CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => Headphone Measurements => Topic started by: Marvey on July 10, 2012, 01:33:16 AM
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Koss KSC-35 Frequency Response and CSD Waterfall Plot Measurements
(http://www.changstar.com/index.php?action=dlattach;topic=393.0;attach=1742;image)
These sound like refined KSC-75s. Still bright. Got a "detail" thing going on. Very smooth though. They remind me of Magnums. Lots of mid-bass, helps balance the treble.
CSDs ridges are cleaner than the KSC-75.
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Koss KSC-35 Harmonic Distortion Measurements
- Heehee. High bass distortion. What did ya expect for such a tiny driver?
- Past the bass, very low overall 2nd order (and hence THD). Once of the advantages of close distance to the ear. Driver doesn't need to work as hard.
As usual, measurements taken with headphone calibrated to 90db SPL A-weighted from an Objective 2 amp.
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reserved
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alright, go koss! it's also pretty cool how from 5k and up the fr and csd shape matches up so perfectly.
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Wow. That's a lot cleaner than I expected. I didn't think there'd be much of a difference.
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Similar FR, but the 35s sound really clean and refined. Gonna take distortion measurements for KSC-75 next to compare. Note that I just posted HD measurements for these up above: http://www.changstar.com/index.php/topic,393.msg6522.html#msg6522 (http://www.changstar.com/index.php/topic,393.msg6522.html#msg6522)
Compare to KSC75s which have more distortion: http://www.changstar.com/index.php/topic,231.msg2732.html#msg2732 (http://www.changstar.com/index.php/topic,231.msg2732.html#msg2732)
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Any chance you check StratoKOSSter distortion?
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Without the 5k peak / ringing (or even just with less of it) these would be close to perfect. Of course the bass is never optimal with small drivers like this but this midrange at least on charts seems to be the best of the best.
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Any chance you check StratoKOSSter distortion?
Don't know what's causing that spike. It could be because of the loose mounting of the drivers.
Compared to the stock KSC-75, 2nd order seems to be a tad higher, and 3-5th order seem to be a little lower.
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Marv, thanks for providing HD distortion measurements for the Stratos. As for the spikes, IMHO it might not be the fact that the drivers are mounted loosely, but resulting from the drivers residing in a closed shell and thus the problem might be backwave related.
The spikes correlate to the dip in the FR around 4K. There is this dip between 3.5 and 4.5 KHz with both stock 35 and 75 drivers. The dip in the Stratos is just more pronounced, but it is still the same dip. My guess is that the spikes might be caused by reflections in the cup hitting the plastic driver back.
So, what I did was to cut out a ring of thin felt I used to dampen my Yamahas and cover the driver back with it, thus resting between driver back and foam damping. To my ears, running the Stratos through SineGen, the improvement is noticeable.
Seeing that you must have loads of time to try out mods, with absolutely no measurements taking your time at the moment, you would certainly not find the time to try this out on your Stratos? On the other hand, I am sure you might earn yourself half a Karma point by doing so!
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Does the KSC35 have the same front plate as the KSC75s? I'm contemplating getting a pair of these and just swapping my kramer-modded koss front plate onto the 35's.
Also, rumours on the internet say Sportapro has the same driver as KSC35s, is that true?
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The treble region... reminds me of....
(http://www4.images.coolspotters.com/photos/371837/nicole-scherzinger-and-sign-of-the-horns-hand-gesture-gallery.jpg)
headbang headbang headbang headbang
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I was chatting to the KOSS folk at RMAF and they were telling me that KSC35, KSC75 and sportapro all use the same driver - no idea if this is true but this is what they said..dB
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I'm impressed. I can live with a bit of brightness and extra mid-bass. Want...
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I was chatting to the KOSS folk at RMAF and they were telling me that KSC35, KSC75 and sportapro all use the same driver - no idea if this is true but this is what they said..dB
We all know KSC75s are at least special in that they use titanium-coated diaphragms on the drivers, while the other Koss's use clear plastic diaphragms. So based on that material difference alone it seems those Koss guys at RMAF don't know their stuff. Old posts of people dissecting KSC35s and SportaPros seem to indicate that at least in the past, they use the same S/N drivers that were visually identical as well.
I don't think it'd be possible to really know for sure unless a SportaPro is measured too, under the same conditions (if KSC35s were measured with the earclips, then the SportaPro drivers need to be transplanted onto those clips too before measurement).
