The next KZ earphones to be tested are the beautiful RX. These are quite the eye candy when it comes to design, especially the unique blue cable. But not only that. These earphones seem to be one of KZ's best earphones. The bass is warm, not too deep, and not too overwhelming. The mids are quite precise, even if pushed back slightly, and the highs are crisp and loud, but not as bright as I would like them to be.
The pre-applied tips are OK, but too soft and not grippy. I couldn't keep them in my ears without them sliding out on their own. ROCK Zircon's tips worked like a charm, I got a perfect seal and could hear the true nature of these earphones.
Lows / Bass
The bass is quite deep, precise and controlled, but doesn't go too deep on the sub-bass range, unless you have some EQ involved. Still, the fact that it doesn't get distorted on higher volumes, and that it's so punchy and precise is more than enough.
Mids / Vocals
The mids are clear, loud and tonally precise. However, they tend to get pushed back to the background when there's a lot of bass content in the musical piece. Especially noticeable in neo-folk, where many acoustic instruments are involved.
Highs / Treble
The highs are sharp and quite enjoyable. Not sibilant. However, they aren't perfect either, since they slightly lack brightness and detail.