CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

Lobby => Headphone Measurements => Topic started by: Marvey on April 20, 2012, 05:58:53 PM

Title: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Marvey on April 20, 2012, 05:58:53 PM
Koss KSC75 Frequency Response and CSD Waterfall Plots
Tonally, these remind me of HF-2s a little bit.

(http://www.changstar.com/index.php?action=dlattach;topic=231.0;attach=863;image)

Lots of pounding high bass and a little strong in the upper mids. Sort of a poor man's HF2.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: ultrabike on April 20, 2012, 06:06:59 PM
I think this is very respectable for a $16 can!  8)
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: LFF on April 20, 2012, 06:09:40 PM
I think this is very respectable for a $16 can!  8)

I agree. Not too bad for the price at all.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on April 20, 2012, 06:15:08 PM
They look pretty darn fast and clean!  I prefer these to a lot of much more expensive headphones.  ultrabike, you're not alone on that one!  Though I haven't listened to mine in a while because the left side went out.  Koss warranty isn't really worth it for these things. 
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: omegakitty on April 20, 2012, 06:16:37 PM
They look pretty darn fast and clean!  I prefer these to a lot of much more expensive headphones.  ultrabike, you're not alone on that one!  Though I haven't listened to mine in a while because the left side went out.  Koss warranty isn't really worth it for these things.

My right side went out a couple of years ago. I tried to half ass it and reflow the solder where the cable entry goes into the earpiece to no avail. I liked them a lot as well.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on April 20, 2012, 06:23:10 PM
Mine were recabled with something schitty so that could be to blame.  I actually preferred the ksc-35 back in the day but they were prone to getting rattley after a while.  They were warmer though, I imagine they'd measure smoother and more neutral.  Would be interesting to see.  I'm suspicious that the titanium coating on the ksc-75 was done for durability, not SQ. 

I love using the ksc-75 for comparison on head-fi.  Always fun to say that I prefer them to a 1k flagship.  :-)
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: shipsupt on April 20, 2012, 08:00:09 PM
Don't they need the Karmer quarter mod??   ???
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on April 20, 2012, 10:03:02 PM
Don't they need the Karmer quarter mod??   ???

I think that takes them from HF2 to RS1.   :'(   

I'm actually surprised these measured this bright, I never thought of them as being particularly bright or bassy.  But it's been a while, as I said
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: Questhate on April 20, 2012, 10:08:03 PM
Yeah, the graph doesn't look bad for such an inexpensive headphone. How bad is that 5K peak?

Do these sound the same as PortaPros, or are they different? Always thought the PortaPros looked cool and retro -- but was surprised to see they cost twice as much as these KSC75s.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: omegakitty on April 20, 2012, 10:46:30 PM
The SportaPros have KSC-35 drivers in them. But they do not sound like KSC-35
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on April 20, 2012, 10:54:26 PM
What was your take on 75 vs 35 kitty?  That use to be a big debate on head-fi when the 35 was cheap and in production. 
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: omegakitty on April 21, 2012, 01:01:03 AM
What was your take on 75 vs 35 kitty?  That use to be a big debate on head-fi when the 35 was cheap and in production.

The 35 might have been smoother. Hard to say, it has been years since I heard either.

ultrabike- Koss website still sells the ksc-35 for $44.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on April 21, 2012, 01:18:38 AM
If they still sell the ksc35 then why do they send you 75's to replace broken 35's?
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: grev on April 21, 2012, 02:08:50 AM
ultrabike, at one time I had three sansa clips and three KSC-75s... :P  Although one set of them were intended to be parts of a christmas present to my girlfriend. haha

But yes, they sound great, I had the clip > ZO2 > ksc-75 in the chain and it's a very fun setup.  Also something about titanium drivers and lifetime warranty, isn't it?!
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: maverickronin on April 21, 2012, 05:26:39 AM
I love using the ksc-75 for comparison on head-fi.  Always fun to say that I prefer them to a 1k flagship.  :-)

I've done that kind of thing before too.  They compare very favorably to even the flagships that I actually like.