The main reason why I'm wondering about the ksc35 vs sportapro is because the latter is about half the price of the former, and heck if they do indeed use the same drivers then suddenly sportapros might overtake ksc75's as the value king.
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I have the KSC35, KSC75 and KSC50 (the one before the KSC75) and also owned the PortaPro and SportaPro in the same period as when I owned the 35/50/75.
Don't care for all the other Koss HP's to be honest but admit I did not hear most of them and also not the ESP950 :(.
Price range differs a bit as well... ;)
I started my search with the KTX-Pro1 which sounded boomy but got me curious about Koss portable HP's.
On some of those when you hold it against the light you can see a coating vaporized on the diaphragm and the plastic frame also differs from color.
I found the Sportapro to sound bad comparatively and mostly in the lows and top end.
Could not discern much difference beteen the 35 and 75 though many say the differences are noticeable.
production spread or other cause ?
For me the 35 and 75 worked 'best', followed by the 50 and PortaPro the SportaPro was sounding worst.
I did notice that if you press them against your ear with about the same 'force' they started to sound more similar though.
This prompted me to experiment a little.
Since they all (except the KSC50) have the same mechanmism for holding the earcups in place you can unclip them and mount them on another holder.
After swapping drivers around and some listening tests all on the KSC35 holder I could not tell the difference between the drivers and the 35 driver in the SportaPro frame sounded bad.
It was as if the drivers hadn't been switched at all.
For me it is quite clear the spread in SQ is not caused by different drivers and think they all are closely the same.
I couldn't tell any obvious differences between the coated and uncoated drivers personally but that might just be my unability or unwillingness to hear.
I could clearly hear differences between the frames though and think this is because of the differences in swivel action (SportaPro) and the pressure with which they 'seal' the ear.
PortaPro rests on the head KSC35 brace is 'fixed' by the compliance of the thin plastic ring and the 50/75 have more comfortable and 'adjustable' silicone clamps with metal wire in it.
Also ear shape has a LOT of influence on the sound.
The KSC50 was too heavy in weight and 'hung' too much on the ears, also the ear clamp was too thick and less comfortable as the KSC35 and KSC75.
These differences are MUCH bigger than the (to me marginal) differences between the coated and uncoated drivers.
I like those headphones certainly when you do not copmpare them directly with better ones.
To me they are very 'convincing' eventhough they have their deficiences they do not seem to bother me as much as other headphones can.
I can wear them for many hours in a row.
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I have the KSC35, KSC75 and KSC50 (the one before the KSC75) and also owned the PortaPro and SportaPro in the same period as when I owned the 35/50/75.
Don't care for all the other Koss HP's to be honest but admit I did not hear most of them and also not the ESP950 :(.
Price range differs a bit as well... ;)
I started my search with the KTX-Pro1 which sounded boomy but got me curious about Koss portable HP's.
On some of those when you hold it against the light you can see a coating vaporized on the diaphragm and the plastic frame also differs from color.
I found the Sportapro to sound bad comparatively and mostly in the lows and top end.
Could not discern much difference beteen the 35 and 75 though many say the differences are noticeable.
production spread or other cause ?
For me the 35 and 75 worked 'best', followed by the 50 and PortaPro the SportaPro was sounding worst.
I did notice that if you press them against your ear with about the same 'force' they started to sound more similar though.
This prompted me to experiment a little.
Since they all (except the KSC50) have the same mechanmism for holding the earcups in place you can unclip them and mount them on another holder.
After swapping drivers around and some listening tests all on the KSC35 holder I could not tell the difference between the drivers and the 35 driver in the SportaPro frame sounded bad.
It was as if the drivers hadn't been switched at all.
For me it is quite clear the spread in SQ is not caused by different drivers and think they all are closely the same.
I couldn't tell any obvious differences between the coated and uncoated drivers personally but that might just be my unability or unwillingness to hear.
I could clearly hear differences between the frames though and think this is because of the differences in swivel action (SportaPro) and the pressure with which they 'seal' the ear.
PortaPro rests on the head KSC35 brace is 'fixed' by the compliance of the thin plastic ring and the 50/75 have more comfortable and 'adjustable' silicone clamps with metal wire in it.
Also ear shape has a LOT of influence on the sound.
The KSC50 was too heavy in weight and 'hung' too much on the ears, also the ear clamp was too thick and less comfortable as the KSC35 and KSC75.
These differences are MUCH bigger than the (to me marginal) differences between the coated and uncoated drivers.
