I'm listening to these earphones right now and they are rather smooth. Considering what I paid for them (like 20 bucks) I would put them against 100-200 dollar IEMs I've heard. I got them cheap cuz I got them in a bundle but stand alone they'll run you around $60 and I think they're well worth that price if you're looking for some
I haven't listened to them much to be honest but they're very smooth. If I had to really critique, they're a bit dark with vocals and you'll likely hear that right away. But they're very listenable at low volumes. I wish I could measure the FR of them, but with all IEMs you can't really expect flat FR from my experience. All IEMs i've ever tried have had their quirks and have never impressed me relative to price point like these have. I would be lying if I said they've got a neutral sonic signature but it's a very listenable headphone. Treble could be a bit louder but I'd rather have a rolled off treble than a rolled-up treble which is common in some IEMs I've heard.
If you're interested in some "listenable" IEMs in that $50-60 range that will have better overall SQ than the norm (IE what you'll likely be pushed at the apple store) these are a nice choice. For critical listening they're probably too dark but if you just want something to put on your ears that looks nice and doesn't sound like total garbage these are rather seducing. They can extract very low level information (which also means they'll be prone to hiss with lesser electronics) while getting louder than one would ever need cleanly. Don't expect active noise cancelation though. Look elsewhere if that is necessary.
The S.Flo I've got driving them has an extremely low noise floor and tons of dynamic headroom and voltage capability on its headphone amp and line-out as well. I haven't hooked it up to the Audio Technicas but I definitely think this sounds as good as any non-battery powered electronic I've heard (and a huge upgrade from the compressed sound of my Sony Walkman F36. Plus it plays FLAC
