Koss Porta Pro

Discussion in 'Headphone Measurements' started by ultrabike, Sep 14, 2016.

  1. ultrabike

    ultrabike Measurbator - Admin

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    These headphones need no introduction. They are among the best headphones for the buck one can find. One could argue the KSC75s are a better value, since indeed the sound signature is somewhat similarish and the price is much lower. But the build quality of the PortaPro is much better (even if you factor in a Parts-Express headband for the KSC75s, one of which actually broke on me way too easy).

    Anyhow, I got these off eBay, and the came from China. In such cases one should be concerned about getting a fake, which may very well be the case here. But it was about the only way I would get a black version of these for a reasonable price. Koss should stop monkeying around with Celebrity phones and this and that, and give these an up-lift in looks and stuff.

    Anyhow, these actually sound great and measure as expected. Most folks here have heard these. They are similar to Grados. A bit U-shaped and fairly engaging. They have reasonable extension and balance for the price. Ergonomics are great relative to KSC75s stock and indeed among the most portable phones one can find. These give satisfying bass slam and can provide surprising amounts of detail.

    There seem to be a few black versions of this mini pancakes. This is the one I have:

    [​IMG]

    [​IMG]

    [​IMG]

    The nylon cable option was not available when I bought these. But recabling kit is available for about $9 which I may or may not do later.

    Anyhow here are measurements:

    Frequency Response

    KossPortaPro_fr.png

    Distortion Right

    KossPortaPro_dist_right.png

    Distortion Left

    KossPortaPro_dist_left.png

    CSD Right

    KossPortaPro_csd_right.png

    CSD Left

    KossPortaPro_csd_left.png
     
    Last edited: Sep 15, 2016
  2. ultrabike

    ultrabike Measurbator - Admin

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    Here are some overlays with the KSC75s

    KPPvsKSC75.png

    Perhaps a little more relaxed and more low end extension, but in many way a fairly similar sound signature.

    The question is, can we make these sound like the B&K curve and stuff the way other more linear cans can? The main problem would be to deal with that notch around 4 kHz. Other stuff might not be that bad.

    I gave it a try, and while not perfect I think I got a pretty decent improvement using the convolver stuff that comes with fb2k. I really liked the results after equalization. So here is what we get before and after doing so:

    Right Before and After

    Right_comparo.png

    Left Before and After

    Left_comparo.png

    Right and Left After

    KossPortaProEq.png

    The null and other stuff are not easy to solve. Like they say, "can't make a silk purse out of a pigs ear". Not that these are pigs ears, but there are indeed better more linear cans that will likely cost a bit more. That said, one can proly get pretty good results.

    Here is the equalizer WAV file I came up for these:

    https://drive.google.com/file/d/0BzGhKu7Sq7bCMVlGeVdBMHVGZmM/view?usp=sharing

    BTW, the equalization gives the above results in my measurement rig, which is not absolute in anyway.

    What I can say is that the equalization indeed takes away the u-shape-ness, but the cans may loose some of their impact and "soundstage" capabilities. It's up to the user to determine what he or she likes.
     
    Last edited: Sep 14, 2016
  3. GoodEnoughGear

    GoodEnoughGear Evil Dr. Shultz‎

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    Nice work, that's right on the money. But what is with that trough at 4k?
     
  4. ultrabike

    ultrabike Measurbator - Admin

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    That is common in many supra-aural headphones such as these. It may have to do with some standing wave perhaps. Grados have such issues as well.
     
  5. Armaegis

    Armaegis Friend

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    4kHz... roughly 85mm wavelength. Quarter wavelength is 21mm... roughly the distance from driver to ear canal opening? I dunno, just making stuff up and throwing numbers around. Though I'm not even sure if the quarter wave cancellation thingy even makes sense here.
     
  6. ultrabike

    ultrabike Measurbator - Admin

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    Yeah. Dunno. Could also be the measurement rig.

