The Ikko OH10 is a $199 one-dynamic-plus-one-BA hybrid in a solid copper shell, and the parts everyone agrees on are the low end and the hardware. Both measurement rigs show the same thing below 5 kHz: a sub-bass-led shelf of about +10 dB over 500 Hz that slopes steadily down through the mid-bass rather than humping in the middle, a floor between 500 Hz and 1 kHz, and an unusually wide ear-gain plateau that holds +10 to +11.5 dB from 2.6 kHz right out to 4 kHz. Sources match that: deep, fast, physical bass that does not bleed; strong resolution for the money, granted even by the reviewer who rated it 3/5; good imaging and separation; and a shell that reads far above its price, let down by a thin stock cable almost everyone complains about. What divides opinion is everything shaped by fit. The treble splits three ways — smooth and non-fatiguing, hot and sibilant, or actually short on extension — and the two rigs, which agree almost exactly below 5 kHz, diverge by up to 6.5 dB above it, with one owner documenting that the peak itself slides between roughly 7.25 and 8.75 kHz depending on how deep the earpiece sits. The nozzle is short (6 mm) and narrow on a 16 g body, so how deep it sits varies more than usual, which is also why comfort and isolation split: about two-thirds find the ergonomic shape cancels the weight entirely and one third find it too heavy or unable to stay sealed. The midrange divides the same way in the other direction — recessed, thin and cold to one camp, natural and free of veil to the other — and the tonality argument is really one argument about whether a deep V is the appeal or the flaw.
About this product
The OH10 “Obsidian”, launched in 2019: one 10 mm titanium-coated polymer-composite dynamic driver plus one Knowles 33518 balanced armature, in a solid pure-copper shell — titanium coating outside, platinum plating in the chamber, a resin skin over both — at 16.2 g per earpiece. 18 ohms, 106 dB/mW, 0.78 mm 2-pin, and a short 6 mm nozzle. Not the OH1 “Meteor”, which uses the same two drivers in a much lighter alloy shell; not the smaller OH1S “Gems”; and not the 2023 successor, the OH10S “Sapphire Mirage”, which pairs a revised dual-magnet dynamic driver with the same Knowles BA in a glass-and-PVD housing.
In 2019 Ikko took the drivers from its well-liked OH1 Meteor, poured them into a shell machined from solid copper, and charged $199 for it. The OH10 “Obsidian” weighs 16 grams an earpiece — nearly three times its predecessor — and looks like a chip of volcanic glass. It became one of the most recommended hybrids of its era and has never quite gone away.
It also became one of the most argued-about. The same set is described as smooth and non-fatiguing and as sibilant enough to be unlistenable; as having no midrange and as having an unusually transparent one; as the most comfortable IEM a reviewer owns and as one that falls out of his ears. Unusually, the measurements do not settle any of that — but they do explain where it comes from.