I like those headphones certainly when you do not copmpare them directly with better ones.
To me they are very 'convincing' eventhough they have their deficiences they do not seem to bother me as much as other headphones can.
I can wear them for many hours in a row.
Ironically I find KSC75s to sound much better when mounted on a headband (e.g. portapro headband); the lower end gets boosted and the mids clear up because the driver gets pushed much closer to the ears, resulting in a more balanced sound. The StratoKOSSer is basically that, plus a cup with foam.
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I think the biggest debate about which one sounds best to who is mostly about the ear shape and fit of the earpad against the ears.
For one person the clip type may work best, for another the headband type, with or without the headrest-pads.
Also taste may have something to do with it as well as preference with how they are connected to the ears (clip or headband) for comfort.
When a headphone is uncomfortable, even if they sound excellent, it still won't get much headtime and is rated lower in general.
The drivers themselves do not seem to cause the relatively large differences in perceived SQ.
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The SportaPro uses the exact same drivers as the Ksc35; they are just mounted on the crappy SportaPro headband, instead of the Ksc35 clips.
Got myself a pair of SportaPros for $17, and indeed the sound signature mirrored the measurements here, with the distinct "demon horns" colouration in the treble region, and smoothness throughout everywhere else.
I threw away the SportaPro headbands (which due to the amount of plastic, negatively impacted the back venting of the drivers and the resulting sound) and instead mounted these on the much less acoustically intrusive PartsExpress headband and man, the sound quality gets ridiculous. By having the drivers pressed against your ears helps bring the midrange out also, which makes the sound all the more tonally balanced.
It is indeed smoother-sounding, and fuller-sounding, than my Ksc75s. Also notable was the fact that it sounded best without any cover-grill mods; my kramer modded cover-grill made these sound atrocious.
Really think that SportaPros (aka Ksc35s without clips) + PartsExpress headband is by far the best SQ:$ ratio deal out there atm.
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How the end product (Ksc35/SportaPro drivers + PartsExpress headband) looks.
(http://i.imgur.com/iNF6gj8.jpg)
(http://i.imgur.com/aTToSFF.jpg)
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Just got two pair of KSC75's for $20 on Amazon...think they will be good for the family!
(I didn't see the KSC35 as available.)
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Just got two pair of KSC75's for $20 on Amazon...think they will be good for the family!
(I didn't see the KSC35 as available.)
Yeah, I think you can get the KSC35 drivers if you get the Sporta Pros, though you might be able to buy them directly from Koss. Closer to $45 tho :'(
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Just got two pair of KSC75's for $20 on Amazon...think they will be good for the family!
(I didn't see the KSC35 as available.)
Yeah, I think you can get the KSC35 drivers if you get the Sporta Pros, though you might be able to buy them directly from Koss. Closer to $45 tho :'(
Yeah there is absolutely no point getting the Ksc35s AS Ksc35s, since you get the exact same thing by paying half the price.
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Bingo the sporta is the unsung deal here. Personally I prefer the 75 drivers on the sporta band as the band is malleable enough to bend into a terrific fit. Sometimes cheap works!
On the driver front. Here is the deal with which model uses what.
the KSC 75 and KTXPRO1 both use the same titanium coated driver.
The Porta Pro (Actually this is the PortaPro Jr. from 1985, but the Senior model died a quick death back then) the KSC 35 and the Sporta Pro all use the same driver. There are various colour differences but the driver and enclosure are all the same.
The only one I never owned is the KTXPRO1 and they are up for 17.99 locally so I might pick up a pair just to see how the Koss headband works with the 75 drivers.
I would be extremely curious to see a Porta Pro CSD overlaid on a Sporta Pro CSD to see what actual difference the vented vs non vented back makes. It is certainly audible enough.
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Nuh-uh, no way the PortaPros share the same driver as the SportaPro/KSC35s, they sound completely different. PortaPro drivers have a very pronounced and slightly loose bass, and somewhat recessed treble, the 35s on the other hand are much more balanced with a bass that is more in-check. Maybe the innards are the same and the drastic sonic difference is due to the driver enclosure difference? Even then the difference is big enough that they might as well be called different drivers.
Also IMO the SportaPro headband does some bad things to the sound quality of whatever drivers are clipped on them, because they don't allow any driver ventilation at the back and end up making the drivers sound too closed / treble too shrill / killing the imaging capabilities. You gotta either drill some big holes on the driver backplate areas of the SportaPro headband, or switch to whole new headbands (e.g. the PartsExpress headband, as I showed in photos a few posts up), to really make the drivers shine. This applies to both KSC35 and KSC75 drivers.
