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.
Pros - Punchy bass, very clear midrange for its price point, airy treble, light, easily driven
Cons - Extremely poor build quality, the Quasimodo of headphones, may possibly cause cancer?
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.
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.
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.
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.