Also:

Audiophile General's Warning

Studies indicate that listening to the KSC-75 for long periods of time may cause intense regret, remorse, and disillusionment about the thousands of dollars you have invested in gear that only produce marginally better sound quality.  The Audiophile General recommends that such people only use the KSC-75 for listening to podcasts while shopping or doing chores around the house if they must own a KSC-75.  Failure to heed this warning may result in low self esteem, depression, and suicide.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: omegakitty on April 21, 2012, 01:38:33 PM
What was your take on 75 vs 35 kitty?  That use to be a big debate on head-fi when the 35 was cheap and in production.

The 35 might have been smoother. Hard to say, it has been years since I heard either.

ultrabike- Koss website still sells the ksc-35 for $44.


I don't know man, the KSC75 is $15 free shipping... Is it that much better?

EDIT: Also the clip doesn't look that comfy...

You're the one that brought up translanting 35 drivers into a 75 clip, that's why I mentioned Koss has new ones for only $4 more  ;)
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: ultrabike on April 21, 2012, 01:58:23 PM
Thanks man
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: RexAeterna on April 21, 2012, 07:21:29 PM

Audiophile General's Warning

Studies indicate that listening to the KSC-75 for long periods of time may cause intense regret, remorse, and disillusionment about the thousands of dollars you have invested in gear that only produce marginally better sound quality.  The Audiophile General recommends that such people only use the KSC-75 for listening to podcasts while shopping or doing chores around the house if they must own a KSC-75.  Failure to heed this warning may result in low self esteem, depression, and suicide.

naw, i would look at it in a brighter side of things. it just means i can sell all my stuff off and use it to pursue my dream as a professional porn star/man whore.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: grev on April 22, 2012, 01:06:14 AM
I think this deserves to be one of the pirates booty.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: thefoundMIDrange on May 08, 2012, 06:59:27 AM
Hi all. stumbled upon this effin great forum after a long self-education on the current state of the headphone 'industry' over at headfi.....enough about that for now....... The little koss is a real nice phone. Nice to see a thread dedicated to it. I had been enjoying it pleny in its stock form and recently started messing with modifying it in a DIY manner, kickstarted by stratocaster's advice and insight over at headfi suggesting that closing it in results in dramatic sound signature alteration. As much as I like the stock 75 in its little plastic shell, i have found that with a simple cable upgrade, proper matching with source and amp, and now, the idea of enclosing the litte titanium driver in a lightly damped wood cup, really puts this $20 miracle into a different league. Strato has a head start and has already modded his set to fairly high standards and I am in the process of doing the same but with a different pad setup. I will fill in some blanks when I get more time, but suffice it to say, closing in the 75 driver seems to act opposite of what happens when a grado or magnum driver is closed. No idea why...When the grado/magnum are closed, the sound goes tinny, thin and wrong. When closing in the 75, the sound gets fuller, bigger, more intimate, a touch more natural, and the already great low end starts to show even more potential. Bass guitars are very tuneful but kick drum still needs tuning. To wit; damping. I've just started messing with cotton, various materials for the end cap (means of closing in the back of the wood cups). Further dialing in will involve damping experiments on the inner surfaces (walls and back reflecting surface) and possible moderate side or back venting.

fyi, other phones i've owned and been more or less displeased with either immediately or with time:

grado hf2 (bass is a mess, but a decent phone with pretty accurate instrument reproduction)
senn650 (murky, incomplete, flat dynamics)
senn600 (same as above minus the murky)
grado rs1i (too airy, odd upper mids)
grado rs2i (odd upper mids - lacks punch/balls)
grado 325i (metalic bright- cool but quickly fatiguing)
grado 80i (hot distorted mess)
beyer dt880/250 (treble sounds like cotton candy, no mids)
Koss 950 stat (odd)
Fostex tp50 unmodded (wow this was a mess and needed to much work)
14 different sets of custom magnum driver sets in various wood cups and one set in stock metal (cool but for my record collection and tastes, couldn't dial out enough of the driver color. Always remained and made strings and snare drums sound a bit off but with just the right drivers (they vary) in the right cups, they could sound quite nice)
Grado ps500 (pretty nice, a bit too clean in the mids, uncomfortable due to weight, but other than the koss75, my favorite offering from the 'industry')


where i'm coming from. classic rock/jazz vinyl lover.

