These are great sounding and great looking headphones, and the quality to price ratio is wonderful. I have not seen/heard anything as nice as these headphones under $50. I love that the cord is removable and can be placed on either side. I replaced the stock cord with one that has controls for volume and that was super easy and inexpensive. My one complaint would have to be the headband. It needs to have about 3-4 more clicks of expandability to fit a larger head or if you are wearing a hat. I have a shaved head and with the headphones expanded fully I can just barely get it to fit on my ears. The grippy rubber on the headband is also uncomfortable on my scalp, and I'd imaging would pull on hair if I had any. I'm going to see if I can get some thin cloth to wrap over the rubber. I'd love to see Koss come up with a retrofit way to replace the top of the strap, and make it a little more adjustable and comfortable.
Review by headphony /
(Posted on 12/17/2018)
Sound is great for the price! Lost a star for the headband.
Overall
Bottom Line:
Overall, I like 'em. Needed a little modification for comfort, but they sound really good for the price. A little bass-y, but otherwise balanced and clear.
Mods I required:
New headband with better padding.
New aux cable with 90° jack.
Pros:
Price (I got mine on sale for $30)
Comfort (ear pieces don't pinch when wearing glasses and fully, though barely, cover my ears)
Cons:
Price (when not on sale; comfort is why)
Comfort (headband hurts after a while. Noticeable pressure on the head.)
Size (big heads need not apply -- I have a moderate size of a head (I'm a dude) and I have these extended all the way.)
Sound
I've used these about a week now, several hours a day (work), and here's my opinion.
They're a bit bass-y. Not excessively, not like my Porta-Pros and certainly not like Dre Beats, but still prevalent. Bass has good control, though, except for the absolute lowest frequencies where separation could be better.
Mids are good, though they can get muddied by very low bass sometimes. Fairly clear otherwise.
Treble seems good. Again, fairly clear. Probably rolled off at the top, but that's common and these don't seem to cut out too much of the top frequencies.
Comfort:
Ear pads are comfy (and replacements are available and cheap if they don't last too long). Headband is another story. It's better than nothing I guess, but it's thin and firm. Not at all comfortable and actually puts pressure on the top of my head which, after a long listening session (which is daily for me), begins to hurt.
Changes I Made:
I purchased a snap-on replacement headband pad from Geekria (for Sennheisers) to put over the existing one and it seems to be working well.
The headphones just BARELY fit my head/covers my ears now, but that should improve as the new pad wears in.
I also changed the aux cord cause I didn't want a mic and I wanted a longer cable. I got a 5ft straight-to-90° aux cord and might replace it with a 90°-to-90° one soon.
While I like that I can plug into either ear and can share with the free ear, the fact remains that a straight fitting gets caught on my shirt collar. (No, I don't have 80s style shirt collars or a really short neck.) I swapped with the 90° end and that fixed that. Good thing cables are cheap. Because I had to swap ends, the cable ends will have bends in them and will likely not last as long.
Summary:
Overall, not as bass-y as my Porta-Pros, which I think is a good thing, but there is still a little more bass than I want. My biggest complaint is the "hard pad" headband. But after some "mods", it's pretty nice.
Final thoughts:
KOSS, add some real padding to the headband, make them extend just a little further for bigger heads, and relocate the input jacks to some position (or some angle) more practical, and I think the $50 tag will be justified.
Review by Picky Eater /
(Posted on 12/14/2018)
Great!
Overall
These are my all time favorite headphones! They're light, comfortable and provide great sound, particularly when paired with a DAC. I particularly like the fact the sound it produces sounds... well... natural.
Review by vsolanoy /
(Posted on 5/18/2018)
vs ur20
Overall
This head phone are great. i came from a used ur20 because i got them cheap on amazon. I almost bought them again for $30. However i ordered these on cyber monder got $20 off. I SOOO HAPPYY!!. i bought $20 skullcandy earplugs but they last only 1 month( bought 4 of them). A waste of money. Just buy these. I really Recomend it. No waste of money in theses. for $50 thats a deal .
Review by Sweetheart /
(Posted on 12/2/2017)
Great headset for a beginner audiophile
Overall
This headset was my first foray into "higher quality" headphones. Before this it was pretty much all built-in speakers or earbuds. I wanted to take my listening experience to the next level though and happened to hear about KOSS through the subreddit /r/buyitforlife who recommended this company for the lifetime warranty.