    EDIT: Actually there is a null around 4.1 KHz when using tone sweeps.
     
  7. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    This Porta pro is THE headphone that brought me into the Hobby. :) . I'll remember forever the day I discovered how good it sounds
     
  8. ultrabike

    ultrabike Measurbator - Admin

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    These are indeed awesome cans. I lost my marbles yet again when I got those yesterday. These are the black edition. Too awesome.
     
  9. Armaegis

    Armaegis Friend

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    I'd be curious to see how the Kramer mods change the measurements.
     
  10. Deep Funk

    Deep Funk Deep thoughts - Friend

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    I gave one of my best friends a Porta Pro. This is one of the best stock headphones I ever tried.

    To find a better stock headphone you have to enter HD600/650 territory.
     
  11. crazychile

    crazychile Eastern Iowa's Spiciest Pepper

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    The PortaPros, KSC-75, KSC-35 are all examples of very reasonably priced headphones that perform well above their price points. I also own a pair of ESP-950s that I really enjoy. Unfortunately Koss also makes some real turds. Their product range can be confusing and they haven't done anything very innovative for decades. I really want to see these guys do well, but they've lost out on a lot of opportunities by not having more viable products in that $100-500 range to compete with Sennheiser, etc.
     
  12. Zed Bopp

    Zed Bopp Friend

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    I have a pair from Amazon, bought a few years ago that I've used on occasion. They have huge and pretty muddy bass + quite messy upper register. It doesn't matter what quality rips I listen to, everything sounds like old 128kbps mp3s rips.

    Either I have fakes (do they even exist?) or I just hear them differently. Or expect way too much. These are on a very different SQ-level than my cheap Aurvana Lives for an example - and those are much better for me anyhow, being somewhat closed for portable use. Cheapos are cool and all, but these just don't cut it for me.

    I wish I still had my old Senn PX100's working for reference. I used to like them a lot back in the day.
     
  13. Deep Funk

    Deep Funk Deep thoughts - Friend

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    The old PX100 was similar to the Porta Pro. Both not the most refined sounding but so much fun that you let the flaws be. For Pop music in particular the old PX100 and Porta Pro are exceptionally well tuned.

    I would say the KSC75 has a more even sound, more neutral-ish but when I want to enjoy faster paced music with some bass the Porta Pro is more fun.
     
  14. ButtUglyJeff

    ButtUglyJeff Stunningly beautiful IRL

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    You know a Portapro/PX100 ii would be a nice shootout to have...

    Maybe even throw in the Monoprice 8323's for good measure
     
  15. Deep Funk

    Deep Funk Deep thoughts - Friend

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    Add the PX90, the successor to the PX100 and PX100 ii. Sennheiser's small folding portable headphones are marvels of design...
     
  16. Armaegis

    Armaegis Friend

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    One thing I always hated about the PortaPro was the little hook used to keep it folded. That bit always scratched my ear.
     
  17. ultrabike

    ultrabike Measurbator - Admin

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    I don't have much of a problem with the hook. One problem however is that the headband opens up and closes and it can indeed pull your hear as it gets caught between the to pieces that make up the headband. This is not a problem with the Parts-Express super-fragile headband for the KSC75s though, since that one is a single piece.
     
  18. ultrabike

    ultrabike Measurbator - Admin

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    Adding @Bill-P's modded Porta Pro measurements:

    Frequency Response

    PortaPro_FR.png

    Distortion Right

    PortaPro_Dist_right.png

    Distortion Left

    PortaPro_Dist_left.png

    CSD Right

    PortaPro_CSD_right.png

    CSD Left

    PortaPro_CSD_left.png
     
  19. Armaegis

    Armaegis Friend

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    Could we get an overlay? Or at least with the same axes/ranges?
     
  20. ultrabike

    ultrabike Measurbator - Admin

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    Sure:

    Comparo W Stock.png
     

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