[urlhttp://www.youtube.com/watch?v=1A9mR6MOtXc&feature=related][/url]
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: Anaxilus. on May 08, 2012, 07:05:58 AM
Welcome!  Nice first post.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: Marvey on May 08, 2012, 07:07:58 AM
+25 karma points
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: thefoundMIDrange on May 08, 2012, 07:58:52 AM
25 sounds like alot but i'll take 'em..............I need all the karma pts I can get. I've done alotta wrong in my life.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: stratocaster on May 08, 2012, 09:26:21 AM
Just to let you know what I have been working on to give the ksc-75 a nice housing. I have given this baby the name stratoKOSSter. It is a closed can , and as lostMID has pointed out, has great potential. There is the possibility to try some venting as the hole in the middle can be pierced. But I have not found the necessity to do.
The cups are lined with Paxmate and filled with cotton to finetune the driver performance and reduce standing waves. All in all, this is just a fun sounding headphone, great balance, no Gradoesque 2kHz shout, yet forward sounding with nice bass backup and high end sparkle. I'm loving it.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: grev on May 08, 2012, 10:35:38 AM
I know of both stratocaste and theMIDrange from the grado/alessandro mod threads that I post over at HF, welcome, dudes!
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: Questhate on May 08, 2012, 11:22:36 PM
Yes, welcome aboard, MID and Strat!

Looking forward to reading about the results to your KSC modding. I know MID is gonna try every single wood in every single configuration with every single finish to get what he wants  ;D
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: ocswing on May 09, 2012, 12:06:31 AM
Just to let you know what I have been working on to give the ksc-75 a nice housing. I have given this baby the name stratoKOSSter. It is a closed can , and as lostMID has pointed out, has great potential. There is the possibility to try some venting as the hole in the middle can be pierced. But I have not found the necessity to do.
The cups are lined with Paxmate and filled with cotton to finetune the driver performance and reduce standing waves. All in all, this is just a fun sounding headphone, great balance, no Gradoesque 2kHz shout, yet forward sounding with nice bass backup and high end sparkle. I'm loving it.

That's pretty awesome. You should send it in to get measured!
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: thefoundMIDrange on May 09, 2012, 03:55:29 AM



strat is in austria so the logistics prohibit sending it to montana....I may send mine in at some point, I can't imagine that it would not measure nicely. Still dialing it in though, here's a shot in it's current state. totally closed with some light cotton inside and a type of rubberized paint sprayed on the walls. reverse bowl pads. What I'm finding is the pads (distance from the ear) and the inner treatment is tough to balance out. Also, when using stock bowl pads, the closed ends do not work nearly as well and things seem to get thin and tinny like grados do, but when using reverse bowls or just the stock koss pads, the driver is closer to the ear, bass comes way up and then it benefits from being totally enclosed. Then it's a matter of finding how to deal with the inside. There are some qualities I like when no damping or cotton is used but trying to balance everything out when I have zero knowledge about acoustics or headphone desingn is tough. But the pads really are key and dramatically change things. All in all I still like the stock headphone just fine. The modded set is an attempt to improve on the three slight shortcomings that I hear in the stock set, which are a little heavy and unrealistic on the trebles, a touch too airy through the mids at times, and a little too lean through the low mids. So far, the modded set has definitely moved all of those issues in the right direction and is a cool alternative to the stock sound
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: stratocaster on May 09, 2012, 01:22:32 PM
Try cheap pleather pads of the right diameter. You can find fitting ones from cheap headsets offered in computer stores or similar. That will dramatically change the sound. They are not perfect but give you an idea what nice leather pads could do.
I absolutely love the sound these produce with the L-cushs I lined with lambskin leather. You see the cushs in the pic.
Those pads are absolutely comfortable and truly magnificent sounding with the enclosed Koss.
 
