Just arrived today, been burning in for about four hours.
Product is CoreCool V2. I'm not particularly well-versed with IEM's, so this is a total layman's review.
The case is about the size of a paperback bestseller with about 200 pages. Inside is a paper flap with cutouts for presentation, foam with cutouts to securely hold the two heads and another cutout for the two cables, one with in-line mic, one without. There's also a small manual but it's all in simplified Chinese and doesn't contain much useful information. The cables are coated with a rubber or plastic of some kind but seem quite durable. The heads are about 2 cm long and aren't perfectly assembled, but it seems like they'll hold together pretty well. The heads came installed with medium-sized translucent white rubber tips, and there were no other tips in the case, but there was another small box with seven sets of tips - small, medium, and large black rubber, small and medium black foam, and two sets of straight black rubber tips that seem designed to cover the drivers without adding much size. These seem to have been thrown in by the seller, though, who also added a ten-sheet pack of corecool branded electronic wipes because Taobao merchants are weird like that.
There are no polarity markings on the cables, so I just plugged the heads in randomly; the first attempt led to a very poor connection with the left side while the right channel was fine, but switching the cable around fixed the problem. At first, the cord-bump sound (microphonics?) was pretty noticeable, but after a couple hours it's mostly gone - maybe because the cable needed to work out some kinks. The sound already seems better after four hours of burn in than when I first plugged them in and listened for a couple minutes. Beyond that, I won't even try to give a sound quality score; I don't have enough relevant experience. I'm not blown away (but then I'm listening to 128mpbs WMVs on a $40 mp3 player), but the sound is much better than what I was using before and I'm satisfied with them for $50.
Now to see if they'll stand up to the inevitable cat attack the first time I forget to store them properly.
of course it's not my money...