Edit: ignore; the portapro drivers are counterfeit.
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I will guarantee you those drivers are the same. The question that has really been nagging more than a few folks is why they sound soo much different as a clip or sporta. Thats why I am curious to see overlaid CSD charts of the brood.
I find no shrillness with the 75/Sportaband combo, but that may well be due to the amount of bending I put into getting the band where I like it and having the temple pads actually do something. I tried the partsexpress type (I bought a bag O' headphones awhile back and there were a few with that headband) but found it did not clamp quite as well.
One thing I have not tried for who knows what reason is the actual Porta Pro band. I should give that a kick and report back on how that sounds.
It's funny when you look at the Koss site, for the price of a pair of 35's and shipping, you can hit the local box store and buy 2 pairs of Sporta Pros.
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There is really only 1 way to know for sure, is if Purrin could measure some PortaPro drivers and see if they have the same FR/CSD patterns as the KSC35 measurements, around the midrange~treble.
I am still convinced they are vastly different. I do have some PortaPro drivers (one of them shorted out but the other driver works fine), and just playing music through it, compared to through a free-hanging Ksc35, the bass/nonbass balance difference is extremely obvious. There is some overwhelmingly strong bass with the PortaPro drivers even when they are just held up to my ear with my hands, relative to the Ksc35/SportaPro drivers (maybe 10 dB difference in bass/lower midrange). This difference is overwhelming.
Seriously, you have both Portapros and ksc35 drivers too right? Try the same test (just play music through either, and just lightly hold up one driver to your ear and roughly gauge its tonal balance, then quickly switch to the other pair of drivers).
The driver casing do look identical though, other than the plastic colour difference.
To my preference the Ksc35 drivers on Partsexpress headband (loose clamp) gives the best tonal balance out of all these variations (ksc75/35/porta on earclips/portaproband/sportaproband/P.E.band).
It sounds remarkably close to my HE500s, other than a more forward upper midrange, less tonal bass (obviously), and grainier treble. Quite a feat.
Edit: ignore; the portapro drivers are counterfeit.
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I have tried the (blue) drivers of the PortaPro on the KSC35 clip and the (black) SportaPro drivers on the KSC35 clip. The drivers can be pulled off easily and clicked in the other headbands/ear clip.
Problem is auditive memory is short and swapping takes time.
Personally all 3 drivers I could not tell apart on the KSC35 clip.
On the SportaPro clip they were all poo sounding on the PortaPro just slightly less compared to the KSC35.
I would say the differences are marginal at best with MY 3 versions.
The reason the same drivers sound different is because (in my case) the KSC35 'seals' the best as they are pressed against my ears.
In the PortaPro band they rest against my head and as the drivers can tilt and have some depth adjustment can sit reasonably well against my ear.
The SportaPro headband, however, is quite rigid and because of this they do not 'seal' well against my ears making them sound bass shy and a bit shrill.
Of course with on-ears and clip types the 'seal' you get is VERY dependent on the SHAPE of the pinnae and thus also the sound. IMO the major reason why some find the 75/35 to sound best and others the PortaPro
I can hear slight differences between the 35 and 75 (didn't swap clips between those) but blame it on the way they are pressed against my ear (KSC75 is more pleasant over longer periods due to the 'adjustable' pressure of the silicone clip. Differences might also be from driver type (the membranes are not exactly the same as one of them is titanium 'flashed' after all)
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I have tried the (blue) drivers of the PortaPro on the KSC35 clip and the (black) SportaPro drivers on the KSC35 clip. The drivers can be pulled off easily and clicked in the other headbands/ear clip.
Problem is auditive memory is short and swapping takes time.
Personally all 3 drivers I could not tell apart on the KSC35 clip.
On the SportaPro clip they were all poo sounding on the PortaPro just slightly less compared to the KSC35.
I would say the differences are marginal at best with MY 3 versions.
The reason the same drivers sound different is because (in my case) the KSC35 'seals' the best as they are pressed against my ears.
In the PortaPro band they rest against my head and as the drivers can tilt and have some depth adjustment can sit reasonably well against my ear.
The SportaPro headband, however, is quite rigid and because of this they do not 'seal' well against my ears making them sound bass shy and a bit shrill.