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: thefoundMIDrange on May 10, 2012, 12:25:33 AM
maybe you could take a pic of the pad so I can see how thick the pad is. In other words, I'd like to come to know where the driver is when listening. Is it right on the ear or spaced off. I'd like to try and simulate what you have going on but without getting the driver right where you have it, I won't be able to hear what you have got. the slightest change in where the driver sits changes everything as you know. ......also, you seem to be suggesting that the material and perhaps the way the pad slopes away from the driver is affecting things? If so, A couple clear closeup pics would help here too..........
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: stratocaster on May 10, 2012, 04:50:26 AM
Can't take pics at the moment, since I am in London for a week and do not have the phones with me. But you see in the pic I provided above that the pad is just a normal Grado L-cush, covered with very thin lambskin leather. The driver is right where it is when you use your bowls.
Just use some socks or tights to give your bowls some 'pajamas' (http://www.head-fi.org/t/576717/grado-modders-go-magnum/1245 (http://www.head-fi.org/t/576717/grado-modders-go-magnum/1245), Post 1260). When you use thicker fabric, this brings the sound very close to what I am hearing with leather-covered bowls. Of course, if you use leather, isolation is a lot better and there is slightly more bass presence.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: thefoundMIDrange on May 19, 2012, 07:49:26 AM
I've been listening and comparing these to the grado ps500. With a recable and healthy burn in, these stock open 75's are my preference OVER the grado500. The sound signature is not too dissimilar actually, the grado's win slightly in the low and high end, but not by much, and the mids are nicer on the koss. more open and natural. the mids on the grado have a kind of boxiness to them. After spending thousands of dollars on headphones, these are my favorite, regardless of price. Couldn't be happier. I don't even feel they need to be amped, but burn in does help give these some body, as does a grado recable. I have an identical but fairly new set to compare to as well, that gives me the same feedback........ Plus, the koss has a quality to it that is hard to pin down, but quite enjoyable. Amazing phone.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: SanjiWatsuki on June 13, 2012, 07:20:52 AM
I was checking out the PortaPro frequency response curves at InnerFidelity and HeadRoom, and I noticed the sharp divot before the 5khz isn't in the frequency response. Do you think this means that the ringing isn't there in the PortaPro?
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: Marvey on June 13, 2012, 07:29:02 AM
Sharp notches in FR graphs sometimes turn into nasty ridges on CSDs.
Title: Re: Koss KSC-75 Frequency Response and CSD Waterfall Plots
Post by: spoony on June 14, 2012, 04:08:26 AM
I was checking out the PortaPro frequency response curves at InnerFidelity and HeadRoom, and I noticed the sharp divot before the 5khz isn't in the frequency response. Do you think this means that the ringing isn't there in the PortaPro?
It does show up in the CSD plot (http://en.goldenears.net/9862), albeit one of a seemingly shorter duration.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Marvey on June 15, 2012, 07:12:15 PM
As a public service, I'll make it more obvious:


(http://www.changstar.com/index.php?action=dlattach;topic=231.0;attach=1340;image)

Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: thefoundMIDrange on June 18, 2012, 12:21:28 AM
btw/fwiw. I've been comparing for awhile now a grado Ps500 with semi-stock ksc75(burned in/recabled) phones and prefer the koss. If I knew nothing of the price and auditioned each of the two phones, knew nothing about how cheap the koss looks or how more substantial the grado looked, and just went by sound and enjoyment of my record collection. No doubt the koss is preferred. It has a less boxy sound, more pleasant mids and a tasteful touch of compression (from recable in part) in the mids that is something alot of music lovers are looking for in audio reproduction. To me, a grado500 is a little 'dry' and grey in comparison. (and both phones I am comparing use the same cable -i recabled the koss with grado).........long live the mighty diminutive ksc75 ! 
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: SanjiWatsuki on June 20, 2012, 07:31:12 AM
I still love the KSC75s. Got a new one in today, because I had given a previous one away to a family member. Brought up the parametric equalizer and had some fun. Listening to the equalized KSC75s convinced me to put my Grado SR80is and Denon D2000s for sale on Craigslist. My Fostex had dethroned the D2000s a while back and the KSC75 just dethrones the SR series Grados for me, even after I equalized the Grados.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jerg on June 20, 2012, 07:24:06 PM
I bet the secret to its sound is its patented (?) titanium coating on the diaphragms.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on June 20, 2012, 07:45:58 PM
I don't think so because AFAIK the KSC-35 weren't titanium coated and they had all the same strengths and were more neutral (less treble energy)
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: SanjiWatsuki on June 22, 2012, 06:38:11 AM
Hey, purrin, if you still have the data, is there any chance that we could get a -36dB KSC75 waterfall CSD? I'm kind of curious how it holds up to the lower floor that you've standardized your measurements to.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Marvey on June 23, 2012, 08:21:28 PM
Here's -39db floor
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: SanjiWatsuki on June 23, 2012, 08:39:11 PM
Here's -39db floor

