Koss UR40 Headphones Review

A budget open back built from air and good sound

Alex Rowe
9 min readMar 25, 2019

I love the Koss PortaPro. As cheap open headphones go, it’s probably the best one. A small portable retro design meets 60 ohm drivers tuned for a fun sound that balances the casual and professional audio worlds.

And it’s usually less than $40.

It’s the sort of headphone that’s good enough for the money to make you regret later, more expensive headphone purchases.

Some folks prefer the KSC75, an ear-clip headphone built around the same driver platform. It’s even cheaper, often going for around $16.

Until last week, I thought these two models and their various colors and iterations were the main examples of the Koss 60 ohm lineup…but there is another.

In the early 2000’s, when Koss was obsessed with spraying Titanium coatings onto things, the Koss UR40 was born. It’s an over-ear open back headphone with a…funky, cheaply-built design. And inside, a 60 ohm PortaPro driver.

But sprayed with Titanium.

Somehow, that model stayed in production for the last 17 years and now I’m here writing up my thoughts about it in a coffee shop.

OVERVIEW

First launched in 2002 (man, that Koss History page is so excellent), the Koss UR40 normally sells for $40, but you can easily find it for around $25 or so if you shop around. It’s a fully open headphone that provides essentially no isolation, so it’s best suited to quiet and private listening environments.

You can get by in a coffee shop like I am right now, but it’s far from the ideal environment for them, no matter how many claims Koss makes on the box about this being a “best of both worlds” product. It’s open, open, and more open.

The 1.2 meter cable is permanently attached, and comes with a 6.3mm adapter fitted over its 3.5mm plug. You can also fold down the headphones and take them with you, if you want to. The box contains no other extras or documentation, just a fascinating and complicated cardboard insert holding the headphones that’s harder to remove than it appears.

My first impression of the headphone on taking it out of the box was that it was made out of paper, popsickle sticks, and glue. Ew, my brain said, this is a cheap and stupid thing and I shouldn’t have purchased it. I’ve been taken in by Titanium.

On first listen, I immediately gravitated towards its rolled off subbass with a frown, and remembered that I was wearing a mesh piece on top of my head that felt cheaper than my old Little League baseball cap.

But I pressed on.

I’m glad I stuck with it. And if you get one of these, you should too. The shell is borderline stupid, but the innards are vintage Koss brilliance. With added Titanium.

After a couple days of listening, here are my thoughts.

The box has actual product shots on it instead of the CG renders you’ll find on basically every other audio product package.

SOUND QUALITY

Like the PortaPro before it, the UR40 has a warm, generally impressive sound that feels much bigger than its price and its flimsy enclosure both suggest.

It’s not perfect. But it’s about as perfect as you can get for $25.

The subbass region is too laid back for my tastes, but still present enough to extend all the way down to 30Hz or so without you having to crank the volume up. As I sat last night listening to 30Hz test tones, like you do when you’re reviewing a thing, I noticed just a little bit of crackle and distortion on the left channel. That’s not great, but also, you probably won’t be listening to test tones.

Basshead headphones, these are not.

But they still have just a touch of pleasant warmth and oomph to them, just like their PortaPro cousins. The open back design means that only so much “slam” can theoretically exist, and these do a reasonable job of providing a little fun in the midbass region without destroying clarity in the rest of the sound.

Midrange is nice and neutral, and relaxed. There’s no harshness in the upper mids. There’s no mud in the lower mids. It’s just nice and present and good.

Treble is a little bit all over the place, and a little… crinkly. Sometimes it’s great and other times it sounds like it’s being rendered by a cheap piece of plastic wrap. It has a touch of harshness on certain instruments, and a lack of presence on others. It’s laid back enough to not be fatiguing, but sometimes it sounds brash or sibilant when sound hits one of its peaks. This can come across as an artificial detail boost, but in other tracks it just sounds off.

I’m nitpicking honestly. Sound quality is quite nice overall and as accurate as a slightly laid-back signature can provide.

The overall tilt of the headphones is warm, and towards the gentle midbass hump. The rest of the frequency range does a good job of existing and not ruining your day. The sound profile is not unlike that of the Sennheiser 500 series, which has a starting price around 5 times that of these headphones. The Sennheisers are more refined and offer a wider overall soundstage and smoother treble, but that the Koss model gets anywhere near that for this low price is hilarious.

Soundstage is a little thinner than I’d expect from an open back, possibly due to the uneven treble response, but imaging is fine and accurate. I had no trouble enjoying a few hours of Skyrim on these, though sometimes when I opened a chest I scrunched my face at how weirdly crunchy and off that particular sound effect was.

