I have been using these earphones for a few months now, and I can honestly say that I am very impressed. I really did not expect a pair of $12 earbuds to sound that much better than the $6 earbuds that I've been using before.

Objective sound quality

My stationary headphones are Audio-Technica ATH-M50x, which are considered one of the best (some swear that they are) cans $200 can buy, and obviously KZ ATE don't sound quite as good, but it is not a fair comparison. I really love the sound, and they sound far superior to any other pair of sub-$25 earphones you get in retail.

They are loud, and so far are free of distortion. They have soft and slightly warm mids that sound quite natural. The high's have a good range, and don't get in your face as long as you are reasonable with equalizer. They do take well to heavy equalization, which is a good indicator.

I expected bass to be a bit more distinct; but with the bass booster EQ they get better. Important to note, that mids do not distort with a strong bass/sub eq bump.

These headphones are very analytical, and have an adequate sound reproduction for electronic / instrumental music, less busy music with simple vocals, and classical tunes. Because of the closed-type earbud (that inserts into the ear canal, vs. covering it entirely), the sound appears concentrated, rather than giving an impression of “being there”, which is understandable for the price.

Build quality