ø8.7mm Dynamic Driver


The new VJJB flagship - the K4/K4S - which take the brand to a more mainstream direction when it comes to sound. These earphones are near perfection when it comes to sound quality, especially if you appreciate fat, beefy bass with throbbing sub-bass. Perfect for bass-heavy electronic music, but not limited to it. It actually sounds amazing with other genres as well.

The build quality and use of materials is amazing, as usual with VJJB products.

Buy on


  • Simply amazing sound quality. The bass is unbelievable, the mids are precise and crisp and the highs are vivid and comfortably bright.
  • Insanely loud without requiring any amplification.
  • A superb design and use of materials.
  • A great package, good looking carrying pouch and a decent variety of ear tips.


  • The sub-bass can overwhelm the mids sometimes.
  • It was difficult to keep a good seal with them, but your mileage may vary.

Package & Accessories


Hard paperboard

Ear Tips - Single-Flange:

S+M+L, grey (translucent), ø4.5mm bores

S+M+L, grey (translucent), ø3mm bores

Ear Tips - Foam:

Memory foam, black, ø6mm bores


Velour, grey, branded


Hook and loop fastener, generic

Build & Materials


Metal + wood*, ø5mm nozzles (ø4mm openings), rigid strain reliefs


Plastic (matte), single-button




Metal, soft strain relief


Silicone (smooth), 124cm, soft, bent


Metal, straight, short, soft strain relief

  • From a close inspection, it looks like wood covered with thick transparent plastic or even glass.

Comfort & Fit

I had troubles keeping a good seal for a long time with the included tips. The best tips seemed to be the pre-applied foam tips.

Lows / Bass

Massive bass response, as long as you have a perfect seal. The sub-bass is very deep, you can actually feel it very well inside the ear canals. There's a lot of energy and excitement in the sound thanks to the thumping bass.

Mids / Vocals

Warm, surrounding, energetic and very loud. Mostly bright but could seem slightly darkened, especially on female vocals. Not superbly detailed but still quite excellent.

Highs / Treble

The highs are loud and crisp, sometimes may be slightly piercing. They are very bright, but on the detail level - there isn't too much microdetail involved, just the usual highs you can hear mainly on V-shaped earphones.

Frequency Response

N1 V1/V1S