Fresh of the chi-fi oem assembly line: (Fengru)
Rosa (D3). $25 USD on Aliexpress.
This is marketed as 1DD 10mm Beryllium Plated Crystal Composite film IEM.
Fit/isolation and build (except massive seams) are not bad. I've been using them with YY 16 SPC cable + CP145 tips.
Bright-leaning V sound signature, with highlight here being clean treble extension. High notes are well audible without sounding piercing or harsh. Very fun to listen to brass instruments.
Low end is above average with powerful and clean bass slam and decent sub-bass extension. However bass is not very well texturized and with complex low end tracks that have multiple simultaneous different basslines (like german techno), there's no good separation and things gets mashed together.
Mids are disappointing. Bass bleeds and there's a drop off in low mids to make the bass slam more pronounced. Male vocals sound distant and not musical. Femals vocals and upper mids are comparatively better due to good treble extension.
Soundstage is narrow and shallow but is tall and extends well vertically. Timbre and musically are below average. Minute details and instrument separation are OK. Stereo imaging is good.
Suggested for those fiending for affordable clean treble, it's very impressive at this price. Bass heads would appreciate simple yet strong bass slam. (My pick for best chi-fi IEM in this price range still goes to BL-03.)
(thanks to
@baskingshark for flagging these)