Thanks Purrin, you're the best.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jerg on June 28, 2012, 09:49:57 PM
These do cymbals like no other...even my HE400s can't match up against it in terms of cymbal fidelity.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: dBel84 on June 28, 2012, 10:13:53 PM
(http://cdn.head-fi.org/6/69/691dd53f_IMG_0238.jpeg)

The "Madonna" pioneer headphones on the extreme left are actually heavily modded KSC75 - I have been using them for many moons to test amp builds. Based on this thread, I suspect they measure as good as they sound. :)

..dB
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: donunus on July 25, 2012, 12:53:43 PM
After all this time I can't believe i still haven't bought a pair of these. I think I better buy a pair now since I need one for exercise anyways  :)p1
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: roBernd on July 25, 2012, 07:24:54 PM
(http://cdn.head-fi.org/6/69/691dd53f_IMG_0238.jpeg)

The "Madonna" pioneer headphones on the extreme left are actually heavily modded KSC75 - I have been using them for many moons to test amp builds. Based on this thread, I suspect they measure as good as they sound. :)

..dB

care to enlighten us what was done to the K501? WTF is wrong with the pads... or, what pads are these and how do they change the sound
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jerg on August 08, 2012, 02:54:32 PM
An interesting I observe with the stock KSC75's is that they sound thin, anemic, and lacking the bottom end thoroughly, if you use the earclips. With (any) headband mod and allowing them to press against the ears fills up the lower midrange and bass dramatically, makes it very tonally balanced.

Personally I have mine quarter-modded and clipped onto a PortaPro headband, it sounds insanely good, competes for headtime against my HE400s even.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: donunus on August 08, 2012, 05:25:29 PM
I used to also have some plantronics earpads that increased the bass and lower mids a good bit. I might get another pair of those to put on the ksc75 to make them sound bassier and fuller even when using the clip on.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jerg on August 08, 2012, 08:13:29 PM
I used to also have some plantronics earpads that increased the bass and lower mids a good bit. I might get another pair of those to put on the ksc75 to make them sound bassier and fuller even when using the clip on.

That's definitely a possibility. However I've gone through probably 6 pairs of different earpads trying to get these to sound best, and in the end the stock earpads with a quarter mod is still the best - the perfectly flat midrange is only preserved by them, any other earpad that increases the lower end muffles the sound considerably as a tradeoff. Having a headband mod, however, does not interfere with the mids, but also brings out the bass, so it's perfect IMO.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: donunus on August 08, 2012, 10:55:25 PM
By the way since it is the first time I bought the ksc75, my experience with these different pads are from trying them out with the portapro and the px100 so I am basically just assuming that those plantronics pads may come out neutral since they were super bassy with the headband based cans.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: rhythmdevils on August 08, 2012, 11:30:15 PM
I think those K501's have stock pads with tape around them.  Just a guess. 
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jerg on August 26, 2012, 12:43:58 AM
Went to a local head-fi meet today and for giggles showed a few people my KSC75s with headband mod. Wowed every single last one of them. For a second or two, these made them reconsider their decisions to drop all those Gs on the summit-fi stuff  :&.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: grev on August 26, 2012, 12:49:39 AM
Went to a local head-fi meet today and for giggles showed a few people my KSC75s with headband mod. Wowed every single last one of them. For a second or two, these made them reconsider their decisions to drop all those Gs on the summit-fi stuff  :&.
Isn't it also titanium coated and lifetime warranty?!?!?!??!
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jerg on August 26, 2012, 12:53:27 AM
Went to a local head-fi meet today and for giggles showed a few people my KSC75s with headband mod. Wowed every single last one of them. For a second or two, these made them reconsider their decisions to drop all those Gs on the summit-fi stuff  :&.
Isn't it also titanium coated and lifetime warranty?!?!?!??!
Yep. Although the lifetime warranty doesn't cover shipping costs for shipping the defective pair back to Koss.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: ultrabike on May 01, 2013, 07:17:42 AM
Might as well share these...

