[bennyprofane]

I find these foams perfect: http://www.ebay.de/itm/2-Ersatz-Ohrpolster-53-mm-zB-passend-an-Koss-Porta-Sporta-Pro-Kopfhorer-/130866048343?hash=item1e78396d57mM5HSm8COZLAeA9XbS0ohJA (They're bigger and softer and work nice if you want to use a headband)
 
And these headbands worked perfect for me: http://www.amazon.de/HCH-ECO-10-Stück-Einwegkopfhörer/dp/B00XL318HW?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00
 
This is how the finished headphone looks: http://imgur.com/CKvYtVQ
 
I really love them and they sound so much better than my $250 Sennheisers which were also very uncomfortable.
 
 
 

  Greetings all!  I know this is an old thread, but if anyone stumbles across it I thought they might find this interesting.  Recently I decided to give the KSC75 a shot and was thinking of doing the Kramer mod when I decided that instead of drilling holes in the stock grill, I would 3D print my own grills to replace the stock ones.  I can gladly answer any questions about them.  I think they sound pretty good (especially version 4...V3, not so much though).
 
stock vs v1-3:
http://imgur.com/a/GFHRq
 
V4:
http://imgur.com/gallery/imfXBx1

That is really nice. Is it possible for you to post the 3D print "files" (not sure what it's called) so that I can reprint them?

 

[bennyprofane]

I modded both the KSC75 (which are same as Sporta Pro) and the Porta Pro. The Porta Pro have better bass but I still really prefer the KSC75. The sound is clear, rich and "3 Dimensional", they're just a lot of fun and also perfect for watching movies.
 
 
Quote:

  Alright so I did the kramer mod with my Sporta Pros and I seem to be getting lower volume/less bass from one side...
 
I don't think I touched the drivers at all, as I see no dent and I barely touched the cables.
 
Any idea why this could be?

 
I did a lot of them because so many friends of mine wanted them and there most be something really wrong with your headphones, I have never experienced this.

 

[Decommo]

Can anyone help me? I have Koss PortaPro and I applied Kramer Mod on it. I love the headphone but it has too much bass. I am thinking to get grill cover part and apply mod again but would like to tame the bass and increase mid & high. Is it possible to achieve this? If so, what mod do I need to do? Any suggestion would be greatly appreciated. Thank you.

 

[Decommo]

 

   
Wow great work with metal mesh! Did you use the original grill for the rim? Or is that some other material? If so, please let me know what you used. Thanks
 
The Kramer mod didn't do much for me either AZNracerx1989. It's not the first time I read that the mod didn't seem to do anything to sound quality. 

 
I'm not sure exactly what you are asking, but here's a pic of the driver with metal mesh covering the driver:
 

 
I just removed the plastic driver covers, cut out the metal mesh to the appropriate size, and crazy glued it onto the driver rim. You would want to do a better job than I did, and try not to have any mesh-ends sticking out (like the ones at the bottom of the photo), because they get snagged on the pad material easily.
 
The metal mesh + parts express headband (to get the drivers tighter on the ear) makes for a fantastic sounding headphone. I still shake my head to think of how inexpensive these are and how good they sound. I have been listening a lot lately to my new ATH AD900X 53mm open headphones (first open backed headphones), which I think are awesome. But now I just tried the KSC75's on my laptop via the ELE DAC (amazing $20 usb dac) and my Fiio E11 portable amp to thow in a bit of bass boost ($40), and they really are producing a ridiculously good sound. If the ksc75's had been the last headphones that I had ever got (instead of just the first lol), it wouldn't have been such a bad thing!

 
Hello. May I know how it change the sound? I did Kramer Mod on PortaPro and found the bass is a bit overwhelming so I applied another mod on it by removing centerdome part completely. Now the sound is hollow like. Not sure I like the sound. I like the sound less bass more treble to increase clarity. Does this mod helps? Any suggestion would be greatly appreciated. i am willing to purchase another 2nd hand unit if necessary to apply correct mod.

 

[bennyprofane]

If you want more clarity, I would go for the KSC75 (or SportaPro instead), the PortaPro has more bass and less clarity. And I wouldn't remove the center, a tiny 1 mm hole is okay, otherwise there is too much treble. PortaPro's are good for bass heavy music but I prefer my KSC75 much more and never use my PortaPros. You might be able to use the KSC75 drivers on the PortaPro headpiece, if you prefer that.
 
In my opinion, the metal mesh does not sound nice.

 

[Hutnicks]

  If you want more clarity, I would go for the KSC75 (or SportaPro instead), the PortaPro has more bass and less clarity. And I wouldn't remove the center, a tiny 1 mm hole is okay, otherwise there is too much treble. PortaPro's are good for bass heavy music but I prefer my KSC75 much more and never use my PortaPros. You might be able to use the KSC75 drivers on the PortaPro headpiece, if you prefer that.
 
In my opinion, the metal mesh does not sound nice.

The Sportapro uses the same driver as the Portapro (KSC 35)

 

[Kodiak567]

Not sure where to post it, but check this out:
 
After opening KSC75 and KSC35/PortaPro I found out that beside different diaphragm (KSC35 - cellulose, KSC75 with extra titanium) they do have slightly different grilles, as on picture. People reported sound differences but they also reported sound differences when Kramer-modded so I do wonder how much of it is simply related to different open spaces in grille. Moreover it seems that KSC75 grille is made out of bit better plastic and has a bit different 3d profile, but I doubt it affects sound quality - sharper edges can be seen with zoomed picture. [My KSC75 are from 2010 and KSC35 from 2016.]
 
https://i.imgur.com/0jPhu1k.jpg
 

 

[stuck limo]

  Quote:

Originally Posted by kramer5150 I have this unproven theory (specuation really) that treble and upper mids (frequencies with quick attack/decay transients) project from the center of the driver. While bass and "slower" frequencies tend to resonate more from the perimiter.

