Foobar2000 > Magni 3+ / Modi 3+ - No DSP used - No EQ used
*Note - Price is factored into the score.

Non-auditory observations: Comfort is excellent. Arguably the most comfortable headphone that I have ever used. These headphones are lightweight, but they rely on the base and center of the ear to hold it up: some people might find this uncomfortable. The durability is not good. My experience with them is that they last ~1 year because of damaged wiring. The cable on the KSC75 is stiff and the 3.5mm plug is right-angled, which I find provides more durability. Now, the KSC75X is Drop's version of the KSC75, and they measure around the same minus the bass from 10-100Hz. These cost slightly extra but the cable behaves better and is rubberized. My suggestion would be to get the KSC75X.

Tone: Not too many complaints. Sound is mostly natural with some plasticky notes. Treble focused and extremely subtle sub-bass. Mid-bass and midrange is neutral. Treble sounds forward and splashy in a good way: good treble definition.

Tech: Average soundstage that is limited by its driver size and also wearable form that places the driver on the ears. Good separation because of the lack of present bass in general. Imaging is okay. Treble detail is good. Midrange and bass notes are lacking in some detail because they are less defined and distant.

Song Tests: (VS KSC75X modded with Fibonacci grilles and a 0.5in coin/quarter cutout in the center of the foam)
Evan Call - Back in Business



(0:00 - 0:15): The strings at the left are introduced more distantly while the bass is not strong at all. There is a subtle "tap-dancing beat" that starts at 0:03 and ends at around 0:16 in the song. This part is hard to nail and with the KSC75: they were barely audible and not dynamic enough. With the KSC75X, the strings are introduced more intimately, more natural and better defined. The bass is more present and the "tap-dancing beat" is slightly more audible with more range.
(1:18 - 1:21): This short-stringed part is played with no congestion. The strings are not too well-defined. The KSC75X sounds more warm with a slight amount of congestion from the instruments and the added audible bass.
(1:30 - 1:36): While the separation is good, the piano notes and the main instrument are quite distant.

Ragdollz - Mangekyo



(1:12 - 1:20): Tones are good but it sounds pretty boring. Mids and bass sound flat but the cymbal taps do stand out.
(1:46 - 2:04): Less overall dynamic sound on the KSC75. The constant cymbals do really stand out at 2:00. Less center imaging on the KSC75.
(2:04 - 2:22): The fast kick drums sounds pretty flat and the electric guitar is well separated, but doesn't have a great, full tone.

Hiroyuki Sawano - Blumenkranz



(0:47 - 1:10): Main vocals are distant and the whispers are barely audible. The KSC75X picks up the gasps/air-intakes during the whispers better, but the whispers are also barely audible. Better center imaging on the KSC75X.
(1:38 - 2:00): The drums sound less warm with less real reverb. The cymbal-like sound is nice and splashy. The drums introduced at 1:48 has little authority. But again, the KSC75 has better separation and more soundstage.
(4:00 - 4:18): Nice spacing between instruments but the main blooming instrument is slightly off: not enough haze.

Thoughts
The purpose of me comparing the two nearly-identical headphones is that you could mod and change the sound-profile of the KSC75 if you want: not too drastic, but enough to increase the midrange detail and the note definition. The Fibonacci grilles creates more openings for sound to travel through, theoretically making the sound more intimate and perhaps more detailed. I suspect that the kramer mod does similar things. With the quarter mod, solderdude noted that the drivers sit slightly closer to the ear. It creates less dampening for a more direct and detailed sound. The compromise is that the stage is less, especially the sense of depth. The notes become more congested with the increase of other sound elements. Are the mods worth doing? For what I hear to be a more natural and more defined headphone with less soundstage and more congestion: I think they are. I normally use crossfeed for headphones. Crossfeed + stock KSC75 = an even less dynamic listening experience.

Conclusion
For the price of the headphones, I can not think of anything in its range that could beat it. Overall the tonality is good with the detail and soundstage being the major cons. For what it offers, I think 4/5 stars is a fair rating for these.

KSC75s are the second of the Koss’ most popular headphones. Well they have several and now there is Utility series, sure but KSC75s are still special. You can also read this review at our website https://www.mobileaudiophile.com/koss-ksc75-review/

Disclaimers​

Without boring you too much, I don’t necessarily have a sound preference. I tend to enjoy different sound profiles as long as they do well what they intend to do. I’m not very sensitive to treble so can enjoy most notoriously bright headphones, however I’m somewhat sensitive to upper mids area. Please keep these in mind.

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Built, Comfort, Trivia of KSC75​

KSC75s are kind of a legend in the “audiophile” community. Although they use almost the same driver with the Porta Pros, probably titanium coating on the driver changes the sound, arguably for the better. They come with ear clips instead of a headband. They are also much cheaper; while MSRP of Porta Pros is 50$, KSC75s are sold for 20$, what a bargain! However ear clips are annoying, at least they are for me. They pull down your ear, hurt after a while and seal even less than Porta Pro. Fret not though, ear clips are easily removable and interchangable with Porta Pro headband and several other 3rd party headbands. Also you can use change the ear cushions to suit your taste in color, style and tuning, just like Porta Pros.

Sound of KSC75​

If you are a FR graph guy, imagine tilting the Porta Pro’s FR graph counter clockwise and you get KSC75’s FR. But I’m here to explain what ears hear. KSC75s are as neutral as it gets.


For the bass, these don’t have much of a sub-bass extension either, maybe even less than Porta Pro. In the mid-bass there is a slight hint of a mid-bass hump which adds a little fun factor but nothing excess. It just makes the sound not very lean which is very welcome if you ask me.


Mids are quite good and neutral, not forward, not recessed either. In this sense presentation is very similar to Sennheiser HD600s. In my HD600 review I said they are epitome of neutrality, the dictionary definition of neutral for audiophiles, if you will. Anyway, KSC75s are not as intimate but they don't become shouty either. Porta Pros have more of an intimate presentation in this sense.


If you are sensitive to treble, they may come as too bright or harsh sometimes but they don’t offend me unless I turn the volume too much or the song itself is excessively harsh in that region. They are definitely brighter than HD600s here. If your treble limit is HD600s', then KSC75s might be too harsh for you. Still I enjoy the extra zing. They are pretty detailed and have wider soundstage than average. Again KSC75s are very balanced. Timbre is also very natural, doesn’t sound off in any way.

Conclusion​

KSC75s are the most "audiophile" headphones in Koss' on ear headphones line-up. They produce the most correct sound in the sense of fidelity to the original recording. However music enjoyment is not just about fidelity and if you go higher in price you will come across more technically capable headphones. But for 20$ what can go wrong? You can even play with them a little to satiate your curiosity without breaking the bank. Tonality-wise they can compete with 100$-150$ range. Just don't expect miracles and you will be fine.

Into:
The KSC75 is one of the more popular models made by Koss. They make great value-for-money products in their budget lineups. The KSC75 is no different. It is an open-back clip-on headphone with Koss's titanium coated 60-ohm driver with a neutral sound signature. After using them for more than a month on a daily basis for 7-8 hours a day, I am writing down my review.

Disclaimer: This unit is bought by me and all my opinions are completely honest and unbiased.

Packaging:

The packaging is very minimalistic with the box including the headphones and some paperwork.

Build and Comfort:


The build quality of these headphones is very bad. The wire is very thin and plasticky and it can break very easily. It holds its shape and never straightens up. The plastic used in the headphones feels very cheap. As these are open-back headphones, they let all the noise in due to lack of seal, and they bleed a lot of noise. And sometimes, the hair can get stuck on the pads and can get through the pads to the drivers and can cause buzzing, especially on low frequencies. It can be fixed after removing the pads and giving them a quick blow. Comfort-wise, they are very comfy and the pads are very soft. After a while, you even forget that they are on your ear. They are also very stable due to their clip-on design.

