[DecentLevi]

 
Thanks for the detailed impressions! I feel about the same way about the 950 compared to the 6x0 series. I've heard them both on a lot of different setups and come away feeling like they are basically on the same level with each having its own strengths and weaknesses. I ended up keeping the 950 because over time I came to really appreciate its very even handed presentation. I think it's one of its biggest strengths when I compare it to other phones. I do remember thinking it was bit dull during the first month or so though. They are both excellent values IMO. 

So you think it's mostly just brain burn-in that I need to adjust? Or maybe also a DAC swap?
 
Also, knowing the diaphragm is so thin I feel afraid to turn the volume up very loud for fear of blowing it out. Or is this misplaced?

 

[DecentLevi]

Also @recarcar, from an earlier discussion elsewhere - I would like to say that a perfect "bass seal" is not important for an electrostatic headphone. My take is that electrostats already create bass frequencies inside the cup, whereas dynamics rely on a good seal in order for the bass to be audible, and this is why the ESP 950's have a clamping force that is neither loose nor tight, in order to get the best sound. 
 
So I would be somewhat skeptical if your earpad mod with adding extra foam had actually increased the bass response - are you sure about the sonic differences or do you think it may be a placebo effect?

 

[recarcar]

  So you think it's mostly just brain burn-in that I need to adjust? Or maybe also a DAC swap?
 
Also, knowing the diaphragm is so thin I feel afraid to turn the volume up very loud for fear of blowing it out. Or is this misplaced?

In my experience the ESP950 is pretty DAC dependent. I've actually just been using it with vinyl and have been satisfied. 
 
I think that you basically described its nature well though. It is a pretty detailed phone (slightly more so than the 6x0 IMO, at least with the rigs I've heard them on) and to me it gives me a clearer picture of what is happening - less gray/fuzzy. BUT, it lacks the tactility of very good dynamics like the 6x0. I would not toss them out right away, because you might grow to appreciate how even handed it is, but you may not like its relatively soft nature in general. But it is to me, its biggest weakness. 
 
Even a very modest vinyl rig like mine helps a bit with tactility but I think its nature is just kind of soft and in my experience of it on different setups, it doesn't improve all that much. I spent a few years with the HD600 and still think its a great phone and would probably take it over the ESP950 if I could afford a TOTL rig. But as it is now, with my modest stuff, the ESP950 gives me a bit more clarity/detail and relative neutrality than the 6x0 does, which I wanted a little more than dynamic punch and tactility. 

 

[recarcar]

  Also @recarcar, from an earlier discussion elsewhere - I would like to say that a perfect "bass seal" is not important for an electrostatic headphone. My take is that electrostats already create bass frequencies inside the cup, whereas dynamics rely on a good seal in order for the bass to be audible, and this is why the ESP 950's have a clamping force that is neither loose nor tight, in order to get the best sound. 
 
So I would be somewhat skeptical if your earpad mod with adding extra foam had actually increased the bass response - are you sure about the sonic differences or do you think it may be a placebo effect?

Definitely could be placebo, but I think that the extra padding actually helps with positioning the headphone on my head/face which might have an effect on the response. I actually did it initially out of comfort (my ear touch the inside of the cup), not expecting it to make any difference. I do notice a bit more bass, but it could definitely be placebo. 
 
In any case, it a super easy mod and reversible so there was no issue with just trying it out. 

 

[obobskivich]

So you think it's mostly just brain burn-in that I need to adjust? Or maybe also a DAC swap?

Also, knowing the diaphragm is so thin I feel afraid to turn the volume up very loud for fear of blowing it out. Or is this misplaced?

I'd say misplaced - the Koss spec for them is something around 135 dB continuous output (you'll be deaf long before you realize there's a problem). The diaphragm is very thin but it's fairly strong material as long as you don't take a knife to it or anything reckless (that said, I've seen MartinLogan demos where they punch holes in their diaphragms with pencils and then the speakers continue to play just fine - I'm not at all advocating someone try this out, but the point is that estats are pretty mechanically resilient).

Also @recarcar
, from an earlier discussion elsewhere - I would like to say that a perfect "bass seal" is not important for an electrostatic headphone. My take is that electrostats already create bass frequencies inside the cup, whereas dynamics rely on a good seal in order for the bass to be audible, and this is why the ESP 950's have a clamping force that is neither loose nor tight, in order to get the best sound. 

As blunt as this is going to sound: no, not really. Closed headphones generally rely moreso on a good seal, but closed electrostatic headphones are largely a thing of the past (e.g. all of the prior Koss ESP models). The ESP/950s are open-back, and like open-back dynamics, seal is a somewhat different discussion as they don't rely on a closed capsule behind the driver. Seal still matters on the "front" side though, don't believe me? hold the headphones an inch or so out from your ears (where there's no seal whatsoever) and give a listen. Electrostats (like any other planar design) are less placement sensitive though, because the entire transducer is a uniform radiating surface, and in the case of the 950 the drivers are pretty big (at one time they were the largest electrostatic drivers ever put into a headphone, but I think some of the newer STAX models may have eclipsed that by now). This contrasts to dynamic designs, especially that rely on angled/specifically positioned drivers where placement can become much more significant wrt overall sound.


