Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › Kramer-mod... KSC75...
New Posts  All Forums:Forum Nav:

Kramer-mod... KSC75... - Page 22

post #316 of 505
I tried the Kramer Mod and I must have done something wrong, because the diaphragm kept rubbing against the grille - causing rattling. I tried without the grille and the diaphragm kept rubbing against the ear foam pad - causing rattling; even after I cut the middle part of the ear foam pad out. So I decided to modify the Kramer Mod a bit. I decided to forgo the grille entirely and used a pair of lady's lingerie. I discovered in the process that without the ear foam pad the lack of seal from the ear foam pad reduced the bass impact.
Anyway I have to be extra careful with the headphone because the diaphragm is only protected by a pair of lady's lingerie.
LL
LL
LL
post #317 of 505
Quote:
Originally Posted by accurate_dB View Post
Anyway I have to be extra careful with the headphone because the diaphragm is only protected by a pair of lady's lingerie.
LOL!
post #318 of 505
Modded my SB49s (bought before learning of head-fi) and the result is quite good. They're still not amazing headphones, but at least they're usable.
post #319 of 505
just did this. Can tell a small difference, although it might be placebo. I got some scratches on the diaphragm also. And even accidentally got a piece of metal stuck to the magnet..... gave me quite the scare.

And I took off the clip and confused which phone is right and which is left. Does it matter any?
post #320 of 505
Not unless you want them to be consistent.
post #321 of 505
Quote:
Originally Posted by accurate_dB View Post
I tried the Kramer Mod and I must have done something wrong, because the diaphragm kept rubbing against the grille - causing rattling.
When I did the Kramer mod, I found two things you might want to consider/try. First, the convex diaphragm can "invert", causing the curvature to flatten and hit the grill. I put the back of the earpiece to my lips and inhaled through the airholes/vents. The diaphragm popped back to its proper shape.

Second, when I was drilling the holes in the grill (I used a run-of-the-mill power drill), there were tons of burrs left on the backside of the grill that I had to scrape away using a razor and file.
post #322 of 505
I did the mod just now, but apprently I put couple of small dents on the diaphragm. IT seems to have no effect on sound as it sounds better (after the mod, dent seemed to not affect the sound). Oh well, I can always send it back...and I do have a spare pair.
post #323 of 505
I may not do this mod at all, since I have superb high end hearing (even at an advanced age) and many posts indicate this INCREASES the treble which is already more than sufficient. Word is that many in the population have hearing damage from too loud music playing and thus some may need a high end boost.

I can hear a small battery powered wall clock ticking two rooms away. (A curse , not a blessing)


These sound much better when used in a headphone enclosure (I used some old sennies, px-200). The hang off the ear style does not give you enough pressure on the ear, you lose bass and treble


PS After some quick A/B testing , I did do the quarter mod, it seems to open up the soundfield a bit.
post #324 of 505
Quote:
Originally Posted by jdop2 View Post
I may not do this mod at all, since I have superb high end hearing (even at an advanced age) and many posts indicate this INCREASES the treble which is already more than sufficient. Word is that many in the population have hearing damage from too loud music playing and thus some may need a high end boost.

I can hear a small battery powered wall clock ticking two rooms away. (A curse , not a blessing)


These sound much better when used in a headphone enclosure (I used some old sennies, px-200). The hang off the ear style does not give you enough pressure on the ear, you lose bass and treble


PS After some quick A/B testing , I did do the quarter mod, it seems to open up the soundfield a bit.
i did it to open up the mids which i felt were very recessed. I did all the drilling except the one in the center. i too find the treble already enough.
post #325 of 505
Looks like Koss changed the mini-plug. The design is similar to the plug on the Apple earbuds. Perfect those small headphone ports. Only thing that has me a little concerned is the lack of strain relief.

Sold and purchased through Amazon.com (not from one of the Marketplace sellers). No mention of the revised mini-plug.

post #326 of 505
for the record, I did a canare 4e5c cable job and it seriously opened up the bass and filled out the mids. seriously.

I had a volume adjuster on mine, though, so that would probably be it.
post #327 of 505
Does anyone know how to remove the volume pod and add a resistor in there? 75ohm seems to be a recommended value.
post #328 of 505
Two dump questions for the readers of this thread (if there is still).

#1
When recabling the KSC-75 should I remove the older solder or using the original one will be fine?

#2
I am using 26 AWG SPC. Is Techflex enough to avoid microphonnic cable, or sould I insert the cable into a yaw before installing the techflex? (at least between the connector and the "Y" where the cable are splitting)

Thx
post #329 of 505

Kramer Mod- My interpretation (long, pics)

I must start this post with a sincere acknowledgment to Kramer. If not for his bold and creative mod, I would not be enjoying my KSC -75s as much as I am now. Thanks very much for pioneering this work, Kramer! And a big thanks to all who contributed to the thread. I have learned quite a bit from many comments and ideas here. And props to tstarn06 for convincing me to give it a go.