Sound:

This is where these headphones shine. They are very well-tuned and have a neutral sound signature with emphasis on the mids and sub-bass roll-off. They are one of the best sounding headphones at this price point and even competes with headphones way above its price bracket.


(Courtesy: Crinacle)

Bass:
They have a sub-bass roll-off so it doesn't have the rumble that other headphones have at this price range. But the bass is punchy and is enough for most people. But if you are a basshead, you should look for other options.

Mids:
The mids are a bit too forward due to which, the vocals feel a little bit shouty and can cause fatigue after a long time at high volume. Other than that, vocals and instruments sound very natural.

Treble:
Treble is very natural and very detailed without being fatiguing.

Soundstage:
The soundstage is pretty average, not very wide.

Conclusion:
The Koss KSC75 are the best headphones under $100 in terms of sound quality. They even compete with headphones way above their price bracket and even beats a lot of them in terms of sound. They have a neutral sound signature that you will rarely find at this price point. The mids are a little bit forward and shouty, but eq can easily fix them. However, in terms of build quality, they are very cheap feeling and not good and the wire is very thin. If you want a headphone for sound quality under $50-100, The Koss KSC75s are the best headphones at this price point and are the best value for the money. They would be the endgame for most of the people out there.

Disclaimer: This review is based purely on my personal impressions, and won't go too detail as I prefer a more straightforward style preview.
I first heard about the Koss KSC75 when I watched Crinacle's video: THE BEST GAMING HEADPHONES don't matter. My interest peaked up because of the fact that a 'clip on' headphone is somehow really good for gaming for under $50. I looked at various reviews about the KSC75 on Youtube and Reddit, and all of them praise it really well as a very good value headphone. Because of this, I've decided to buy it as my new headphone for gaming, and also for music listening. I bought it from Lazada for RM123 ($29.29) without shipping costs. I still have doubts during this time, and expected it to not 'wow' me as much I expected.

The whole package appeals as a standard, non too appealing box, which is refreshing as most packaging of earphones/headphones on stores/e-shops nowadays always emphasis on 'Strong Bass, Clear Sounds, etc.

What's included:-
1. The box with info regarding Koss, and 'Hearing is Believing' quote.
2. Notes regarding environmental protection, and lifetime warranty.
3. Hard cheap plastic packaging with a cover.
4.The headphone itself.

Specifications based on it's website:-
- 15-25,000 Hz
- 60 ohms
- 101 dB SPL/1mW

Price: $20 (bought it for $29.35)




Appearance & Feel
It's unappealing design does gives out that cheap, lackluster sounding headphone vibes. The cables just emphasis it more as it looks cheap, and feels cheap when I first hold it. The headphone itself is made from hard plastic, but not that cheap feeling kind like those cheap headphones, which surprised me. It's really light, which is expected due to the build materials of this headphone. Finally, the ear pads feels alright, not too thin and not too thick.

Wearing
Since I ever wore a clip on headphone before, wearing the KSC75 is easy for me, so there's no struggle of trying to figure out on how to wear it. Unlike the previous clip on headphone tough, there's a bigger space between the clip and the ear cups, which makes this headphone easier and comfortable to wear. The ear cups itself actually swivel, which makes the comfort more better and also easier to adjust for more comfortable fit.

Sound
Plugging it into my pc, I went to Youtube and start listening to my fav. songs. As soon the song start playing, my mind was blown away and all of my doubts regarding it's sound quality are completely gone. It actually sounds so well that I will think this as an expensive headphone if I were to perform a blind test of guessing the price of a headphone. As I kept on listening to more songs, the amazement just gets more better and better. It's definitely great and way more better than I expected for it's price and appearance. Also, no amps needed as it runs pretty easy.





Comfort
It is and still very comfortable for me, but it might be the opposite for some people due to ear sizes and shapes. The good news is that the clips are bendable which helps to improve the comfort and fit of the headphone. The design of the clips and the fact that the ear cups swivel made the headphone fit just right on my ears instead of pushing it, which is why I'm able to wear it for +3 hours and still feel comfortable, just with slight pain around the outer ears where the clips rests.

Sound
Still the same as my first impression of the sound. Really great and enjoyable overall with some downsides which I'll explain below later.
When I listened with the KSC75, I noticed that it has:-

1. A 'neutral with rolled off bass' sound.
- Neutral as like the sounds in general are clear and detailed, not harsh and not muddy. Bass is decent for me, but those D E E P rumbles just rolls off, hence 'rolled off bass'

2. Rolled off bass.
- There's still decent amount of bass, and that's already good enough for most songs that I've listened, but when it goes to the sub bass, they won't be emphasized. They just sound reduced to the point they sounded like 'rolled off' from the music. Those who really, really want those D E E P bass will not enjoy this, but since it sounds great overall, most people will definitely enjoy this regardless. Increasing the bass through EQ does help, but it still won't give out that D E E P rumble.

3. A clear, crisp, detailed yet not too harsh treble.
- Music sounds really good in general regarding this. Mids and highs just sound great without them overlapping each other. Some parts of the highs are bit too much for me, which can be solved easily by lowering it through EQ. When it comes to gaming, this really helps a lot to bring out sounds of footsteps, gunshots and other sound effects.

4. A spacious sound.
- If you never tried out an open-back headphone, the KSC75 is the best entry into experiencing the spacious and wide sounds that open-back headphones gives. The whole music, instruments just feels like it's around your head instead of being inside your head. Combine this with it's great sound quality, music listening just feels more immersive. For games like fps, gunshots and footsteps of other players sounds more accurate in terms of positioning, not just around left and right, but also more on front and back.

Sound isolation and leaks
Due to it's design, it's obvious that it won't isolate/block most sounds. Any typical noises like someone talking nearby, speaker playing a song, city noises, etc. can be heard while using it. This disadvantage really depends on your preferences and use cases, as I'm alright with it. It also leaks any sound currently playing, even at medium levels, so if you're listening to anything especially 'cultured' stuffs while someone's nearby, adjust the volume or find somewhere alone to listen

Extra: Mods
One of the things that impressed me is the plenty of mods that can be performed to the KSC75 to improve it's sound and reliability. One of the mods that I've done is the MMCX cable mod, where I made my KSC75 to accept detachable MMCX cables. Now, cable replacements are more easier to perform if the current one breaks. There's even a 3D printed mod for the adapter, which I've applied as well. It's relatively easy to perform this mod, providing that you have soldering experience. There are some other mods: Kramer mod, replacing the original pads into Yaxi pads and using Parts Express as a headband, all which help to improve the comfort and sound quality of the KSC75, and also which I'll explore into more depth someday.


The Koss KSC75 is the best clip on headphone, and is also the best sounding and the most comfortable headphone that I've used so far. All of these just for $20, which is totally unexpected and a very welcoming surprise. This is now my current endgame for music listening and gaming. Thanks for reading and have a good day ^^

Preface​

Admittedly, the first Koss product I’ve tried is their Electostat, ESP950. I found that headphone to have a distinct presentation when compared against the planar and dynamic driver headphones I’ve tried. It presents notes in such a lightweight fashion that I feel there’s a lack of dynamic impact of the different instruments and vocals being reproduced. It’s a weird feeling, I will say that. Regardless, I found the Koss to be generally good sounding overall, with decent tonality and good technicalities. Build quality is something left to be desired, but the comfort is top notch given it’s large pads and feather-like weight.

