Binary Acoustics EP321 MEMS

Neither is boosted. The Binary Acoustics EP321 MEMS pairs a 10 mm dynamic driver with a passive radiator, and the bass it makes is tight and natural in level, not physical. Sub-bass (the rumble you feel) and mid-bass (the kick-drum thump) are both present and quick, but this is a lean set.

Natural in position, lean in tone. Voices on the Binary Acoustics EP321 MEMS are clear and sit level with the band, with plenty of air around them from that open top end. What they don't have is warmth or thickness.

Sparkly, openly so. The top end of the Binary Acoustics EP321 MEMS comes from a MEMS tweeter, a silicon chip that moves air directly with no coil and no film, and it is fast. The treble is bright, airy and extends further than anything else I stock near this price. If bright treble tires your ears, pick something else.

For treble-sensitive ears, yes, and I'd rather say that here than have you find out at home. The Binary Acoustics EP321 MEMS is lean and energetic, not warm, and the brightness is always there. If you enjoy that kind of sound you'll be fine, because the ergonomic shell has a pressure-balance vent and it's easy to wear for full evenings.

Wide and airy. All that treble extension gives the Binary Acoustics EP321 MEMS a lot of space between instruments, and the lean bass keeps the stage clear instead of filling it with warmth. It suits classical, acoustic and well-recorded electronic music.

The Binary Acoustics EP321 MEMS has an ergonomic shell with a pressure-balance vent, and it's easy to wear for full evenings. With a 10 mm dynamic driver, a passive radiator, three balanced armatures and the MEMS tweeter inside, I'd call it a medium shell and not a small one. For smaller ears, start with the smallest tips, or try it in Utrecht first.