[waynes world]

  I totally removed grills from my Koss UR40 (same drivers as KSC75), now the only thing between the driver and my ears is thin felt. And sound has changed significally, it's finally opened up! In stock they really bored me with sibilance and harsh treble, now this problem is partially solved. But i don't recommend to remove the foam from back side - it makes the sound too tinny.

 
Those drivers can be damaged easily. You may want to do something like this to protect them:
 

 

[Incipit]

So, I decided to go further, and take off foam from back sides, then place it inside the earcup right behind the unprotected driver (with no stock grill on it). Now they're not over ear, but on ear. Also i take that cheap and sticky surface from cushions - now they felt like velour, very comfortable! They finally sound better now, and everyone who have UR40 can do this mod for free.

 

[ULUL]

This is an old thread but I just found this today. 
 
Finally cracked open a brand new pair of KSC 75 I've had lying around for years in the package. Wow, impressed for $15. Should have tried them years ago. Don't even remember when I purchased them.
 
Anyways, stumbled on this thread. 
 
Question.  I see that the Kramer mod  includes drilling holes in the driver protector. 
 
Anywone simply just rip out the protector itself and then leave it bar, and just use the Sennheiser PX200 ear covers?  Should be enough to protect it.  I'd think this this takes the kramer drilling mod to its logical conclusion - removing the entire protector, and then just add a ear cover that provides some distance from the driver. 
 
Anyways, anyone try this and can report the results? 
 
Thanks,
ULUL

 

[waynes world]

  This is an old thread but I just found this today. 
 
Finally cracked open a brand new pair of KSC 75 I've had lying around for years in the package. Wow, impressed for $15. Should have tried them years ago. Don't even remember when I purchased them.
 
Anyways, stumbled on this thread. 
 
Question.  I see that the Kramer mod  includes drilling holes in the driver protector. 
 
Anywone simply just rip out the protector itself and then leave it bar, and just use the Sennheiser PX200 ear covers?  Should be enough to protect it.  I'd think this this takes the kramer drilling mod to its logical conclusion - removing the entire protector, and then just add a ear cover that provides some distance from the driver. 
 
Anyways, anyone try this and can report the results? 
 
Thanks,
ULUL

 
As per my post just a few above, I put a metal grille over the driver, which I think is an option similar to what you are suggesting:
http://www.head-fi.org/t/124243/kramer-mod-ksc75/510#post_11088497

 

[bennyprofane]

Stumbled upon the world of Koss moding yesterday and am excited to try this.
 
In this video - https://www.youtube.com/watch?v=XMFGuNa2WEM - the user trindysmom recommends only drilling four holes 
compared to the original Kramer mod whereas Charles Altmann recommends 17 holes: http://www.tera-player.com/TERA_pics/koss_17_holes.jpg
 
I'm wondering if any other people have tried different configurations and could share their experience.
 
trindysmom explains in his video that he has tried a multitude of variations and that too much ist not good. This also stands in contrast to the people who say it's best to remove the
grill altogether and replace it with mesh, no?
 
There are many options and I would really love to learn more. I am  getting the KSC75 as well as the PortaPro and want to make some comparisons once they are modded.
I am also thinking about replacing the cable as they tend to brake anyway and this would also be another way to improve the sound.
 
I am searching for tutorials for making a high quality cable and trying to figure out if I'm technically fit enough to do it, as I'm not that experienced.
Otherwise I might go for something like this: http://forzaaudioworks.com/en/product.php?id_product=45
 
I also read in a German forum that some people made their grill holes with punch pliers like these: http://goo.gl/0jEH7a Anybody have any experience with this?
 
Any help, tips, opinions or links are very appreciated. Thanks so much to Kramer and all the people who have contributed here.
Also, if Kramer reads this, perhaps you could relink the pictures on the first page of this thread. Thanks!