Well, I'm going full circle and going to one of their best known budget offerings - the KSC75. I’ve seen it recommended on different forums for budding enthusiasts on a budget, and often see memes about it as well (mostly on reddit). I’ve also seen Crin, one of the notable reviewers in the community, giving it high praises for its performance. With that out of the way, I will also be going over them and seeing whether or not they live up to what Crin and others have said about them.

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Accessories and Packaging​

Simple, efficient, and nothing flashy. In a way, I kind of like these types of no-frills, no attention grabbing packaging. It’s just simply open it, and use it - which in truth is what they’re supposed to provide, especially at this price point. You open them and you get the earclips themselves with the non-detachable cable and a small manual. Nothing else comes with it, although maybe my one wish is that Koss provides a detachable cable option for these at a higher price tag (maybe using MMCX or 2.5/3.5mm cable connector) - that would be a nice option to have.

Aesthetics, Build, and Comfort​

Well, I don’t know about aesthetics as these look like typical clip-on headphones that I see from the likes of Panasonic, Sony, or even JVC. They look weird when being worn, I’ll say that much. It won’t win any awards in making you look good.

Funny enough, I didn’t know how rigid or how far I could adjust the ear hook, and accidentally tore one of the ear clips apart from the main drivers by accident upon first opening them. I thought I had already broken it at that point, but then realized the design is a simple clip-on that can be re-attached. Nice - not something that breaks easily like other $20 unknown brands that sells earphones/headphones. You get more than what you pay for in that sense for this type of mechanism.

In terms of comfort, yeah they’re really comfortable, even more comfortable in a sense compared to the HD800. The sole reason being that these are simply so lightweight that the clip-on mechanism is hardly noticeable. I feel most ears would find this very comfortable, except maybe for the weird shaped or the larger than average ears out there.

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Sound​

I would be referencing Crin’s measurements as it appears to be closest to how I hear the KSC75. It doesn’t seem that these really need an amplifier and can work out of my Macbook Pro just fine, and without a noticeable improvement in quality when going with a dedicated amp like the iFi Micro BL.

For reference, the type of music I listen to are Alt Rock, Classic and Ballad Rock, EDM, English and Asian Pop, some hip-hop/rap, some acoustic, and OSTs. I usually listen anywhere between 60 dB - 75 dB.

Tonality / Overall Signature​

My first thought upon hearing the KSC75 was that there’s a noticeable lack of bass presence, mostly from the 80Hz to below, and it shows in the measurements. A severe roll-off from 100Hz and lower. However, it only gets better from there. The mid-range to treble balance is overall great! Although the higher than average upper-midrange can make vocals that hit this region a bit shouty, I would consider this excellently tuned overall. It looks like another headphone that I think I would agree with Crin’s description - this is a bass-light neutral in tonality.

If I break down each section:

Bass

• Definitely could use some more bass extension
• Bass is there and you can hear it, but it’s neither impactful nor has enough presence for a lot of modern tracks I listen to. It’s just there
• On busier tracks, it’s hard to distinguish the bass notes
• Overall, a clean bass presentation that doesn’t bleed into the midrange

Midrange

• Lower midrange seems almost perfect to my hearing, linear from around 200Hz up until before the 1kHz rise for the ear gain
• Male vocals and lower piano/guitar tones have good weight note and texture
• There is a higher than average upper-midrange, particularly in the 2.5kHz - 5khz region - which lends to a little shouty vocals that hit this region
• To add to the point above, it renders some vocals/instrument range that utilize this region to be slightly thin in note weight and come across as “intense” to put Crin’s words. But, I don’t find this flaw very detrimental for the rest of the midrange in my opinion. Disclaimer: Opinions may vary on this one

Treble

• Overall great balance - nothing triggers my sibilance sensitivities
• Maybe lacks the last bit of extension to give instruments more space in the presentation, a minor nitpick to be honest
• There’s a slight “grain” that’s noticeable for some very specific songs, but not for others, especially when the consonant range are being pronounced - but I think I would factor in the intense 2.5kHz - 5kHz region to play a part in this perception
• Overall the treble balance is excellent from 6khz and above

My only real complaint about the tonality is the slightly aggressive 2.5khz to 5kHz region, whereas I just need to lower that part down and the tonality is already perfect for me when listening to these (while adding more bass quantity of course).

Fantastic sounding pair from Koss, I can’t really complain about the tonality and I whole-heartedly agree with Crin’s review on this one. I know some of you don’t hear “ear-to-ear” with him and how he ranks certain IEMs / headphones - and I can understand that perspective to an extent. There have been a few models that he has rated that I don’t completely agree with, but for the most part, he has been accurate with respect to how I hear such headphones/IEMs.

Now, my only word of caution regarding the tonality is that aggressive upper-midrange area. If you are one who is aware of being sensitive to frequency spikes within that region, maybe this might trigger them. At this price point though, I don’t think you’d be losing really anything if you’d like to demo them from the likes of Amazon. This upper-midrange to treble intensity, mixed with the lower than average sub-bass to mid-bass impact, lends to the perception of finding them “bright” and “thin” sounding. I’m not one to argue with that notion.

Detail Retrieval (Resolution) and Dynamics​

At this point, I may sound like shilling them, but it’s hard not to when the product performs well and beyond what is expected at their asking price. Detail retrieval I find is competitive up to the average $200 range, meaning along the likes of the Audio Technica M50, Shure SRH750DJ, and the Sennheiser Momentum (OG). The KSC75 I find, is not as resolving to the likes of the HE-400/500, Focal Clear or HD800 though, as the finer details in busier tracks are harder to distinguish.

Dynamics also seems really good for its price point. There’s a good dynamic range when moving from the lowest volume piece to the loudest, while having a good attack of instruments. I will put it a bit behind the likes of something like the Hifiman planars, and further from Focal’s dynamic presentation. BUT, the transients are not too blunted and can make songs engaging, I will say that for sure.

Head stage and Imaging​

Surprisingly, I find the stage width here to be “average” - meaning I can perceive the stage width to be up to my shoulder length. On that note, imaging seems to be fine for me. I haven’t noticed any flaws that would deter from the overall presentation. It’s not a 3-blob type of effect, nor is the center image disoriented that could confuse my perception of where instruments are coming from.

One thing I’ll note is that the stage is not as “tall” or as “enveloping” as most over-ear headphones given their design of sitting on your ears and not completely covering them. These will never have the effect of the HD800 or HE-400 that covers my whole ear which adds to the immersion of the audio perception. If you value that immersive qualities that most over-ears bring, then I would not put this as a contender.

Timbre​

Most of the instruments and vocals sound correct to me, in that it sounds like I’m listening to a good set of speakers. The higher than normal peaks at 2.5khz - 5khz is what’s contributing to the slightly “shouty” quality of instruments and vocals that hit that range. Further, it can make weight notes sound thin when hitting this region, similar to hearing a singer live with an open stage.

I digress, timbre is correct for the most part. The upper-midrange shout is akin to hearing a live concert in an open venue, whereas my experience with that is the speaker set tends to present vocals and instruments “thinner” sounding. This part needs some correction and I'm glad EQ can address it.

EQ​

Really, the two biggest corrections I would apply to these are lowering that upper-midrange and increasing the bass region. For the entertainment of the community, I use the following EQ corrections to make it slightly “warmer” sounding:

Filter 1: ON PK Fc 35 Hz Gain 3.8 dB Q 0.52
Filter 2: ON PK Fc 69 Hz Gain 1.9 dB Q 3.46
Filter 3: ON PK Fc 2393 Hz Gain -2.5 dB Q 2.12
Filter 4: ON PK Fc 5746 Hz Gain -2.5 dB Q 2.41

You can play around with the bass values as you see fit. I would expect most who already love the KSC75 as is would find these EQ applied maybe “losing sparkle”, “ losing air”, or something to that effect. I get that, but I feel that’s needed to make them sound more ‘correct’ - although they already sound excellent as is and your ears tend to adjust to a tonality if you keep listening to it for a while.