I just got my headset this morning and I already feel that I have been opened to a new world of audio possibilities. Everything from my favourite songs to random internet videos all of a sudden has new depths. I realize now that a lot of my cheap headsets sacrificed quality by just making everything loud. Wearing these headsets, I hear a ton of sounds I never recognized before.
Reading reviews on other websites, this is still a more mid-range headset in terms of audio quality, but absolutely stellar for the price.
My only con so far is that the headband is a bit hard and it's difficult to wear the headset comfortably at first. I'm considering buying a snap on headband pad to make it a little more comfortable for long-term listening.
I also want to add that the shipping service was great. They advised that the headset would likely be shipped within 3 days of purchase and that it would arrive within 4-6 business days of when it was initially shipped. They shipped it the morning after I ordered and it came in no less than 4 business days. As well their customer service team was very helpful with all my questions. All around very satisfying experience with the company and the product.
Review by Ina /
(Posted on 6/29/2017)
Great sound
Overall
Best bang for your buck!
Review by Mc /
(Posted on 1/25/2017)
Great value in closed-back 'phones
Overall
These are great sounding headphones for the money. I needed a pair of closed-back cans for travel--for general music listening, these are far superior to the $100 studio phones I've had(Audio Technica at-m40x/50x, Sony mdr-7506)and actually give the NAD Viso hp50 a run for their money at 1/4 the cost. Bass is a bit pronounced but has good definition, high's are a bit rolled off but fairly quick and detailed, and the mids(where most of the music is) are excellent. Great job Koss!
Review by Duffy /
(Posted on 1/9/2017)
Best Sound Good Bass , UR423i
Overall
I'm writing from TAHITI, i test this headphone, It's very good sound, bass up, treble and mdle excellent.. If you like the PORTA PRO models , you like this one ....
Review by ARNAUD /
(Posted on 11/19/2016)
Best $49 in audo.
Overall
I've owned Grado 1000Si headphones at $995. I've owned the Grado Sr325i's at $295. I now own a pair of OPPO Digital PM-3 planar magnetics at $399 per set. Astounding headphones, all. I also have been buying Koss Portapros for my hi-res FiiO X5, which sound great. There's your reference. I will say for $49 these new Koss UR42i headphones, I believe, will knock off the Portapros and start a new tradition. My first audition was Diana Krall, early trio work with piano, guitar, and bass, and vocals. for $49 you're getting 80% of the OPPO Digitals for 12% of the price. Well made, fantastic sound quality, and replaceable cable, which is the first and usually only thing to go on beater headphones. Run, don't walk, and get a set of these.
Review by AudioJazzguy /
(Posted on 10/30/2016)
Excellent performer hits way out of price league
Overall
These closed back, circumaural headphones are an upgrade to the UR22, rather than a continuation of the semi-open style of the original UR40. Soundwise, these share a similar profile to the LX elements (Pro 4S, SP330 etc), leaning more toward smooth roll off of the SP330 rather than the signature dual band (low and mid) signature that the 4S features. More fundamentally, they have added what appear to be 3 vent slots to the top of the enclosure that cleans out the lower bass bloat that was a bit too prevalent on the LX circumaurals.
The dual hinge headband is a nice inclusion. Not only does it allow folding flat for storage, but it keeps the microphonics from the rigid headband to a minimum (headband creak was a serious drawback on the UR22). The one major criticism I have is that the headband lacks any padding on the top section like on the similar SP330s - this makes the cans a bit uncomfortable for longer sessions if you have a larger head like my own; smaller headed folks should be fine as the headset is designed to rest primarily via the horizontal clamping force.
Finally, I cannot emphasize how much I love to see a detachable cable on a sub $100 pair of headphones. Bravo Koss! The fact that they use standard 3.5mm connections on either end means one can take this single touch mic cord and use it on any of the Pro DJ, Pro 4S, SP330/540 etc.
Review by Ian /
(Posted on 10/29/2016)
20-20,000 Hz 
35 Ohms 
100 dB SPL 
4 foot 
Limited Lifetime Warranty 
John C. Koss, Founder