The last one overlays the FR of another set I have.

Seems pretty well matched. I really like these for the price and for exercise. They are fun, but not DT990 fun. Gradoesque sound at a fraction of the price.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: XRG1 on May 16, 2013, 05:20:35 AM
Might as well share these...

The last one overlays the FR of another set I have.

Seems pretty well matched. I really like these for the price and for exercise. They are fun, but not DT990 fun. Gradoesque sound at a fraction of the price.

Gawd how I love these phones havent been without Porta sporta or 75's since they all existed. Now vying for eartime with phillips earclips with the obligatory headband mod (bliss I tell ya!)
Looking at these graphs though I cannot help but think of Vid's posts in on FanboiFi in the ortho thread about convolution software to equalize the channels and smooth things out. If anyone can get that happening, it might drop a few more jaws at the next meet:)

I love the snubs when I recommend the Koss in the what should I buy threads over there. People could be using the worst stuff in the world and the pseudo staffers always come back with an exotic recomendation.

Dad what should I buy for my first car? Gee kid get in with the cool people and buy yourself a McLaren, you can learn about driving later.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jupitreas on May 17, 2013, 12:01:46 PM
Here is a mod I did of the very poor KOSS PRO4AAAT. It really sounded dreadful stock, so I went ahead and removed the original drivers altogether and transplanted some KOSS UR40 drivers into the enclosures. As far as I know, the UR40 uses the exact same titanium drivers as the KSC75. Furthermore, I added some real leather padding to the headband that I scavenged from one of the broken vintage headphones that I had in the attic and attached some eBay Superlux HD668B velour pads instead of the terrible vinyl pads that came stock with this headphone. I used the UR40 drivers with this headphone for a while but then, when I got one of those Anniversary Edition PortaPros, I used those drivers instead as they are a bit darker and lack that titanium metallic tonality that the UR40 seems to have. The end result has really nice soundstage and great bass, although there is some ringing that I can detect in the upper mids. I think I'll solve this by adding some additional damping to the inside of the enclosure, as it is a semi-open design.

(http://aheadstudio.net/stuff/headphones/koss-mod/1.jpg)
(http://aheadstudio.net/stuff/headphones/koss-mod/2.jpg)
(http://aheadstudio.net/stuff/headphones/koss-mod/3.jpg)
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: jerg on September 12, 2013, 01:55:56 PM
GoddAMN this sounds great with Kramer mod, headband (so they clamp flush to the ears), and YUIN earpads. Everytime I'm using it, it challenges my bigger headphones. Music just sounds so right out of these.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Deep Funk on June 28, 2014, 11:04:12 AM
I just ordered the KSC75.

If the first pair is good enough to wow me I will buy a second pair. They are 30 Euros in the Netherlands.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: ultrabike on June 28, 2014, 07:31:49 PM
Mmmm, that is a bit expensive. Not sure if they will wow, but they r reasonable IMO. Sort of Grado like, but for less $$$. They are not necessarily the last word in fashion or build quality though.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Deep Funk on June 28, 2014, 09:10:57 PM
Compared to U.S. Dollars, yes. For a Dutchie like me, as long as the EU-zone is stable the Euro will remain a strong coin.

Sound is a first priority. When I am genuinely impressed I intend to buy the second pair for modifications. When changing the cushions and closing in the driver are as effective as earlier described, I must have a go at it.



Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Claritas on June 29, 2014, 12:12:29 AM
I recommend the headband mod. Otherwise, the cables will cut out prematurely from being man-handled.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Solderdude on June 29, 2014, 06:49:29 AM
One of my KSC75 (also have KC35 and KSC50) measures like this:

(http://diyaudioheaven.files.wordpress.com/2014/01/ksc75-stock.png?w=921&h=567)

They don't 'wow' me, certainly not when comparing them directly to better headphones.
I recommend to just use them and NOT do comparos with them (unless you compare them with crappy headphones).

With this I mean they sound excellent when listening to them and do not seem to have anything 'missing' or obviously flawed in the sound.
It is very easy to get 'tuned' into the music and thus they sound very convincing and real.

Of course it has some flaws (lacks extension to both ends but extends far enough to not be obvious), but strangely enough they only show their 'flaws' when comparing them to better headphones directly.