I approached my version of the Kramer mod with a few thoughts. I did not want to drill out the center hole for fear that this would add even more treble to a slightly bright overall sound signature. I also wanted to keep the foam intact for now to protect the drivers and to see if it really needed more opening up upon after mod audition. And I wanted to do something to keep the bass sounds focused.

With those thoughts in mid I set out to do the Kramer mod. I used a fellow members guidelines for size of holes starting with four 1/8 in holes around the perimeter and then four 5/32 in holes around the next inner most circle. The 1/8 in holes drilled fine with my regular Black and Decker variable speed drill, but the 5/32 holes did not. They must be drilled with a much slower speed and with a slight angle tipping the drill slightly away from the slanted material and into the side of the surface a bit. If you go directly in vertical and with high speed you may experience some bit slip and then have the entire grill end up twirling up your bit. That caused a problem with extra material being lost instead of a nice hole.

After cleaning up any jagged bits with a razor blade cutting knife, I was on to creating a foam surround donut for the perimeter of the gray housing. I installed the grills back on to the housing and prepped the surround. I used foam Light Switch Sealers that I picked up from Lowes for $1.47 a pack. There are 8 in there and you can get 2 surrounds out of one piece. I chose this because it is fairly dense foam and because it has a lower profile so it will not stretch the foam pads significantly and because it would probably focus the bass a bit more than a more open foam.

I first tried tracing a pattern on paper to use with the foam as a template. Not so good, so I went right to cutting the foam by scoring a line around the housing, being careful to not cut the cord. I thin cut all the way through with the razor knife. Then I took off the grill and pushed it firmly into the foam to make marks. I cut out the center along those marks. I replaced the grill and got ready to mount the surrounds. I am not a good craftsman and my close work is sloppy but I got it done. I used Elmer’s Craft Bond tacky glue which promises to remain flexible should I want to reverse the surround mod, by cutting through it some day. I applied a thin bead around the solid perimeter of the gray housing and carefully positioned the foam on the housing face. I let it dry and then reattached the foam pads. I did not do the Quarter mod to the foam because I wanted to see how the mids improved and how prominent the treble was first.

Upon listening with my Toshiba T-400 later that night, I was very impressed with the results. First the treble was not in your face. It is balanced and smoother with perhaps a bit less air but with a similar sound signature as before. Not as breathy is what I perceive, but that could have more to do with what happened to the mids. The mids are way better. Better definition,, clarity, a bit more immediate and so nicely integrated with the treble that I think they were almost as good as my memories of the AKG K271s. The dynamics of the mid presentation are also much better. The mids just get transformed with this mod.

As for the bass, it has become more easy to hear but not much more defined. It still has limited extension but it has become a bit more focused. It blends nicely with the mids and has not become too bassy. This area is still a bit weak for the KSC -75b, I’m afraid. But overall the mod has elevated the sound to a smooth and fun level. I can think of half a dozen over $50-$150 cans that I would replace with these.

The foam surround have an added benefit of applying more pressure to the ear and coupling the phones more tightly to your ear. While this helps the bass focus, it feels like someone is pinching the ear. It hurts a bit at first but then you get used to it or  numb. Have since bent the silver piece outward to relieve the tightness.

A quick note on sources. With the Toshiba, differences between stock and mod are really easy to hear using WMA lossless. With my Creative Zen V Plus the differences are also audible but you really do not hear what the mod can do without a top notch source. I must say the Toshiba trounces the Zen V Plus for sound quality. Now I can see why some folks have commented that some mods are slight if nothing else. Sources matter.

My next steps are to try the quarter mod, but I do not think I will go with a recable. I need to use these when on the treadmill and the weight and flexibility of the cord matter to me. If anyone has any thoughts about the quarter mod and it’s affect alone on the sound of the Kramer mod, I would like to hear those.

I hope this will be helpful to those who have not tried the Kramer mod yet, and inspiring for other great mod ideas to come.
LL
LL
LL
LL
LL
post #330 of 505
So, you drilled 8 holes in the plastic cover of each driver (Kramer mod variation), glued a thin circular piece of foam to the plastic cover, and you prefer the results. Excellent!

I tried something similar to this before cutting any holes. I cut the circles of foam from $1 insoles. The insole foam looks about twice as thick as the foam you used, but the results I got were unfavorable. IIRC the sound stage collapsed and the high frequencies were messed up. I use the KSC75 with a cmedia xtremesound card. I'm now enjoying a modded KSC75 with modded HD414 pads.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphones (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › Kramer-mod... KSC75...