Of course with on-ears and clip types the 'seal' you get is VERY dependent on the SHAPE of the pinnae and thus also the sound. IMO the major reason why some find the 75/35 to sound best and others the PortaPro
I can hear slight differences between the 35 and 75 (didn't swap clips between those) but blame it on the way they are pressed against my ear (KSC75 is more pleasant over longer periods due to the 'adjustable' pressure of the silicone clip. Differences might also be from driver type (the membranes are not exactly the same as one of them is titanium 'flashed' after all)
I don't even need to press the free drivers against the ear to hear the drastic bass difference between my PortaPro driver and Ksc35 ones. The bass/lower mids just drowns out everything with the portapro driver even when it's hovering against the ear, completely different from the Ksc35 driver which has tons more clarity and less bass/lower mids. It's not even a matter of short-term auditory memory / swapping time, they are starkly different-sounding to me. Heck even the Ksc75s sound closer to my Ksc35 drivers than the Portapros ones.
Edit: ignore; the portapro drivers are counterfeit.
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I have tried the (blue) drivers of the PortaPro on the KSC35 clip and the (black) SportaPro drivers on the KSC35 clip. The drivers can be pulled off easily and clicked in the other headbands/ear clip.
Problem is auditive memory is short and swapping takes time.
Personally all 3 drivers I could not tell apart on the KSC35 clip.
On the SportaPro clip they were all poo sounding on the PortaPro just slightly less compared to the KSC35.
I would say the differences are marginal at best with MY 3 versions.
The reason the same drivers sound different is because (in my case) the KSC35 'seals' the best as they are pressed against my ears.
In the PortaPro band they rest against my head and as the drivers can tilt and have some depth adjustment can sit reasonably well against my ear.
The SportaPro headband, however, is quite rigid and because of this they do not 'seal' well against my ears making them sound bass shy and a bit shrill.
Of course with on-ears and clip types the 'seal' you get is VERY dependent on the SHAPE of the pinnae and thus also the sound. IMO the major reason why some find the 75/35 to sound best and others the PortaPro
I can hear slight differences between the 35 and 75 (didn't swap clips between those) but blame it on the way they are pressed against my ear (KSC75 is more pleasant over longer periods due to the 'adjustable' pressure of the silicone clip. Differences might also be from driver type (the membranes are not exactly the same as one of them is titanium 'flashed' after all)
I don't even need to press the free drivers against the ear to hear the drastic bass difference between my PortaPro driver and Ksc35 ones. The bass/lower mids just drowns out everything with the portapro driver even when it's hovering against the ear, completely different from the Ksc35 driver which has tons more clarity and less bass/lower mids. It's not even a matter of short-term auditory memory / swapping time, they are starkly different-sounding to me. Heck even the Ksc75s sound closer to my Ksc35 drivers than the Portapros ones.
I am not hearing the difference bare bones (no band no earclip just pressed against the ears). I wonder if there is something else at play here. Perhaps Koss modifying the drivers over time? Manufacturing defect in the grilles? I'm gobsmacked. :-S
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I don't even need to press the free drivers against the ear to hear the drastic bass difference between my PortaPro driver and Ksc35 ones. The bass/lower mids just drowns out everything with the portapro driver even when it's hovering against the ear, completely different from the Ksc35 driver which has tons more clarity and less bass/lower mids. It's not even a matter of short-term auditory memory / swapping time, they are starkly different-sounding to me. Heck even the Ksc75s sound closer to my Ksc35 drivers than the Portapros ones.
It may be a long shot:
http://loveray.blogspot.nl/2010/12/how-to-identify-fake-koss-porta-pro.html
I have owned (and even traded a few) KSC50's and even still keep one of those for spare drivers which are the predecessors of the KSC75 and have 3 KSC75's (one was used by the wife before I gave her a HD238). One of them died after I soldered off an intermittent wire. Have 2 of those left. 1 at home, one at the office.
Had 2 PortaPro's (both sold now) and 1 SportaPro, also sold (even had a KTX-Pro 1 for a while).
I found all of them to sound closely the same when used under the same conditions and would not be able to tell them apart blindfolded.
It may be my lack of hearing abilities (have been accused of this before :)p8 ) but seriously doubt this.
There may be some spread in production but a very obvious spread I have not encountered with all the Koss's I owned.
Except for the KTX-Pro1 which is a completely different and dark headphone.
Indeed it is likely something else is going on.