I tested this by taping a quarter to the center of each headphone and then listening to some music. The music ended up having less treble. The previous mod I did caused the treble to overpower the bass and mids a little. To remedy this, I made the outer holes bigger. Now, the bass is just as strong as it was before, but cleaner. The mids are better too.

These phones are awesome!

 
Are these still the recommended sizes and amount of holes? (13)?  I'm thinking of doing this mod tomorrow on my Koss Porta Pros.

 

[stuck limo]

  Did the Kramer mod to my PortaPros just a minute ago, difference is quite astonishing. 
 
Much better clarity and presence in the mids and trebles, and the bass has tightened up a little bit too - win win!
 
Looking to replace the pads next, been looking at Senn HD414 pads - anyone here tried them? 

 
Do you have any pics? I'm looking for ideas on how to do mine. I'm not a bass head (though I'd appreciate some nice, tight, round bass), I'd like more mids and slightly more highs for the details.

 

[stuck limo]

Ive been posting scattered comments about my KSC75 mods across several threads. I thought some of you might appreciate a more consolidated summary. Another forum member stated the idea is to "buy low... mod high". Thats basically all that this is. Hope some of you find this useful.


Carefully pull off the foam earpads. The little spikes can really tear the foam up, so pull gently and unhook them slowly from the little spikes. To unsnap the grille cover, use a screwdriver or knife and gently push... here.

The cover will pop off. Do not pry the cover up from the other side you run the risk of puncturing the diaphragm. I found this out the hard way and damaged a KSC50 driver. Notice that the grille is notched for proper orientation.

You can see Ive already begun to mod them.... Notice also that the earhook can easily unsnap if it is in your way.


Use a drill and knock some extra holes in the grille. The idea is to try and get as much unobstructed air between the diaphragm and your eardrum. Ideally you could just remove the grille, but that would bring on other complications (duh!).

Im using earpads from a koss KSC12. Its thicker foam than the OEM KSC75, so it places the drivers out away from your head a little. Gives more spatial distance and treble sparkle. Kind of like Grado bowls -VS- flats.

I use sharp hobby scissors and a socket and cut a hole in the middle of the foam. Again... maximizing un-obstructed sound from diaphragm to eardrum. IMHO the foam really masks the KSCs wonderful treble sparkle.

The result is a more open, dynamic sound. Mids jump out and treble really sparkles. Theres some intense treble in these little drivers, but its not intense in terms of amplitude... its more dynamic and ambient sounding. Its like a layer of glitter on top of some stellar mids. Theres some real frequency separation now that was not present before. Cymbal crashes are more separate from upper midrange guitars and keyboards. Kick drum bass seems to be more "airy"... has more depth to it, as opposed to a solid "thud". The "thud" is still there, but theres a sense of air around theat fundamental note.


Koss has a real winner here. Its my humble oppinion that EVERY head-fi member should own these or at least demo them and give them a shot. For $15... man... I cant think of a better bargain in the entire audio industry... guitar audio, car audio, home theater... you name it... the KSC75 is a real gem!! and a SUPERB value.


Hope some of you find this useful... remember "buy low - mod high"!!

Garrett

Can you or someone update this with pics and videos for the Porta Pros. I only find the KSC75 instructions and the Sportapros which seem to have different design.

 

[Feilong4]

Can you or someone update this with pics and videos for the Porta Pros. I only find the KSC75 instructions and the Sportapros which seem to have different design.

I found this video a while back with the Sporta Pro:
 

 
I got lost at some point, so I just dropped the project altogether because I messed up one side of the driver =/
 
EDIT: No idea how I got lost, I seem to got it now but too bad I still have ruined drivers.

 

[stuck limo]

I found this video a while back with the Sporta Pro:




I got lost at some point, so I just dropped the project altogether because I messed up one side of the driver =/

EDIT: No idea how I got lost, I seem to got it now but too bad I still have ruined drivers.

OK i found that but the view on how to get the diffuser out is very poorly done. I literally don't know how to attack the clips so they become unstuck and pop out.

Any ideas?

 

[Feilong4]

OK i found that but the view on how to get the diffuser out is very poorly done. I literally don't know how to attack the clips so they become unstuck and pop out.

Any ideas?

Yeah, I didn't get that as well. I ended up just snapping the thin plastic holding the clips. The grill still attaches on afterwards so it still works.

 

[stuck limo]

Yeah, I didn't get that as well. I ended up just snapping the thin plastic holding the clips. The grill still attaches on afterwards so it still works.

I broke mine too. There is only one clip. I got the diffuser out. Waiting now to drill. I can't believe no instructional video or tutorial/picures on the Porta Pros exists.

Are the Sporta Pros and Porta Pros the same driver? Are the mods going to accomplish the same on each of them?

 

[Feilong4]

I broke mine too. There is only one clip. I got the diffuser out. Waiting now to drill. I can't believe no instructional video or tutorial/picures on the Porta Pros exists.

Are the Sporta Pros and Porta Pros the same driver? Are the mods going to accomplish the same on each of them?

I think I read somewhere that they use the same drivers, but the Sporta Pros just tuned to be more bassy. Don't quote me on that though, it was a long time ago and my memory's hazy on that.
 
I think the mod does the same to both: Widens the soundstage and adds more treble clarity and bass impact if I'm correct. I didn't get to test a working modded Koss Sporta Pro/Porta Pro so I can't say for sure.