Koss ESP-950 Over-Ear Headphones

4.43/5 (14 Reviews) MSRP : $999.00


Product Description

  • Frequency Response: 8-35,000 Hz
  • Includes Electrostatic Sterophone, energizer, battery pack, leather carrying case, connecting cables, and 120 VAC adapter
  • Incorporates state of the art electrostatic transducers that operate on currentless electrostatic charges on push-pull capacitor plates to cause movement of the intervening, low-mass semiconductive diaphragm
  • Soft, vinyl closed ear cushion design for isolation
  • Pivoting ear cups and adjustable, detachable headband for comfort and convenience
  • Straight, dual entry 4 foot cord/6 foot extension


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    Reviews 1 - 5 (14 Reviews Total) | Next 15

    User Reviews

    Overall Rating:5
    Value Rating:5
    Submitted by KingFlathead a Audio Enthusiast

    Date Reviewed: November 21, 2015

    Bottom Line:   
    These are amazing headphones. I hear a lot of people complaining about the fact that these headphones sound "bright", or "aren't warm", or don't have "the right color". This is not a bug, it's a feature. In fact, it's THE feature. They operate on different principles.

    Electrostatic diaphragms don't have a lot of the physical limitations that magnetic drivers have, they can respond pretty much instantaneously - they are capacitors, not inductors, and since the diaphragm itself is non-conductive, they are very, very light. Plastics not copper; there's no magnetic field to fight against. What this means is that whatever you put in the back of the amplifier is what you get to hear. They run on a 600V bias, and the signal itself can be up to 2.3KV at max volume, so the current going to them is teeny tiny, and that's great for frequency response. Seriously, these things will physically shake your head with bass, and at the same time deliver extremely crisp highs. This is what happens when you can get away with having something like 12 square inches of totally flat diaphragm over each ear moving back and forth REALLY fast. As a bonus, they are also very, very light. I find the build quality to be quite good, but they are nearly all plastic. I'm sure it's possible to break them, but that's true of anything. Koss being Koss, though, I am not worried. They feel plenty sturdy, and if they ever turn out not to be, they have that awesome lifetime warranty.

    If you like your music to have a particular sound, you are going to need to run it through a preprocessor of some kind. I use a Schiit Bifrost Multibit, and sometimes I need to tweak things to compensate for mixing / mastering / recording problems, as well as for music that must have sounded great when run reproduced through a bunch of tubes, but is missing some equalization when reproduced exactly. This is definitely a factor depending on what you listen to and how you listen to it. If you are running an analog stack, I don't think you'd have the same issues as you're not going for a flat response in the first place, but you may have a harder time making adjustments. I just click stuff for that, so for me, it's good to know that these are as close to a straight digital pipe into my brain as I am going to get as long as the final component in the pipeline is ear-shaped meat.

    The only thing that I can complain about is that there isn't enough clearance around the RCA jacks for proper audio cables, but the back comes off of the energizer very easily and it's a quick fix with a drill bit. It's definitely an annoyance, but not a huge deal. You also need an adapter to use the headphones with a non-Koss energizer, so that's a bit lame, but I can understand the reasoning behind it, since the voltages involved are definitely non-trivial. They come with a 4' cable built in plus a 6' extension, so you can modify the extension without needing to risk getting into anything fragile. If you are buying a fancier electrostatic amp you probably already have what you need or know where to get it.

    In any case, I like them, and you might too. I'd definitely give them a listen first... it's not that they aren't awesome, but they *are* a bit specialized. If flat response is something you like, you'll love these. If that sounds like a problem that needs to be solved, maybe these aren't a great fit. Electrostatics are not electromagnetics, and in my eyes, at least, that's a great thing.

