[Mang Domeng]

'Ello Head-fiers,

I wanted a pair of good workout clip-on headphones, and after much digging here I (like many probably) grabbed a pair of Koss Ksc75 from ebay for around $20 all included. The packaging seems completely genuine but...

The sound it produced is suspicious, the treble is surprisingly clear but not painful, the mids are fine, but the bass is problematic on both sides. Whenever I crank the source (I tried a laptop source, a sony stereo source, and a sony walkman source) to an appreciable volume, the base and vocal in songs with beats start becoming severely distorted; it sounds like a cross between cricket-chirping and metallic oscillations. This really kills the sound fidelity and makes it unbearable to listen to.

Regardless, I later committed and applied the Kramer mod on with success, overall the sound DID improve but the distortion was still there. It seems to be a driver problem.

Has anyone else owning a Ksc75 experienced this phenomenon? If so, is it remediable or do I have to return it for another one?

Currently I'm burning it in with some beat-heavy songs, hopefully that'll reduce the chirping distortions but if not, I'm at a loss.


Thanks!

I noticed the same sound in my left earpiece when I play bass-heavy tracks. I think I found the solution to your problem. I just tried doing a quick blow of air with your mouth on the driver with the foam on it, you will hear the driver diaphragm will press a bit. After I did that the rattling, chirping sound on the lows are gone. I was already considering replacing the drivers with my damaged kph30i but since it is fixed I will save the other driver for another mod. Hope this will fix your problem after 9 years. Cheers!

 

[DivineCurrent]

@jerg I know this is an old thread, but I am experiencing this same exact thing chirping thing with two paris of KSC75s. It's kind of like a fluttering effect like the driver is virbating something inside the enclosure. Koss apparently has not fixed the issue. It is less pronounced with stock pads, but I like using Yaxi pads and that's when you really hear this chirping effect. Only with bass heavy songs with hard impact. Too bad because with Yaxi pads and EQ I think the KSC75 is one of the best on ear portables and sounds like an $100+ headphone.

 

[Timoteew]

@jerg I know this is an old thread, but I am experiencing this same exact thing chirping thing with two paris of KSC75s. It's kind of like a fluttering effect like the driver is virbating something inside the enclosure. Koss apparently has not fixed the issue. It is less pronounced with stock pads, but I like using Yaxi pads and that's when you really hear this chirping effect. Only with bass heavy songs with hard impact. Too bad because with Yaxi pads and EQ I think the KSC75 is one of the best on ear portables and sounds like an $100+ headphone.

This was the only downside of the KSC75's for me, I actually found it most prominent with sax and clarinet in jazz music. Almost like a sonic strobing effect... hard to describe exactly. FWIW this 'chirping' sound is not present on my KPH30i or portapro.

 

[DivineCurrent]

This was the only downside of the KSC75's for me, I actually found it most prominent with sax and clarinet in jazz music. Almost like a sonic strobing effect... hard to describe exactly. FWIW this 'chirping' sound is not present on my KPH30i or portapro.

Interesting, yeah I noticed it is neither on the KPH30i or portpros when I compared. The bass also sounds a lot tighter and more controlled on the porta pro. It is darker than I’d prefer, but Yaxi pads bring forward the highs to a similar level of the KSC75 so you can get best of both worlds with bass and treble extension.

 

[DivineCurrent]

Update: I tried my other set of KSC75s again just to make sure, and somehow they don't exhibit the chirping problem I was having before. But my first pair does. There's definitely some kind of unit variation here when it comes to the driver. Or perhaps something got stuck inside both drivers of my first unit. Anyway, I ordered another one just to make sure it's not a fluke.

 

[haudaikuwa]

I bought three and they all chirp and rattle. Was going to take back the two, but got only to taking the other one back. I thought I would use it for research purposes at some point.