ø7.8mm Dynamic Driver


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.

NOTE: This model was most likely discontinued. It is very difficult to find for purchase.


  • A brilliant sound quality. The bass is massive (as long as you have a perfect seal), the mids are loud and clear and the highs are gentle and pleasant.
  • Excellent volume levels even without amplification.
  • An excellent build quality and design.


  • The vocals get pushed back into the background quite often.
  • There might seem to be something a bit awkward about the vocals, and that might have something to do with the slight channel disbalance on the highs.
  • The lack of accessories is quite disappointing.

Package & Accessories


Corrugated fiberboard

Ear Tips - Single-Flange:

M, grey (translucent), ø4mm red bores

S+L, black (translucent), ø4mm bores

Build & Materials


Metal, ø5mm nozzles (ø2mm openings), soft strain reliefs


TPE, soft strain relief


Rubber, 121cm, soft, mildly bent


TPE, 90° angled, long, soft strain relief

Comfort & Fit

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.

Frequency Response

ATE C56R DT5 ED2 ED3 Youth Version ED4 ED9 ED10 ED11 ED16 EDR2 ES3 GR HDS1 HDS2 HDS3 IE80