It’s really hard to complain too much about the sound here, especially for the price. It’s very similar to the creamy and decent sound that the PortaPros have, but in a bigger shell. It’s good until you notice one little thing here or there that isn’t, which will snap you back into the reality of their price for just a second. You’ll find that threshold faster if you‘re really into music and critical listening, but most of the time you just get shockingly decent audio.

As far as I can tell, the leatherette pads and the big cup enclosure don’t really do anything to improve or drastically change the sound compared to the smaller models with this same speaker driver. That’s a bummer. I did all sorts of experiments shoving the pads closer to my ears or further away, and taking my glasses off. But the sound was consistent throughout.

Although the drivers are rated at a 60 ohm impedance and the sensitivity is a respectable 98 dB, it’s quite easy to push these to loud levels. You won’t need an amp or any special hardware here.

COMFORT

The insides of the cups on this headphone will almost certainly touch your ears, unless your ears are glued to the sides of your head. If you can deal with something gently resting on your lobes, then everything else here is as comfy as wearing nothing at all.

That’s the advantage of the cheap plastics and materials used here. The headphone is so light it practically doesn’t exist.

Ear pads are made of that terrible cheap leatherette you’ll find on other cheap headphones like the Sennheiser HD201 and 202. It’s a crinkled vinyl that’s basically pretending to be leatherette. It’ll get almost immediately sweat-covered on any parts that touch your skin, but it wipes off just as quickly.

The foam underneath is the cheapest non-memory foam you can imagine. It gets the job done, I guess. It provides no real isolation or bass enhancement, but it does feel a little bit squishy when you touch it.

The mesh fabric serving as both the headband and the headband padding looks like a joke. It just hangs there by some string, and it seems like there’s no possible way it could work. But it does.

Since the headphone weighs nothing, the headband doesn’t have to do a lot of work. The mesh is nice and wide and does a good job of spreading the non-weight of the headphone across your whole head. And it breathes well since it’s only one step away from being nothing at all.

You’ll forget you’re wearing this headphone a few seconds after you put it on. It even fits on my big dumb head with one adjustment click to spare, and on the smallest setting its likely tiny enough to work for kids. Not bad!

DESIGN/BUILD

Koss put a lot of clever design touches into this headphone, and then built it with the cheapest parts they could find.

The first design highlight is the little hinge in the middle of the headband support. This allows the headband to expand and contract, both when it’s on your head and when you collapse the ear cups down for storage. I’ve never seen a hinge placed here before. Yes, it probably makes the whole thing weaker, but this is a $25 headphone, so I’m not expecting the world.

The ear cups have clicking hinges to indicate when they’re folded down or extended, and the adjustment sliders are surprisingly robust as well. I’m used to Sennheiser and Audio-Technica’s cheaper models, with their smooth and mushy actions, so having some clicks for feedback here is nice. Yes, once again these clicky parts are made from plastic, so they’ll wear down over time, but it’s still awesome to have them.

You won’t look silly if you choose to wear these outside, at least, profile-wise. They sit nice and close to the head. Unfortunately, the ear cups are made from a shiny cheap gray plastic that’d be right at home in an electronics store in 2002…because that’s exactly when these were designed.

Everything about the build is sub-par, and you’ll have to remind yourself of the price you paid. The cord is springy and thin. The plastic has an uneven finish to it and feels very hollow. The insides of the ear cups are covered with a basic filter paper instead of a nice foam. That paper also prevents you from seeing the Titanium driver. I wish a transparent mesh was used in the cups, as I think being able to see the driver would win these back some style points.

At least they put a nice picture of the driver on the box.

In spite of their flimsy construction, Koss still offers their trademark lifetime warranty on these. So make sure to register them if you buy them, and you can get easy replacements!

FINAL THOUGHTS

It’s hard to hate on these too much. And that really says it all.

They’re built from nothing, they have a design that’s equal parts fascinating and outdated, and they contain a proven driver platform sprayed with a titanium coating for reasons. If you push them really hard you’ll quickly find their limits in the bass and treble departments, but if you listen to them like a normal human you’ll just get totally good sound that you paid basically nothing for.

These live up to the reputation of the PortaPros, and they’re a great starter open back headphone. Their cheap frame promises nothing, and their sound competes with headphones priced five times as high.

I’d take these ten times out of ten over the Sennheiser HD 201 or 202. But I also think the PortaPro is worth its slight premium over these. That classic headphone has a smaller overall frame with a better build and design, and its clever temple pads mean you’ll get an even softer fit on the head.

If Koss were ever tempted to give this speaker driver an $80 enclosure with nice memory foam pads and a detachable cable, it’d decimate that crowded market segment and leap to the top of my personal recommendations list.

As it is, they’re crushing it as much as a gray thin flimsy plastic budget headphone can.

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Alex Rowe

Commentary about Games, VR, Tech, and Music | Find me on Threads: threads.net/@arowe31