The one thing I hear with the above EQ is that it adds some of that note weight back in the lower midrange to balance out the male / lower toned midrange instruments. I don’t notice any distortion when applying such EQ, so this is a big plus for them as well. The setting above simply makes them sound almost perfect to my ears in tonality.

One last note is about the bass setting above. I’m using that setting mixed with the iFi Micro BL XBass boost on - which lends the bass impact and quality to my desired preference. YMMV and you can try increasing/decreasing that to your preference. I haven’t increased it further than that and it may introduce distortion, so do it with caution.

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Conclusion​

I don’t think it’s fair at this point to be comparing these to headphones that are higher priced, because it’s already performing beyond that in terms of pure tonality. In terms of tonal balance and performance, I would pick these over the Focal Clear. One of the main reasons is that the KSC75 doesn't trigger my treble sensitivities like the Focal Clear does. Further, the staging and imaging is about on par between the two with the types of tracks I listen to. Where I would pick the Clear is when I’d like to listen to tracks and specifically look for better bass quality and dynamics - two qualities that the Clear has in spades.

To that end, I think these simply deserve the praise they get. The technicalities I find are also on par or even better in some regards than the majority of the headphones within the $200 price bracket that I’ve managed to demo or own. I can understand why Crin praises them highly, and it’s great to see Koss still selling these… thing.

They’re very affordable for the masses, can be modded for DIYers out there, and I think are comfortable for the majority given their design of simply hanging on your ear while being light - so no added weight or pressure on your ears. Putting in EQ on these also gives them the potential to sound better, and to my ears, reaching my ideal tuning for neutral.

Kudos Koss. Please never stop creating these. I’m slowly evaluating the reason for hanging on to higher end headphones like the HD80, although the HD800 still retains a party trick that is hard to ignore when switching between the two. For the types of music I listen to, these are simply great all rounders. I don’t really need to nitpick all the details, nor do I need to have the widest of head stage. Most of the time, especially while I'm working, I just want something that has excellent tonality while being comfortable, and these fit the bill just nicely.

If you’re NOT like me and are looking for better technicalities, I’m confident you’ll be able to find them as you go up the ladder. However, keep in mind that just because they have better technicalities, does not mean that they have a better tonality. Very few headphones I have heard thus far are better tuned than the KSC75, even when EQ’d.

The people I would NOT recommend the KSC75 to are people who are looking for a good bass impact or looking for sub-bass boost in what they’re listening to. Even with EQ and iFi’s XBass boost, I find it still lagging behind an EQ’d Elegia or HE-400 in terms of bass performance. So, there are those people that wouldn’t bother with these for that specific quality they’re looking for.

Now, my overall grade would be the following:

• Stock tonality - 8.5 / 10
• EQ’d tonality - 9.5 / 10
• Technicalities - 7.0 / 10
• Comfort - 10 / 10

I’ll be giving these my first 5 star review on head-fi. I may sound like I’m shilling (and I would think I don’t shill if you look at my previous review articles), but really it’s hard not to sound like one when price-to-performance is off the roof. If any friend or family is looking for a recommendation for a good sounding headphone/earphone, I will point to this thing first and foremost. Yeah, they’re that good, while not really looking that good on you, and I think anyone can shoot their shot with these without losing more than $30 USD.

Probably next on my things to try on the IEM side is the Sony MH755, which many also seems to praise. They’re a bit harder to find nowadays with a lot reported fakes being easy to grab in the market as well.

My biggest curiosity now is how does the Focal Utopia/Hifiman Susvara stack up to how well tuned the KSC75 is. I’m expecting big things for those TOTL models and simply being “technically” better won’t cut it for me.

• Non-sound
• Sound
• Comparisons
• Conclusion

Disclaimer: I bought this at my own expense at amazon.se

Price: 20-30 usd (I paid 30 usd)

Specifications:

Frequency response: 15-25,000 Hz

Impedance: 60 ohms

Sensitivity: 101 dB SPL/1mW


Accessories:

None


Cable: A simple cable that is the type that is on most mainstream products. Durability should be fine due to the thickness but the weak point is most likely the connectors on the drivers themselves as they don’t have any strain relief there. It has a diagonal plug at the 3.5mm connector.



Build: The build quality is like a double-edged sword; it is plastic (not very high-quality plastic) but is also very lightweight due to it. Very minimal adjustments can be made in terms of adjusting the angle of the driver. Unfortunately, no L/R markings.

Fit: Very unique fit but no problems for me. Although it doesn’t fit secure enough to be used in physical activities.

Comfort: Extremely comfortable and almost weightless on my ears. Very little heat generation due to the fit (no clamp since it doesn’t have a headband). It shouldn’t be a problem even for hotter countries.

Isolation: Basically, non-existent isolation and it leaks a lot of sound, definitely not something to use in a public place like a library.


Setup: Ibasso DX160 (high gain, volume around 45), stock cable, stock pads

Lows: Very clean bass due to it being very tight/fast but extension and rumble is extremely bad so it is not suited for sub-bass focused genres like EDM, Hip-hop, Trance. Mid-bass on the other hand is better in quantity but is still lacking, but it is very suited for acoustic tracks.

Mid-bass: Metallica – fight fire with fire (01:11-01:52), Very good speed, tightness and texture so it sounds extremely clean and no signs of bloat at all. Quantity is fine for this track but I prefer a bit more so it is more fun. The (02:55-03:01) section is very good and you can hear the chopper very well.

Hiroyuki Sawano – Pretenders (01:18-01:47), Very tight and fast, but is lacking some quantity along with texture to make it fun and to make it more tonally correct (it needs to be warmer).

Sub-bass: Djuro – Drop that bass (01:15-01:30), Extremely bad extension and non-existent rumble. The punch is clean because of its tightness/speed but is also lacking a lot of quantity along with texture.

Will Sparks – Sick like that (03:08-03:22), Very tight and fast but is lacking quantity and texture.

Mids: Extremely high-quality female vocals and very good male vocals. Balancing between male/female vocals is leaning a bit more towards female vocals due to the overall tonality being on the brighter and thinner side. Male vocals are a step behind the female vocals in terms of quality, due to it sounding a bit too bright/thin. But both male/female vocals are very detailed and sounds very clean.

Female-vocals: Hiroyuki Sawano – OldToday (01:25-01:52), Stunningly good, the tonality is very good for this, thin but not too thin and not too bright. Vocals are very clean and detailed. Excellent timbre, just a little bottlenecked in terms of naturality due to the low bass quantity making it lack a bit of warmth for the instruments.

Yuki Hayashi – MightU (01:58-02:55), Extremely natural and tonality is correct.

Evanescence – Bring me to life (01:18-01:35), A bit too bright tonally and a tiny bit shouty.

Hiroyuki Sawano – Crescent (02:07-02:26), Is a bit shouty and too bright tonally.

Male-vocals: Hiroyuki Sawano – Pretenders (00:57-01:17), Needs to be a bit warmer for both his vocals and the instruments, but otherwise very clean and natural.

Hiroyuki Sawano – Scapegoat (00:57-01:17), Lacks some warmth but is very clean and natural.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), Not sharp at but is a bit too bright.

Deuce – America (03:03-03:16), Tonality is too bright.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Tonality on the violins are very good, but texture could be better. Cello´s needs some more warmth but is better textured than the violins.

Hiroyuki Sawano &Z (02:18-02:57), Very natural and clean sounding, but needs a bit more bass quantity.

Soundstage: Huge soundstage in both width/depth but is wider and is very airy.