Funny thing is... if you put them on the next day you won't hear the flaws any more and they sound just fine again.
They are excellent for on the go, but useless on a bike (wind makes lots of noise) and a bit fiddly to put on until you get the hang of it.
You may have to bend the earclips to get an equal seal/sound or more comfort.

It's one of those headphones that I have always kept around and will buy again if they ever fail.
To me they are certainly worth € 30.- ($ 45.-) but paid less for them (fleabay)

I did a lot of measurements on its siblings (KSC35/PortaPro) and mods (coin mod, Kramer mod, thicker pads)
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Deep Funk on June 30, 2014, 10:32:39 AM
The Koss KSC75 just arrived. I immediately unpacked the headphones, inspected them and turned on the CD-player.

I use an old Sony CDP-750 and the Koss is connected via the headphone out with bigger jack plug. Liquid Soul's album "Love In Stereo" is playing and well, I am wowed. The Psy Trance sounds detailed, even and the bass grooves sound groovilicious. 

If this was my first headphone, I would never have gone through some headphones I tried through the years. Out of the box the Koss equals my K181 and approaches the sound of my K500. The KSC75 driver kicks more ass than some expensive headphones I have auditioned through the years, that includes the fun HF2 and the stock HD800.

This Koss does what the HD250 II Linear did for me. It sounds transparent, fun and balanced enough to just forget about all my other headphones. It is not K500 transparent though.

I am buying a second pair and yes a headband modification is necessary. A semi-closed configuration can turn this humble Koss into a Kossinator that outkosses more expensive headphones. 

P.S. I am usually more reserved. I am honestly surprised by the audio goodness the KSC75 brings.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: spoony on June 30, 2014, 03:06:09 PM
My modded PortaPro (Kramer mod, KSC75 pads) sounds clearer than either my headband modded KSC75, or a stock PortaPro (compared via 3-way splitter cable). Just FYI ;)

Enjoy these little gems.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Deep Funk on June 30, 2014, 05:09:19 PM
I have been reading about modifications for the past hour  p;)

The KSC75 stock does so many things right that I can only enjoy the music. That is all I need in a headphone, generally speaking.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Claritas on June 30, 2014, 07:46:57 PM
It sounds even better amped. (Listening to it amped is what finally persuaded me to try Grados for organ works.)
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Deep Funk on June 30, 2014, 09:14:39 PM
Second pair ordered. The last time I found it difficult to take off the headphones it was with the K500 and the HD250 II Linear.

This small headphone is too good to ignore.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: ultrabike on June 30, 2014, 09:51:11 PM
LOL! I got three. Wife likes it too. Great for music and movies...
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: M3NTAL on July 01, 2014, 05:39:39 AM
Lets see some photographs of C* member interpretations of the "Kramer Mod". It has been a while since I have modified KSC75 grills.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Solderdude on July 01, 2014, 10:20:37 AM
(http://diyaudioheaven.files.wordpress.com/2014/01/dscn2608.jpg)

below: stock KSC75, Kramer modded which means the holes as above + thicker pads.
Without thicker pads  you get relatively more treble.

(http://diyaudioheaven.files.wordpress.com/2014/01/ksc-stock-vs-kramer-mod-thicker-pad.png?w=614&h=456)

The coin mod (cutting out the middle part of the foam) will also increase the treble.
Not because the foam blocks the higher frequencies (which it doesn't it is acoustically transparent) but because the pads compress somewhat more and this moves the driver closer to the ear.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Deep Funk on July 01, 2014, 01:50:52 PM
The second pair arrived. In my impatience I already cut open the ear cushions of my first set.

A 1 inch circular hole in the ear cushion is the best solution for me. The hole makes the KSC75 have more bass impact, more midrange and more overall detail. My KSC is slightly bright but at lower volumes it beats the Philips and DT250-250 for me.

If I had a shed and the tools I would have done the Kramer modification already.

