traceless i would describe it as somewhat wide, even less tall and similar depth, so second place.
Midcentric, warm, midbass quantity, bass extension, inoffensive highs.
Putting a 4,4mm cable in YDX makes its bass more tight, it also lowers them a bit, 2khz shows up a little, and treble rises just a tad. That muffled and soft sensation disappears. Technicalities improve a little.
Other Comparisons
Lun Sheng Aeolian Bells
Both are midcentric and warm.
YDX has more warm mids, and sounds more intimate and softer, maybe even a little muffled.
A-Bells are brighter with better treble extension; bass is similar, more present and extended on YDX, but tighter on A-bells.
Aeolian Bells technicalities are better in all aspects, separation, imaging, positioning, soundstage, resolution, you name it.
FAAEAL Iris 2.0
Complete opposites, Iris 2.0 is V shaped while YDX is midcentric and warm.
YDX has much more warm mids this time, and is even softer sounding, while Iris 2.0 are way brighter, has less pronounced mids, is more extended on both side, also has more controlled, more impactful, and maybe even a little more midbass quantity overall.
While its soundstage is not super large, it has decent quantities of all dimensions, and is less closed in than YDX. No further comments about the other technicalities, as all are better than YDX's ones.
In conclusion, i would like to say that YDX remembered me of how fundamental is to have a good fit, if i simply put it in my ear, very little bass, but with very little fiddling around, i could fit it better and get a much better sound as result; different from bigger shells that i usually have to mess around more to fit proprely, i had less difficulty doing so with YDX. It is also actually my most confortable bud.
Its cable is very lightwheight, and has shown minimal to no tangling until now.
If you get it for around 10$ (which was what i paid for it), i think it is decent, if not, i would pass, i do not think it worths any more than that.