Tonality: Bright-neutral with excellent timbre. Thinner note weight but not too much so it becomes analytical.

Details: Very impressive amount of details (and yeah, the tuning does have its inherent benefits to the technicalities).

Instrument Separation: No problems at all, very impressive (low bass quantity and very fast/tight certainly helps it a lot).

Music: Fate grand order Babylonia – Hero´s mission, sounds absolute fantastic with its natural timbre and the huge soundstage makes it epic while the technicalities can keep up.

Hiroyuki Sawano – Because we are tiny in this world, extremely natural despite the bass quantity being very low. Somehow sounds fun (with low bass quantity) and yet is very clean and detailed.

Songs that highlight the Headphone: https://www.youtube.com/watch?v=hsXur-NbfG8 https://www.youtube.com/watch?v=3jf_Z68c4LQ https://www.youtube.com/watch?v=vLhafvJvPUI https://www.youtube.com/watch?v=Ek7C5GurYOw https://www.youtube.com/watch?v=gk-mrXzjQo4 https://www.youtube.com/watch?v=8F_11HaH4mE

Good genres: Acoustic music, OST

Bad genres: EDM, Trance, Hip-hop, R&B



Comparisons:

Headphone: Koss Porta Pro, stock cable, stock pads

Bass: Djuro – Drop that bass (01:15-01:30), Better extension and rumbles much more on the Porta. While the 75 has a faster and tighter punch so it is much cleaner, texture is similar on both.

Hiroyuki Sawano – Pretenders (01:18-01:47), Bloated bass on the Porta, while it is very clean on the 75 due to its much faster/tighter bass. Texture is a bit better on the 75.

Metallica – fight fire with fire (01:11-01:52), While speed is somewhat similar, the Porta is extremely bloated due to it being very loose. To the extent that it almost sounds like sub-bass rumble instead of mid-bass punch. Individual bass strikes are meshed together on the Porta while it is extremely clean and detailed on the 75. No contest at all, the Porta is literally dying from blood loss (bass bleed).

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), Tonality is much better on the 75, while it is too warm and dark on the Porta. Much cleaner and detailed on the 75 as well.

Evanescence – Bring me to life (01:18-01:35), Tonality is much better on the 75 and is much cleaner and detailed. The bass on the Porta is affecting the tonality very bad (too warm).

Hiroyuki Sawano – Scapegoat (00:57-01:17), Tonality is more correct on the Porta, but is much cleaner and detailed on the 75.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), Tonality is better on the 75 and is cleaner, more detailed and more natural.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Tonality is a bit better and more textured with the cello´s on the Porta. Violins are much more tonally correct and textured on the 75. Much cleaner, detailed and natural on the 75.

Hiroyuki Sawano &Z (02:18-02:57), Better tonality, detail, cleaner and more natural on the 75.

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), Soundstage, detail, instrument separation and timbre are on another league on the 75.

Overall: The 75 beats the Porta on pretty much everything except bass quantity. So, for bass focused genre like EDM, Trance, Hip-hop and R&B, the Porta is more suited for those. While the 75 is better on everything else. Although if you want most fatigue-free sound, the Porta is better due to having both lower treble quantity and much more bass quantity.

Earbud: NiceHCK DIY MX500, stock cable, full foams

Bass: Djuro – Drop that bass (01:15-01:30), rumbles and extends a bit more on the MX500. Punch quantity is also a bit higher on it. The 75 is tighter, faster and has a bit more texture.

Hiroyuki Sawano – Pretenders (01:18-01:47), Quantity is similar but is tighter, faster and more textured on the 75.

Metallica – fight fire with fire (01:11-01:52), a bit more quantity on the MX500 but faster and tighter on the 75 while texture is similar.

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), Similar tonality but much cleaner and more detailed on the 75.

Evanescence – Bring me to life (01:18-01:35), MX500 is a bit more tonally correct and less shouty.

Hiroyuki Sawano – Scapegoat (00:57-01:17), more tonally correct on the MX500 due to having some more warmth (due to having a bit more bass quantity).

Treble: Linkin Park – Shadow of the Day (03:24-03:42), less fatiguing on the MX500 and also more tonally correct.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Cellos are more textured on the 75 but similar tonality and timbre. Violin timbre is a bit better on the MX500 but has similar tonality and texture. Cleaner and more detailed on the 75.

Hiroyuki Sawano &Z (02:18-02:57), Tonality is better on the MX500 and sounds more natural, while it is more detailed and cleaner on the 75.

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), Soundstage, detail, instrument separation, imaging and timbre are better on the 75.

Overall: The 75 has better SQ and technicalities but is less versatile due to it having less bass quantity (not that the MX500 would suit bass heavy songs much more than the 75 though…). The 75 is perceived as being brighter overall all due to the bass quantity but treble quantity should be similar.

Headphone: Blon B20, Brainwavz Sheepskin Leather Memory Foam, YY 16 core cable 3.5mm

Bass: Djuro – Drop that bass (01:15-01:30), Extends and rumble much more on the B20. Texture is a bit better on the B20 and has more punch quantity. Tighter and faster on the 75 and is cleaner and more detailed.

Hiroyuki Sawano – Pretenders (01:18-01:47), Similar quantity, but tighter, faster and more textured on the 75.

Metallica – fight fire with fire (01:11-01:52), Faster and tighter on the 75 while texture is similar. Individual bass strikes on the B20 is pretty bad and not very accurate.

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), Tonality, details and clarity is better on the 75. But the difference in timbre is very big, the B20 sounds very unnatural.

Evanescence – Bring me to life (01:18-01:35), Tonality is a bit better on the B20 and is less shouty.

Hiroyuki Sawano – Scapegoat (00:57-01:17), Tonality is a bit better on the B20 due to it being warmer, but again the details, clarity and timbre is much better on the 75.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), Tonality is a bit better on the B20 due to it being warmer, but again the details, clarity and timbre is much better on the 75.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Everything is better on the 75….

Hiroyuki Sawano &Z (02:18-02:57), Everything is better on the 75….

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), Soundstage is deeper on the B20 while width is similar. Details and instrument separation are better on the 75. Imaging is similar. But the timbre is disgustingly bad on the B20, extremely unnatural.

Overall: DO NOT BUY THE B20! It doesn’t offer anything over the 75 despite the giant price difference and on top of that it also doesn’t have the godly mids that planars should have while it has a very unnatural planar timbre across the entire range.



Conclusion: In conclusion, for acoustic music listeners, the Koss KSC75 is a 5/5. But If you aren’t only listening to acoustic music, then it is a 4.5/5 because the bass quantity is bottlenecking it a lot for other genres. Thanks for reading.

Reference/test songs:

Wanted to share with you all my history with modding these.
 
FIrst, I saw the kramer mod and figured I could do a little bit better. (easier and than drilling a lot of holes)
I decided to fully open this puppy up. 
I went to the dollar store and got a stainless steel sink strainer. This woudl become the new baffle.
I removed the original black plastic baffle from the headphones.
I cut circles of metal sink strainer and epoxied them to the front of the headphone.
Now the speaker had a uniform opening to breath.
 
After doing the above mod, I put the foam ear pads back on. They were quite a bit brighter than I wanted. So that is why the original Kramer mod is the way it is!
 
Next, I bought some knock of sennheiser px 200 ear pads. I figured these move teh speaker a bit away from the ear. Better sound balance and sound stage I thought! I installed these and they were much better balanced and soundstage might be a little better a little deeper. BUT the midrange now has a honk.
 
Time to modify the px200 pads. I realized that the pleather was covering 3 very large side vents on the back of headphones. I cut a bit of the ear pads to unblock these vents and bam. They sound superb now. I would suggest for anyone wanting to mod the pads to perforate the pleather. maybe stabbing it a lot with a needle? micro hole punch? These pads are a lot larger then the stock foam, you will probably need to bend the ear hook to accommodate. 
 