    Expand full review >>

    Used product for:   1 to 3 months

    Duration Product Used:   Audio Enthusiast

    Product model year:   2010



    Overall Rating:3
    Value Rating:3
    Submitted by Reticuli a AudioPhile

    Date Reviewed: January 10, 2006

    Bottom Line:   
    I tried these at CES. They appeared to be designed as a flat response, extremely low distortion headphone for specialized applications, or by some pocket protected engineers who never took the time to listen to them. Maybe they listened to them but have bad taste. Even in speakers you don't want a flat response for enjoyment of commercial product. Headphones are even less flat, since they need to take into account both the expected speaker response and the effects of the room on the tonal balance. These headphones are just flat, kind of like the Etymotic ER4B. There is what we audiophiles like to call a perceived "lift" from the upper mids and beyond with commercial recordins on a flat, high fidelity source. The only way I could see you using the ESP950's as a primary playback device would be as said specialty product (with dummy heads or flat response live mics, including technical applications) or with a very warm preamp, cartridge, or eq in the line somewhere. Otherwise you'd be stuck playing recordings that are either naturally rolled off on top (a lot of acoustic stuff) or mixed/mastered on very bright equipment. Hence all the recommendations in these reviews about needing to use just the right recordings on it. Probably most of the recordings they're refering to are not actually meant to be heard on flat transducers anyway, but aren't necessarily aggressive and unpleasant when presented in such a manner.

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    Used product for:   Less than 1 month

    Duration Product Used:   AudioPhile

    Product model year:   2005

    Purchased At:   none



    Overall Rating:5
    Value Rating:5
    Submitted by Max a AudioPhile

    Date Reviewed: November 19, 2003

    Bottom Line:   
    May i just add one important factor with these fantastic cans. Please make an attempt to use all battery power when listening despite having the rca cord I was in cloud 9 and did not want to leave sonic heaven Very thirsty for juice but i use rechargable - right to the end of red light- with no noticeble lack of quality

    Expand full review >>

    Used product for:   3 Months to 1 year

    Duration Product Used:   AudioPhile

    Product model year:   2003

    Price Paid:    $60000.00

    Purchased At:   friend



    Overall Rating:4
    Value Rating:4
    Submitted by sjp3003 a Audio Enthusiast

    Date Reviewed: November 1, 2002

    Bottom Line:   
    For comparason's sake, I've got a Headroom amp I use to power Sony MDR V900's, Grado SR200's & my top dynamic choice: Sennheisser 580's. The sound source for all is a desktop Nakamichi CD system that I use on my nightable.

    The Koss 950 compares most closely with the Senn's sound. The Senn's have excellent transparency, but the Koss, with its corresponding driver, has even more. Details on the Koss are more precise-- truly impressive. Each instrument is excruciatingly defined.

    The Koss have very high brightness in the mid & high ranges-- in fact this sounds slightly exaggerated compared to the others. Lows are tight & overall good. On the Senns lows are more pronounced though less defined.

    In sum the sound is very high quality.

    Expand full review >>

    Used product for:   Less than 1 month

    Duration Product Used:   Audio Enthusiast

    Product model year:   1999

    Price Paid:    $399.00

    Purchased At:   EBay



    Overall Rating:5
    Value Rating:5
    Submitted by Shawn5454 a Audio Enthusiast

    Date Reviewed: October 12, 2002

    Bottom Line:   
    First of all, these ESP-950's aren't for your average listener. These awesome headphones produce an accurate, detailed & very transparent sound most audiophiles and many amathur audiophiles (I'm in the later group) will enjoy using. Though I'm still more use to a closed-ear style headset, having been weaned on the original Pro4A's, with the liquid filled headphone ear covers back in the late sixties, I found these lightweight headphone cups quite comfortable with their fixable headset assembly. It takes a while for some users to get use to "open-air" phones. IMHO, these are a step or two above the Sennheiser HD 600 which are a quite popular and excellent sounding headphones.

    Due to the nature of electrostatic drivers, they are very sensitive and quite unforgiving of a poor quality signal source, & many untrained amateur audiophiles may find them disappointing if the user has lower quality equipment. Please allow at least 125 hours to properly break in the drivers. With its simple design made for comfort, the lows are quite tight, deep, and smooth; the mid-range is out of this world with strings sound amazing while imaging and soundstage are first class; the upper frequencies are distortion free, transparent, perfectly crystal clear and won't cause chronic fatigue syndrome. -LOL-

    After a hard day's work, a quiet listening session will give you a whole new attitude about the world. As many of you are already asking yourself: "Are they really worth the money?" YES, they're worth every penny! -smile-

    Expand full review >>

    Used product for:   More than 1 year

    Duration Product Used:   Audio Enthusiast

    Product model year:   1996

    Price Paid:    $600.00

    Purchased At:   J&R Catalog




    Reviews 1 - 5 (14 Reviews Total) | Next 15

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