Headroom S2

Evidently, by looking at the frequency response graphs and by simply listening, it would be accurate to say that S2 share the same drivers with S5, but with a slight tuning difference in the mids. The whole sound is pretty much identical to S5 - dark sound with bloated mid-bass. The only difference is that S2 are not as nasal, thanks to not having that bump between 200Hz to 2kHz. Still, the sound is nothing exciting and you can find many excellent alternatives for the same price tag.

Those aren't ergonomic earphones, but I had absolutely no comfort issues with the pre-applied tips. Those tips are simple and look generic, but they do their job perfectly. These earphones are quite smaller than both M8 and S5, which makes them even more comfortable.

A lack of sub-bass along with bloated mid-bass and upper-bass/lower-mids darkens the sound and creates a certain distortion, as if the recordings were made in an echo chamber - loud but unclear, with a muddy echo effect.

The worst aspect of these earphones is the mids. Vocals and instuments sound distorted, but unlike S5, they are not as nasal. They maintain the same color - dark and unnatural. These mids are more listenable than S5's mids, but still quite weak when it comes to clarity.

The highs are just nice, not exaggerated, but quite crisp. Definitely not the most transparent treble out there, but more tonally accurate than S5 and a bit more detailed as well.