Finally, if after doing the above, they are still too bright for you, you could always install the foam ear pads underneath the px 200 pads. let me know how that goes for you.  
 
Silly Side Note: I admit I am crazy. Before I made these modded Koss, I bought some hd6xx, fostex ebony (stock, zmf and brainwaves hybrid pads) and schiit jotunheim  w/ DAC. I did not like the hd6xx at all with the jotunheim, sold them. I liked the fostex and the effortless bass. The stock ear pads suck because uncomfortable, the hybrids also suck because treble peaks, the zmf pads work nicely. Yet still, I am selling the ebonies and the jotunheim. As of now, I am perfectly content with these Koss and my LG V10. It's just a much more simple setup. I am planning on getting some custom iems to supplement the koss because these things are so ugly I won't go outside with them. For biking and working out I have the se215 on a westone mmcx bluetooth cable. 

 
Costing me only £16, these are one of those bang-for-your-buck kind of items in the audio world.
 
Build Quality, Fit & Comfort
 
The packaging reflects the budget-fi nature by looking like something hanging on a checkout aisle at a Walmart somewhere. The build itself is expectedly not stellar, the cups are made of hollow plastic with holes. The foam is not particularly soft but not particularly rough either. The cable is another issue, being really flimsy and rigid. I would not recommend being too rough with the cable or headphones, as it does feel like it’s prone to fraying – and generally being one caught door handle away from being pulled out of the socket.
 
Because of such build materials, these are extremely light and do not weigh down your ears. They stay in place quite well too thanks to the clips, but don’t expect the wearing experience to be one where the headphones disappear on your head – I’m always aware that they’re on me due to how they sit, balanced on nothing but your ears.
 
Sound
 
The main draw of these headphones is the price-to-performance ratio. The sound is very, very impressive for its price range and form factor. The bass is punchy and has impressive extension for being such a seal-less and light fit. While I can’t say that I preferred EDM with the bass performance, it was certainly stellar for rock and metal music – with kick and double kick drums ringing out clearly in the mix along with the bass guitar, when it came to the low end. I would not characterize the bass as bloomy either, it does not overstay its welcome in more delicate genres of music. However, because the bass is of this nature, and also because there’s no real seal, wearing these in public makes the bass quite anemic – with it becoming a substantially brighter headphone.
 
The midrange is very, very clear and impressive. Listening to Simon and Garfunkel’s The Sound of Silence, the original acoustic version, shows off just how clean vocals can sound on the KSC75. Quite the contrary to the more forwarded mids on some headphones, the midrange of these are actually a little recessed – leading to a remarkably effortless transition from the bass to the midrange, something that I found lacking in both the Sennheiser Urbanite and Beats Solo 2 – which are both headphones that are several times more expensive. However, despite the impressive nature of the Koss in this regard, do not expect a very “natural” or full-bodied sound from the midrange – it actually has an artificial nature to it and a bit of grain. But, for its price, it is the best I have heard yet in open-back on-ear headphones.
 
The treble is probably the most impressive frequency of these headphones to me. I usually prefer a bassier and more mid-forward sound, but I could not deny just how much these headphones breathe. Stringed instruments such as acoustic guitars and violins have so much air around them – with the treble being very well extended without reaching immensely problematic peaks. Due to this extension and the slightly subdued nature of the mids, I would actually say that this headphone is bright overall – despite the punchy bass. However, as with the midrange, the treble is more metallic sounding than natural – but again very satisfying and impressive for its price. I will admit that I do prefer using the Ibasso DX80 digital-audio player, with its slightly warmer and treble-rolled sound signature, with the KSC75 rather than my SABRE DAC based AUNE M1s, which is a bit brighter. I also tried it with my VE RunAbout Plus portable headphone amplifier, but headphones do not really need to be driven as they can sound great out of a smartphone.
 
Another quirk of these headphones is that the soundstage is not very large by any means – which surprised me a bit due to how little they isolate and how punctured and open the cups are. The imaging is largely a miss, with the emphasis of sound reproduction being squarely from the left and right channel instead of projecting in a larger space. Due to this, songs with a lot more layers, tracks and tones can find themselves without enough room to truly shine on the KSC75 – but most songs are not of the nature where it would truly bother a listener using these for what they are intended, which is casual listening.
 
Conclusion
 
Probably the biggest compliment I can give these headphones is that I am critiquing them as if they cost above £100. They go neck to neck with many headphones several times the price on a purely sound quality basis – and even leave some more premium offerings in the dust in the same regard. I personally love when I encounter anything with this price-to-performance ratio in any hobby that I have – not just audio. With that in mind, I can strongly recommend these to anyone reading this review.
 
One final thing though, I did notice that it said on the bottom of the packet that some chemicals used in the construction of these headphones can cause severe health problems, such as cancer, according to the state of California’s regulations. However, I am told that Californian requirements are very strict, and the state has a long list of chemicals that receive this classification – deservedly or not, so make of that as you will.
 
 
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Had these, but sold them when I got a pair of KSC50, which gave me a much more enjoyable and clear sound.
The KSC75 had very little bass impact, cut-off early in the treble, poor detailing in the sound.
Both the KSC75 and KSC50 have a problem with comfort over a longer time of use, the clips make my ears tingle and hurt!
But for a short listening session when I want some "open" sound on a vacation, the KSC50 is usable.
They do provide the bass and detail that the KSC75 does not.

I bought these after reading so many positive reviews and I must say it's disappointment for me.
I tried them on Lenovo X3A40, Xonar ST and Xonar ST + Dispre v4. Many people says they are balanced with nice voals, highs and not so good bass. Well bass is ok for me. Not too much bass like Porta Pro (which I own too). Mids are slightly behind bass and trebles in compare of my AKG 701, Yuin PK1 and PK2, Ety ER6i, Hifiman RE-0. Highs are there for sure. They are sparkling but it sounds soooo rattling. Specially percussions, cymbals. Highs are worst part on these headphones for me and I like trebles. I like lot of trebles, I like sparkling trebles or even agressive trebles are not big problem for me but those from KSC75 are just ... yuck. Wierd thing is they sound good in rock music but are horrible in electronic music or classic music. Vocals sounds like placed into higher frequencies but overall they are nice. Soundstage is not big but separation is OK. I don't like sibilance on KSC75. For so cheap headphones KSC has a lot of details. Also balanced sound is not what I imagine when I'm listening KSC75. Isolation is bad but that's no surprise. Guitars sound nice in KSC75. Porta Pro has more energetic sound, more enjoyable except those bass.
Overall KSC75 are fine headphones but not for me. I like smooth detailed sound like PK1. These sounds more like PK2 with rattling highs, much smaller soundstage but better bottom mids.
I was listening to Faithless, Redhots, Dire straits, Lenka, Die Antwoord, MDK soundtrack, Fatboy slim, Daft punk and something more from Tidal after 12-15 hours burning.
PS: graphs about Audio Quality, Comfort, Design and Value are not like I set so don't look on them.

I am gonna start this where it should. These are the best thing in audio I have found at the price-point. I recently took all the headphones I have access to, and basically did a shootout. For audio quality, these came in third out of about a dozen. The Koss KSC75 came out ahead of the Sennheiser HD558, G4me Zero, G4me One, Monoprice 8323, and some others. Purely objectively, these are crazy for the price. (The two ahead of it were the Philips SHP9500, and the Superlux 668b).
 
