Source
r/headphones•
Kerry56

Koss KSC75, Porta Pro and modified Porta Pro

My ten dollar Koss Porta Pro's from Drop showed up today and I did a little testing. I already owned a pair of Porta Pro's but I had modified them years ago to accept Sennheiser HD 25 pads. And I recently purchased a set of KSC75's since I was interested in hearing the differences between these two popular models.

When I got the KSC75, I tried them out on the Koss Porta Pro headband and liked them a lot more on the headband than the original clips. They gain a little bass and the comfort level goes up immensely. I can only wear the clips for about forty minutes before I have to yank them off. Overall, I found the KSC75 fairly similar to my modified Porta Pro, though they were too sharp edged in the upper mids and treble when used as a clip on. I didn't test them against one another extensively, just a couple of casual comparisons.

So my purpose in buying the Drop version of the Porta Pro was to put the KSC75 on this new headband and keep my modified Porta Pro in my stable of regularly used headphones, but that's not the result I got after spending an hour testing them head to head.

My new Porta Pro simply has a lot more warmth, and more mid bass impact, so I'm keeping it as first choice among these three. The KSC75 drivers are now on my old headband, and I've put the modified set of drivers away for use if I ever need them. The modifications are reversible, so not a problem to get the original sound back. The modified set sounded a little distant and washed out compared to the KSC75's on the same headband, and neither have the bass of the new Porta Pro.

Playing Ohh La La by Goldfrapp showed these differences in the mid bass immediately.

Hope that was clear enough.

Posted Nov 6, 2019, 8:10 PM UTC

613
LoppifiedMy DAC costs more than my headphones•

I found that after putting yaxi's on my ksc75 and putting them on my porta pro headband the porta pro drivers were useless to me as the modded ksc75 did everything I liked about the porta pro stock but without sounding incredibly muted in the upper mids/highs

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Kerry56OPO2*SDAC*CAL*X2•

I'm pretty sure that's just the opposite of the sound I prefer. Anything that takes these drivers away from a tight fit on the ear tends to make them brighter. Not what I'm looking for, especially with the KSC75, which has too much of this sound to begin with. I find them to be reasonably good with the headband, but I prefer the stock Porta Pro sound over them by a wide margin.

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LoppifiedMy DAC costs more than my headphones•

ksc75 with yaxi's are warmer than with stock pads, so I'm not sure what you're talking about.

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Kerry56OPO2*SDAC*CAL*X2•

Yaxi's are thicker than the original, thin pads, correct?

Every time I increase the space between my ears and the KSC75 drivers, the sound quality goes down, losing bass quantity and quality, though the difference in the pad thickness may make less of a difference than pressure.

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LoppifiedMy DAC costs more than my headphones•

I find that the yaxi's broaden the hump from the midbass, definitely find it warmer than with stock pads, but that's als because more of the pad is making contact with my ear than with stock pads.

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ConfidentBroH•

tldr this is the sound i prefer so this is what i did

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coldravenge•

Can you please show a picture? If you don’t mind.

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Kerry56OPO2*SDAC*CAL*X2•

Pictures of the stock Porta Pro's are common and the KSC75's don't look much different at all on the Porta Pro headband. The Drop.com Porta Pro is all black. https://imgur.com/Qm8MmNQ

Do you mean the modified pair? It took some time, but I found the pic I posted at headfi years ago. I didn't want to reassemble it. https://imgur.com/HDIKVxM

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coldravenge•

Yes, I meant the modified pair. Thank you for showing me :) I’m gonna do that to my Porta Pro’s.

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Kerry56OPO2*SDAC*CAL*X2•

It will reduce the bass a little. And the HD25 velour pads were expensive even back then. I just happened to have some and made adapter plates for them. Without the plates they are a little too loose, though you could stick them on with some double stick tape.

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coldravenge•

Okay. That sounds a bit complicated to my newbie brain. I guess I’m leaving my Porta Pro’s alone. Haha.

1
Ishouldbeking•

There's definitely a noticeable difference in bass between Portas and KSC75, regardless whether the KSC75's are on a headband. The headband helps add back a bit of bass, but KSC75's are notoriously rolled off down low and don't have the same midbass boost of the Portas. This is generally understood to be the consequence of coating the driver in titanium (which the KSC75's and KTXPRO1 have, but not Portas, Sportas, KPH30i, or KSC35's, which are uncoated and otherwise identical 60 ohm drivers).

As for the earclip comfort of the KSC75's, it's not immediately obvious, but the ear clips can be easily bent to adjust fit and comfort. Whether it's intended for that or not, it's easily reversible and worth a shot if you find them uncomfortable in stock form (or if they're frequently falling off).

I'm personally more of a Sportapro guy myself, but all of these are such great bang for the buck.

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egentligespen•

Yes, in my experience ksc75 has slightly less bass than porta pro, actually as it was meant to be on a headband because it's just right to my ears. While the Porta Pro I have to reduce 1 dB in the bass frequencies to make it sound right to me and opposite up high.

https://diyaudioheaven.wordpress.com/headphones/measurements/koss/ksc75/

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