Review – Koss KDE250

Compared to, say, 15 years ago, there aren’t many quality flagship earbuds in the headphones market today1. Gone are the heydays of Sony’s E888 and Audio-Technica’s lovely ATH-CM7. In its stead, the in-ear monitors (IEMs) have taken over. A brief glance at the online Sony Store shows just one lineup of earbuds, and they cost $10. The rest: IEMs, prices ranging from $10 to $500. A similar situation exists on Audio-Technica’s own store. ATH-CM7 has no heir2: the only open earbuds are ATH-C505i series and ATH-C101, topping out at around $20. For IEMs, though, the sky is the limit, with ATH-E70 costing a hefty $400.

There have been some sporadic attempts at producing flagship earbud products. Yuin’s PK-series earbuds were as spectacular-sounding as they were plain-looking, with prices to match (PK1 was around $150 if memory serves). Sennheiser released MX985 in 2013 to muted response. Bang & Olufsen updated their enduring over-ear design of A8 for smartphones with the Earset 3i, and there was also the Aurvana Air from Creative.

So it’s a cause for happy surprise when a known manufacturer comes out with premium-priced new earbuds with a very unique, bespoke design. It’s an even bigger surprise when that manufacturer happens to be Koss, perhaps the king of budget headphones with enviable quality-to-cost ratio3. At retail price of $250, the Koss KDE250 is not just the most expensive non full-sized headphones from Koss, but also their second most expensive product ever4.


KDE250 has an over-ear clip-on design that is, unlike B&O’s A8, unashamedly functional. The metallic clip looks like the screw driver you get from IKEA packages and doesn’t extend all the way over and around, instead nesting on top of the trough behind the top of the ear. The clip is detachable and has two other sets of varying lengths included in the box for added customization. There are scroll wheels on each body to control the height of the clips’ extension. Among the most interesting features is how the headphone unit is positioned: placed at a 90 degree angle to the inner surface of the earbud body, the headphone unit doesn’t so much fit into our ears as placed strategically to project the sound towards the ear canal.

The placement of the units is a very unusual design choice that brings with it clear advantages and disadvantages. There’s the idea that oblique positioning of the sound units yields increased soundstage, one previous example being Sony’s MDR-MA900. KDE250 takes this to the extremes, and whatever the physiological magic is, the sense of scale to the music on these earbuds is pronounced indeed. The drawback is that KDE250 makes no attempt to fit in the ear and so there’s little sound isolation to be had.


Before returning to the issue of fit and design, here’s some thoughts on KDE250’s sound, for which good and bad things can be said with equal conviction. Put simply, KDE250 is very much a product of Koss’s sound signature. What this means is: generous bass, subdued treble, the mids doing what it can in-between. The lows are not overwhelming by any means, but they are unquestionably the dominant element. The mids are inoffensive and can become somewhat appreciable, but the lack of isolation doesn’t help. As a lover of treble-leaning headphones, I wasn’t fond of KDE250’s muffled highs, but this is compensated to a large degree by its impressive soundstage. Its sense of scale is arguable one of the bigger ones that I have come across among earbuds and IEMs and is definitely the key calling card here.

If KDE250 had a more comfortable fit it would really be something that you could put on for extended periods of time and make you forget you’re listening to earbuds. The soundstage is good enough to make me occasionally overlook the muddy treble. But the steel over-ear clips are short and inflexible, so you never really achieve full fixture around your ears. The design of the sound units with the 90-degree positioning calls for minimum disruption to the fit, but sadly that is hard to achieve with the clips as they are, especially on the move which is how I expect the KDE250s to be used by most people.

KDE250 nevertheless leaves a strong impression. Not all positive, but a strong one with very clear strenghs, and some weaknesses are ripe for correction in a ver. 2 revision. Koss deserves praise for not following the industry trend but instead releasing a product so bold and interesting. The portable headphones market today is one where the manufacturers are engaged in an arms race over IEMs, so it’s heartening to see a major name take a chance on an entirely new earbud design with an equally unique sound.


  1. An exception that proves the rule (or rather completely undermines my opening argument) is the Apple Earpods, released in 2012. Perhaps it’s for another post, but one of the possible reasons why there haven’t been many new earbuds from other companies is that Apple finally decided to bundle good earbuds with their iPhones, something people had cried out for for a decade since the first iPods. And the EarPods are actually rather good indeed, with decent soundstage (perhaps achieved by a design approach quite similar to what Koss has done with KDE250), good resolution and few glaring weaknesses – a bargain at $29. Compared to the Yuin PK1 – a personal gold standard of earbud sound – the EarPods put on a good showing. Since it comes as standard in every iPhone, and is so cheap to buy separately, the EarPods arguably killed any incentive for 3rd party OEMs to try their hands at quality earbuds.
  2. There were, however, CM7-series follow-ups like ATH-CM700.
  3. The most iconic of which is the Porta Pro
  4. In first place by some distance is the ESP950, a $1,000 electrostatic monster.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s