The Koss KSC75 are quite comfortable for a clip-on. They weigh about as much as you would expect. The ear-touching thing is not nearly as objectionable as I had guessed it would be. As others have said, switching to a headband style would not be difficult at all. My only complaints with comfort and fit are how the clips dig in a little after a while, and they are a bit odd to center on your ears. This is entirely due to being clip-on.
 
The build quality is low, This is to be expected with anything at this price point, but has to be noted. The plastic backing is cheap, the foam padding is cheap, The cable is comparable to that of an old Walkman charger. The cable is awful. The cable, however, is a good length for portable use, and does terminate in an angled 3.5mm jack, which is good. The ear clips are cheap, and are just plastic. The wire supporting the clips are slightly different sizes on mine. One clip sticks out, and back a bit further than the other. The Koss KSC75 passed the shake the head around, jump, run test as well. These do not fall off my ears, but keep in mind my ears give plenty of surface area to hold on to. Overall, It is what you should expect for the price-point.
 
Now for the sound.
As mentioned before, these beat out some Sennheisers in my audio quality shootout. The sound is inviting enough that fatigue is not much of an issue. The clarity is great. Highs and mids are fairly well balanced with a few peaks and valleys. Vocals are great, but don't stick out so much that it becomes a problem. The bass is entirely dependent on environment and positioning. Overall, I neither find it lacking, nor overwhelming. The is not particularly loose or tight either. Soundstage is good, and the Koss KSC75 passed the CS:GO test with flying colors. These are extremely open. They get the double in the open catagory. Not only are they on ear, they are open backed, and use thin foam pads. The sound signature I would describe as similar to the SHP9500 with a bit more bite.
 
I figure I should start picking a song for each pair of headphones I review to give an idea of what sounds good with them.
Feature song: human - Christina Perri
 
 
Conclusion: The Koss KSC75 are hands down the best (imho) for their pricepoint. The Superlux 668b/ Samson SR850 is objectively better, but is much less inviting, and more cold. Still, I prefer the Sennheiser hd558 sound to any other option I have tried as of writing this. If you are addicted to headphones, or just need something open, cheap, and sound quite good, I highly recommend these.
 
I do all my testing with a FiiO e10, and all kinds of audio files. Please feel free to leave feedback, suggestions, questions, and especially recommendations. All these lower price headphones are a bit of a gateway drug to the world of audio. 

Read the others

 

eargasm

First that all, I called them Pieces of ****, because they look incredibly cheap and ugly, but they sound really good. They remind me a lot to the 668B, both have a fast bass that lacks Sub-bass (On the KSC75 that lack is worse), both have a sort of dry timbre, and both have great highs (Depending on your tastes you might find 668s highs a little bit too bright). To be honest, I find the KSC75 highs a little bit lacking. xD

Soundstage is very good, it is a step back of my 668b's soundstage.

Their clips are comfortable, but It takes a while to put them on. However, you can buy "Parts Express Mini Stereo Lightweight Headphones" on Amazon and use its Headband on KSC75s.
Overall, for 15$ You wont believe how good they sound.

Edit: I´m updating my reviews, I have to add that my KSC75 died (6 month ago) I´ll try buy a pair or even two pairs next year. Also I had the opportunity to try others portable headphones like HD202 and UE4000, and really, the KSC75 destroy the HD202s in almost every way and its on pair with the UE 4000.

UE4000s destroy the KSC75s on timbre and Sub-bass, However soundstage is wider and bass is faster on the KSC75. (I think this comparison is a bit unfair because you can buy almost 3 pair of KSC75 for the price of one UE4000).

Really, even after 6 month without them I cant still believe how good they were, and their biggest problem is how my KSC75 died, the died because their drivers themselves died (Not the outer cable) (It seems that the internal thin wires of the drivers broke up due to knocking).

I was looking for some headphones under $50, went through hell lot of reviews here n got confused about everything. Then somehow the browser showed few auto suggestions n I found these gems.
I read in almost every review that these are the cheapest n best earclips in the market. Well they are best but not that cheap in India especially when the exchange rates are so high. I got them for $25-$26 shipped to India through ebay.
Packaging:- The packaging was good, simple, nothing much to talk about.
Build:- They look flimsy n build quality is questionable. The cable is so thin n so ordinary, I have to be very careful while wearing them.
Comfort:- When I first wore the , I felt they are loose on my ears, so I tried to adjust the clips by slightly bending them. It takes time to adjust them in the beginning but after a while you get used to it.
Sound:-
Bass:- When I first listened to them I found the bass bit muddier. After burning them for 20-25 hours they opened a bit. I would say the bass is soft n punchy at the same time. You cannot listened to them on high volume as they start to rattle. I think these are made for soft listening levels.
Mids:- Some say they are recessed but I don't completely agree to it. Its true that they don't have forward mids but they are not recessed for sure. Mids are very clear, airy n pleasant for my choice.
Treble:- Highs are the most beautiful things on KSC75. Yes they are grainy but in a positive way. They are crisp,clear n I'm loving them. Highs have got nice extension.There is no sibilance whatsoever. In fact after listening to them I started feeling my Soundmagic E30 are bit sibilant too.
Isolation:- KSC75 are open back earpads, so you cant expect isolation from them. They are nice to wear at home or at gym but certainly not for wearing them on the streets if you live in noisy places like Mumbai. I tried wearing them in trains but i was completely disappointed (Don't compare trains in Europe with Mumbai local trains)
Conclusion:- KSC75 are the best deal out there for the price for sure. Sometimes I prefer them over my RE262 just for the love how energetic they sound even at low volume.(RE262 lovers please don't kill me for that, I love my RE262 a lot too, and quality cannot be compared)But it's just the characteristic of KSC75 that you fall in love with them. They look funny on the street. I look like a character from 1970's science fiction film. But I don't care about it as long as I'm enjoying the sound of it. As almost everyone said earlier, they are must have headphones and everyone should own these at least once in your life.
 

 
 
My simple tiny set-up-Cowon C2 + Fiio E6 + Koss KSC75:-

I bought these KSC75 clips because I lost my modded Koss UR55 and I read oodles of praise for them online. At first I was skeptical because they are very flimsy looking and they are often compared to the Koss PortaPro which sounds muddy in my opinion. So I tried them on and I was immediately impressed by the overall balance and airy sound. Everything sounds so natural and forward, and it's really easy to separate vocals and instruments. I really like these with pop and rock music. The KSC75 crush the PortaPro. However, I must say that the treble feels grainy at times, especially with shimmering electric guitars (typical in post-rock). Another complaint would be that they look super dorky on your head, especially next to the PortaPro which is very stylish. 
 
I think that the KSC75 would almost better the Grado Sr60i, if it weren't for that grainy treble. They are that good. 

They have good old fun sound signature, very engaging and very dynamic. I found mids are a bit too recessed for my tastes and affected by the low region unfortunately however from a cheap can like this, I don't expect the separation of HD800 obviously. Treble is nice, sparkling very detailed and crisp. Bass could be more controlled but it does its job, it has a strong, punchy bass and when the song calls for it, it knows how to give 'boom' effect.
 
So what do we have here? Very good sounding on ear headphones which can easily compete against 100 euro price range. Is there a problem, you bet! Some people seem to like the design and clip system but I totally hated it. I am currently looking for a chance to make a headband mod otherwise it is too painful for me to wear it longer than 20 minutes. Also I keep on playing with the clip because it doesn't fit correctly and keeps on moving around. Design-wise, unfortunately they are failed in my experience.
 
At this point, you probably know that they are open back cans, so they don't isolate and they leak sound quite a lot. If you want to hear your surroundings, that's good for you but pay attention, you might disturb people around you.
 
They are also easy to mod, I saw already Kramer mod and headband mod. If I can do the headband mod (looking for a headband donor cheapo headphone) I will continue with the Kramer mod too.
 