 

[bennyprofane]

So, I tried the Kramer Mod with the punch pliers and it works. It's not the ideal solution as it puts some strain on the plastic but it doesn't break it.
I made a small video of the process: 
 
https://youtu.be/WuKO006dhoc
 
So far I have only made four holes as trinysmom suggested, thinking about doing more...
 
Still hoping to hear if anybody has compared 4 holes vs all of them.
 
Edit: I wanted more bass so I added some holes. You have to be careful with the punch pliers as you can bend and crack the grill but they sound great now compared to earlier. I'm thinking it has enough treble so I haven't put a hole in the middle.
 
Here is a picture: http://i.imgur.com/OBk4XEK.jpg

 

[bennyprofane]

Last update, after adding the outer circle holes, I now also punched in the middle hole. So, the punch pliers can do the entire Kramer Mod fast, easy and dirty. The sound is amazing, now. I would say the last hole in the middle brought another huge change and the overall sound has the biggest wow factor so far, it's very 3 dimensional, clear, it really pops out in your ear. The different elements in a song are very discernible and take up a lot of room, very impressive. The only downside is what I had already feared, the treble is almost too high now, it sounds great but I can imagine it also possibly bringing higher strain to my ear. Just listened to Johny Cash's "Solitary Man" and the high guitar chords almost tickle in my ear. I might order another one and do some further testing.

 

[bennyprofane]

Now I did all the holes with the punch pliers. There are a few cracks in the grill (as you can see) but it works and sounds great. As experiment, I've put some scotch tape on the middle hole (to reduce treble) and made a hole with a needle in the middle (to increase it a bit but not too much). So far it seems to be working and sounds really good.
 
Here is a pic: 
 
http://imgur.com/xQOs6to
 
 
btw, those looking for a compatible headband in Germany (or Europe): http://www.amazon.de/gp/product/B00XL318HW
 
You have to order ten for 12 € but they work well and and they're probably better than the Parts Express ones, as they don't change their size so easy.

 

[Feilong4]

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?

 

[Tulon]

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

 

[Feilong4]

  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

This isn't a question on how it sounds itself, but what if one of the drivers seems to be producing less bass/volume than the other?
 
Is there a (cheap) fix?
 
I didn't seem to touch the drivers at all so I have no idea why this is. Barely touched the cable either.

 

[Tulon]

  This isn't a question on how it sounds itself, but what if one of the drivers seems to be producing less bass/volume than the other?
 
Is there a (cheap) fix?
 
I didn't seem to touch the drivers at all so I have no idea why this is. Barely touched the cable either.

 
I guess you could re-wire them?  Or maybe they just failed in some way?  I think Koss offers a lifetime warranty though, so if you can take advantage of that I would probably go that route.  I believe they will replace it for free, you just have to pay shipping.

 

[Wisor]

Hey,
 
I bought Sennheiser px200 pads for my koss KSC75. At the moment my headphones are stock and aren't modded.
 
I wanted to ask here before I do any mods if kramer mod improves the treble?

 

[Wisor]

Hey,
 
I put Sennheiser PX200 Pads (541341) on my KSC 75, and I must say that is one of the biggest mistakes you can do with this headphones.
 
 
Many people in this topic said it's an UPDATE, well its not. Sennheiser pads cover outer holes on the plastic housing.
 
The result is muddy,muddy and again muddy sound with absolutly no treble.
 
It's true, they add a bit of isolation and the are much more comfortable to wear, but sound getting out of speaker is trash.
 

So if you are an owner of KSC75, rather use 5$ on a glass of beer than on a sennheiser pads.
 
 
EDIT:
 
I don't know how they sound with krammer mod. I am going to try it in few days.

 

[Headzone]

hmm .. I had cut the plastic grill in half on my Portapros. Result is much more natural sound with better dynamics and imaging. They are still crap, but at least they are now listenable. Drums sound tighter and punchier, bass has slightly less overhang. If you plan to mod them AT LEAST remove the mid-piece from the plastic grille. No need for a drill.