(http://graphs.headphone.com/graphCompare.php?graphType=0&graphID[]=1023&graphID[]=1613&graphID[]=1623&graphID[]=413&scale=30)
When I have some time I will also measure my KSC75's and KSC50 (already measured the KSC35) which may not be accurate in an absolute sense but can be used comparatively.
Do not have Portapro and Sportapro any more.
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I don't even need to press the free drivers against the ear to hear the drastic bass difference between my PortaPro driver and Ksc35 ones. The bass/lower mids just drowns out everything with the portapro driver even when it's hovering against the ear, completely different from the Ksc35 driver which has tons more clarity and less bass/lower mids. It's not even a matter of short-term auditory memory / swapping time, they are starkly different-sounding to me. Heck even the Ksc75s sound closer to my Ksc35 drivers than the Portapros ones.
It may be a long shot:
http://loveray.blogspot.nl/2010/12/how-to-identify-fake-koss-porta-pro.html
I have owned (and even traded a few) KSC50's and even still keep one of those for spare drivers which are the predecessors of the KSC75 and have 3 KSC75's (one was used by the wife before I gave her a HD238). One of them died after I soldered off an intermittent wire. Have 2 of those left. 1 at home, one at the office.
Had 2 PortaPro's (both sold now) and 1 SportaPro, also sold (even had a KTX-Pro 1 for a while).
I found all of them to sound closely the same when used under the same conditions and would not be able to tell them apart blindfolded.
It may be my lack of hearing abilities (have been accused of this before :)p8 ) but seriously doubt this.
There may be some spread in production but a very obvious spread I have not encountered with all the Koss's I owned.
Except for the KTX-Pro1 which is a completely different and dark headphone.
Indeed it is likely something else is going on.
(http://graphs.headphone.com/graphCompare.php?graphType=0&graphID[]=1023&graphID[]=1613&graphID[]=1623&graphID[]=413&scale=30)
When I have some time I will also measure my KSC75's and KSC50 (already measured the KSC35) which may not be accurate in an absolute sense but can be used comparatively.
Do not have Portapro and Sportapro any more.
Thanks for that graph. Your my new hero headbang
I had never considered the counterfeit angle, but in this day and age you have to assume its possible. If they could do Trek bikes and inject them right into the NA distribution system, anythings possible.
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I don't even need to press the free drivers against the ear to hear the drastic bass difference between my PortaPro driver and Ksc35 ones. The bass/lower mids just drowns out everything with the portapro driver even when it's hovering against the ear, completely different from the Ksc35 driver which has tons more clarity and less bass/lower mids. It's not even a matter of short-term auditory memory / swapping time, they are starkly different-sounding to me. Heck even the Ksc75s sound closer to my Ksc35 drivers than the Portapros ones.
It may be a long shot:
http://loveray.blogspot.nl/2010/12/how-to-identify-fake-koss-porta-pro.html
I have owned (and even traded a few) KSC50's and even still keep one of those for spare drivers which are the predecessors of the KSC75 and have 3 KSC75's (one was used by the wife before I gave her a HD238). One of them died after I soldered off an intermittent wire. Have 2 of those left. 1 at home, one at the office.
Had 2 PortaPro's (both sold now) and 1 SportaPro, also sold (even had a KTX-Pro 1 for a while).
I found all of them to sound closely the same when used under the same conditions and would not be able to tell them apart blindfolded.
It may be my lack of hearing abilities (have been accused of this before :)p8 ) but seriously doubt this.
There may be some spread in production but a very obvious spread I have not encountered with all the Koss's I owned.
Except for the KTX-Pro1 which is a completely different and dark headphone.
Indeed it is likely something else is going on.
(http://graphs.headphone.com/graphCompare.php?graphType=0&graphID[]=1023&graphID[]=1613&graphID[]=1623&graphID[]=413&scale=30)
When I have some time I will also measure my KSC75's and KSC50 (already measured the KSC35) which may not be accurate in an absolute sense but can be used comparatively.
Do not have Portapro and Sportapro any more.
!!! Much thanks for linking me that. Yeah it took me 1 minute comparing to realize that what I have are indeed counterfeits. Wow. These were bought by my roommate a few years ago and then passed to me when he got better cans, looks like he ordered from the wrong places. Seems as though what I said earlier are all null.
Now I'm beginning to realize that the "bass monster" status of PortaPros in the headphone communities might be entirely unfounded - most people probably got fake bass-heavy units!