Thanks for the recommendations, information and measurements.  p:3 KSC75
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Mullet on December 12, 2014, 04:58:27 AM
I love the KSC75s. I use mine in the gym. I used to wear in-ears at the gym and ruined a few pairs by getting sweat in 'em. This pair I've been rockin' for about 3 or 4 years and they're still going strong. I could give a rats ass if they make me look like a d00fus while working out.  :)p3
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: speakerphone on June 21, 2015, 06:12:59 AM
(http://lh3.googleusercontent.com/-Uv4FzjsV_ms/VWiobTKRSEI/AAAAAAAAAsI/YwQdkdkMGgQ/s1600/KSC75Raw.png)

Raw


(http://lh3.googleusercontent.com/-Z1ezHDt0k1Y/VWiobrz3xQI/AAAAAAAAAsQ/hPCnCfwM2oU/s1600/KSC75DF.png)

Diffuse Field Target Compensated


(http://lh3.googleusercontent.com/-b1ONBDHF9jk/VWiocIWBIzI/AAAAAAAAAsY/87eKhek7OUI/s1600/KSC75OW.png)

Olive-Welti Target compensated


(http://lh3.googleusercontent.com/-5H66AAQ4w1g/VWioco5ltSI/AAAAAAAAAsg/NsZh8TSQ95M/s1600/KSC75CSDR.png)

CSD - R


(http://lh3.googleusercontent.com/-Fl9H6jewHMk/VWiodOARvHI/AAAAAAAAAss/VOE8hYkIPr8/s1600/KSC75CSDL.png)

CSD - L


(http://lh3.googleusercontent.com/-gc9P5UKDzbk/VWiodqOTvGI/AAAAAAAAAsw/3Q681OB121A/s1600/KSC75THDL.png)

Harmonic Distortions - L


(http://lh3.googleusercontent.com/-_kalBlSgBJI/VWioeBg2AkI/AAAAAAAAAs4/QD62i7G-xYs/s1600/KSC75THDR.png)

Harmonic Distortions - R


(http://lh3.googleusercontent.com/-P2Da_xEVMBQ/VWioe4aiANI/AAAAAAAAAtE/Bv4Ns-jQ8gY/s1600/KSC75IP.png)

Impedance Magnitude


Here is Koss KSC75 measurement data from my rig, my apparatus is:
Occluded Ear Simulator: complying with IEC 60318-4 (former IEC 60711), Pinna Simulator(Small ear 35 shore-OO) complying with IEC 60268-7 annex A, and dimensionally complying with IEC 60318-7 (former IEC 60959)

Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Solderdude on June 21, 2015, 07:11:51 AM
Nice set of measurements ! :)p1
The diffuse field looks about 'right' to me.
The OW does not seem to jive with what I am hearing, in this case.
It suggests a bass-less (steep drop off below 100Hz) headphone with piercing (+10dB) treble.
To me they sound very mildly U shaped and only lack some sub-bass (and upper treble) extension.

Can you post your sonic impressions as well (how they sound too you ?).
CS is all about linking measurements with what we hear, not just plots.





Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: speakerphone on June 21, 2015, 07:25:11 AM

Can you post your sonic impressions as well (how they sound too you ?).
CS is all about linking measurements with what we hear, not just plots.


Ah, I see. I heard this that it is lack of frequency extention above 12~3kHz. And low-mid bass is boosted little bit, and vocal is pretty good with this headphone.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: playboiiz on August 17, 2015, 08:29:50 AM
Does this headphone scale with better amp/dac?
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Solderdude on August 17, 2015, 09:01:57 AM
To me it doesn't scale (much).
Sounds about the same from a DAP as when fed through an amp.
Others may have different experiences though.

A downside for me is that it does not really play well any more at higher than 'normal' SPL.
Experienced the same with K500 etc.

Still goes loud enough for me.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: spoony on August 17, 2015, 03:41:01 PM
Does this headphone scale with better amp/dac?
I think it sounds a bit more dynamic and clear from my GO450 than the Clip+.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: Claritas on August 17, 2015, 11:49:12 PM
Does this headphone scale with better amp/dac?

Everything sounds better to me amped, even this. Sometimes I wish I could unknow that.
Title: Re: Koss KSC75 Frequency Response and CSD Waterfall Plots
Post by: takato14 on August 19, 2015, 03:22:51 AM
Everything sounds better to me amped, even this. Sometimes I wish I could unknow that.
I have never heard a headphone that didn't improve with more power. Except maybe the HD700.