Also, they might need a little bit more power than your usual average consumer targeted iems/headphones.
 
I have problems with comfort but I like the sound, I will try to mod them to keep it, otherwise no go for me. I bought these ones to use in gym not as a main headphone and for 15 euros, I think they punch way above their price. However, if I fail modding, probably I am gonna order PX100-II to use at gym.
 
So if you are looking for can to use in the gym or outside running they are good. Also if your budget is tight, I can still recommend them since they are kind of giant killers. Just be sure that you can handle the clip system or do a headband mod.

....... as a young lad, some 30 years ago, when I first got into headphones and placed my order from J&R music world, waited in ernest for that UPS truck to deliver my pro4AA 'digital ready' headphones. I'd just gotten my new technics CD player and copys of police-ghost in the machine, billy idol's rebel yell and dark side of the moon. before cd's all we had to listen to for portable music was via tdk and maxell tape through a sony walkman that were dubbed and traded from friends lp collections. There was only a few cd offerings at first and boy was I excited about the dynamic range of the digital sound and really liked the idea of instantly skipping to my favorite song and lack of cracks and pops that were the norm on my turntable.......but I digress, the Koss sound was a good one even back then, but the ksc75 reminds me of what I like about vinyl whereas the digital ready pro4aa was a less organic sound. The ksc75 is an accurate and natural sound with the exception of the top end which is inaccurate and is thrashy. Cymbals will not sound right for example. This may help with some amplification but who buys $20 headphones to use with $400 amps? In any case, I've not found amps to completely solve the high end problem......while these headphones have a nice analog'y sound, there's nothing here that will astound or impress for anyone 'into headphones', unless you really just like to sit down and listen to your favorite music and are on a budget. Eq the treble down a notch and enjoy....... 

If there are better sounding headphones in this bracket, they sure aren't available to the public yet! The KSC75s just might represent the apex before the downslope of diminishing returns.
 
The sound: Very fun and engaging all-purpose sound. The bass is certainly present, although far from basshead territory, the mids are maybe a little recessed, but they sound just great all the same, and the treble extends nicely without a trace of sibilance or harshness. 
 
Design: Probably the only downside to these guys. The driver covers look super-cheap and the earclips make these the most uncomfortable cans I've ever used. Granted they do get more comfortable as they loosen up. I however, would recommend to anyone who experiences discomfort (which will most likely be anyone with ears) buying a  partsexpress headband to use with the 75s. Super easy to install and totally relieves all of the discomfort.
 
Value: Like I even need to go here. For under $20 you can purchase earphones that rival in sound quality, IEMs and on-ears in the $75-$150 range. When's the last time you saw a frequency response of 15-25k Hz for phones that cost less than $100 brand new!? Such a great deal! At the very least everybody should try these just once. I was able to pick up mine for $5 a pair as they were recently put on clearance at a local office supply store! Two pairs of $100 sound earphones for $11 including tax.
 
It should  be mentioned that the 75s don't come with any accessories like 1/4" adapter or case, but honestly if you need a case, you can find something cheap.
 
If you need some beaters that are gym-ready, office-ready, or just walk-around ready, look no further. Plus they won't break the bank! Kudos to Koss!

I bought these this week from amazon.co.uk for £10 including delivery. That's US $15.

edit: I've changed my rating and feel more positive about these than when I first wrote the review. See the comments after the review.

Packaging, appearance, warranty, euro-nanny knows best:

Mine arrived in the small European packaging box, branded as Pulse clips as well as "Koss high performance on-ear clips". With the clips came the Koss warranty and the euro-nanny-state leaflet on waste disposal. The phones are the silver plastic Koss branded items everyone knows.

The lifetime warranty is valid but irrelevant because shipping costs from UK will exceed the value of the product. But I do very much appreciate a company that has faith in its products and is known to honour the warranty.


Construction, design, materials, euro-nanny isn't done yet:

The slightly odd design works extremely well. With a little careful bending of the plastic-enclosed metal clips I got a good snug fit and no discomfort. I wear spectacles with ultra thin titanium frames and there is no difficulty. With more conventional specs there could be obvious problems.

The silver plastic parts are a blast from the past, looking like cheap stuff I remember from the 1980s. But I don't care. The materials clearly do the job and don't cost much. The cable is unremarkable, 4' long with a straight jack. When I go to plug it in I notice a tiny sticker attached: it's another euro-nanny warning not to dispose of electrical items in household waste. Yes mummy. No mummy. There is a committee in Belgium worried that the first thing a customer will do is cut off the non-detachable cable and throw it in a landfill. I won't do that because I like to listen to some tunes while burning old tires and drunkenly shooting at endangered species in the national park at 2 am.

Everything seems properly assembled and when I press play it works as intended.


Using with portable players:

The Koss KSC75 need much more power than typical budget portable headphones, IEMs or buds. With a player like the Sansa Clip+ you'll probably need to run it at or close to maximum volume which means battery life is reduced. This is especially true for well produced music such as from before the modern loudness war fashion, and any classical music. My iRiver H140 and H340 players put out about a third more voltage than the Clip+ and do a much better job of driving these Koss earphones but unless you're in a quiet environment it might both be not enough and also too much because.....

Isolation:

There isn't any in either direction. If you use these on public transport everyone will hate you. In the street or a noisy workplace you'll hear everything around you and anyone close by will hear your music. The natural thing to do can be to keep raising the volume. This is the road to hearing damage. Compared to using IEMs I find myself running the Koss 'phones at dangerously higher levels and still finding the background noise doesn't let me fully enjoy the music. Beware.

Sound Quality:

It has some bass, which is a welcome contrast to similarly cheap buds and IEMs. I've listened to some orchestral music, some harpsichord pieces, some choral music, some heavy rock and some bass heavy electronic stuff. The sound is nicely balanced and generally enjoyable. The biggest defect is poor stereo imaging. There is no possibility of imagining oneself being present at the performance. There is no convincing illusion such as I get with a really nice recording and my Shure SE215 or Sennheiser CX 95. With the Koss 'phones the impression of sound is close left, close right and a slightly recessed bit in the middle. Some of this is due to the lack of isolation. For the last few years I've been using IEMs and closed and semi-open headphones. I am really surprised how background noise such as the rumble of traffic from the street below or a kitchen or bathroom extractor fan might not be loud enough to dominate the music but is enough to really kill the dynamics and imaging in a fully open 'phone.

The above might sound overly critical but I'm trying to describe the experience without allowing the price and value to totally colour my opinion. It's true that the Koss KSC75 is still unambiguously better than any bud or IEM included with any device I've ever bought.

Is it worth £10?

Yes, but I might not have bothered if it had been £15 and I definitely wouldn't pay £20 because for £30 I can buy Sennheiser PX 100-II that have much nicer sound, work better with low powered portable devices, are made of nicer materials and come with a carrying pouch. I would also hesitate to recommend these to anyone because the tendency to keep raising the volume to dangerous levels is hard to avoid. Because you can get a better sounding headphone at £30, and better sounding IEMs at less than that, the Koss is running out of selling points and has too many drawbacks. The most attractive feature is probably the clip-on design which is great for runners and people working out and those who won't or can't use IEMs.

It's about 9 pm here, the traffic noise has died down and I'm starting to enjoy the sound much more. And that's why these are hard to recommend as portable 'phones: they only make sense in quiet environments where others won't be disturbed. I expect to mostly use them with my PC because the USB soundcard has enough power to drive them properly and it's good to still be able to hear voices, phones, the doorbell and so on. These are also good to use with a mini system or domestic portable.

Conclusion:

As odd as they look. An idea whose time has come and gone. Worth £10 or £15 but not giant killers any more.