WRT ESP/950 and the Sennheisers, imho the ESP/950 are a "grown up" version of the Sennheiser - more detailed, much faster, much cleaner, much less veiled, better treble extension and clarity, tighter bass, etc. I do agree about the "less impactful" presentation compared to a dynamic, and IME this holds true of other 'stats as well - it's a blessing and a curse. On one hand it gives them that "beautiful, ethereal sound" and on the other, "less impactful, less dynamic presentation."

 

[ardgedee]

I'd say misplaced - the Koss spec for them is something around 135 dB continuous output (you'll be deaf long before you realize there's a problem). The diaphragm is very thin but it's fairly strong material as long as you don't take a knife to it or anything reckless (that said, I've seen MartinLogan demos where they punch holes in their diaphragms with pencils and then the speakers continue to play just fine - I'm not at all advocating someone try this out, but the point is that estats are pretty mechanically resilient).

 
I suspect that Martin-Logan demo wouldn't apply, because a puncture affects a smaller portion of the surface area in a speaker than in a headphone. And this also reminds me that small tears in Quad ESLs diaphragms were supposed to be audibly evident, so transducer design may have something to do with it.
 
As for most speakers, the best way to avoid damage from excessive volume is to ensure the amplifiers (not just the amp itself, but any other gain-providing circuits, such as preamps) have sufficient headroom to avoid clipping. And to maybe not listen so loud; with good-quality audio equipment you can get detailed sound without having to blast your ears.
 
Since the 950's earpieces are detachable, it's easy to find out how they sound while pressed to your head, away from your ears, or at various angles.
 
fwiw, Stax was making a closed-back headphone, the 4070, in the early 2000s. Since it was built-to-order rather than a regular production item, I don't know if it's still available.

 

[obobskivich]

I suspect that Martin-Logan demo wouldn't apply, because a puncture affects a smaller portion of the surface area in a speaker than in a headphone. And this also reminds me that small tears in Quad ESLs diaphragms were supposed to be audibly evident, so transducer design may have something to do with it.

Certainly a good point, and I wasn't meaning anyone should test ML's claim (even on ML speakers) - just that 'stats are more durable than people may give them credit for.

As for most speakers, the best way to avoid damage from excessive volume is to ensure the amplifiers (not just the amp itself, but any other gain-providing circuits, such as preamps) have sufficient headroom to avoid clipping. And to maybe not listen so loud; with good-quality audio equipment you can get detailed sound without having to blast your ears.

Aye. And the E/90 will provide that for the ESP/950, as long as you don't clip the input into it.

fwiw, Stax was making a closed-back headphone, the 4070, in the early 2000s. Since it was built-to-order rather than a regular production item, I don't know if it's still available.

They were built-to-order for studio/professional users and have since been discontinued (due to low demand iirc). Koss exclusively built closed-back 'stats until the introduction of the ESP/950 in ~1990, and (reportedly) produces a medical market ESP/900 that is closed-back and is designed to be safe inside of an MRI unit - no idea what those cost and I've never seen pictures of them, just heard that they're apparently out there.

 

[elwappo99]

Has anyone used one of these with a linear power supply, not the brick like the one that's included?
 
I saw one listed up with a Teradak linear power supply and was curious.

 

[wink]

I heard a report from an owner of an ESP/900, and hes said the sound was bassless.
 
I would probably have got one except for that report.

 

[ardgedee]

Koss ... (reportedly) produces a medical market ESP/900 that is closed-back and is designed to be safe inside of an MRI unit - no idea what those cost and I've never seen pictures of them, just heard that they're apparently out there.

 
Looks like somebody had a dozen of them to sell on Ebay at the start of this year, for $300 apiece without energizer or amp. Kind of sorry I missed out on that... kinda not, because it sounded like the seller applied none of their $100 shipping fee towards any effort in safely packaging the item.
 
According to this thread, MRI labs usually have to modify them further to be suitable for use, up to and including removing the transducers entirely and putting them in better, more sound-proof ear cups. It seems that, just like owners of the ESP 950, owners of the ESP 900 are prone to tweaking and optimizing for their needs.

 

[elwappo99]

  I heard a report from an owner of an ESP/900, and hes said the sound was bassless.
 
I would probably have got one except for that report.

 
 
Well, guess I'll tell you how it goes it and my esp950s arrive this week 

.

 

[OJNeg]

  Has anyone used one of these with a linear power supply, not the brick like the one that's included?
 
I saw one listed up with a Teradak linear power supply and was curious.

 
I tried using the sigma11 (a top-notch linear PS) but I honestly didn't notice much of a difference. Best to ditch the E90 altogether IMO

 

[elwappo99]

 

  Has anyone used one of these with a linear power supply, not the brick like the one that's included?
 
I saw one listed up with a Teradak linear power supply and was curious.

 
I tried using the sigma11 (a top-notch linear PS) but I honestly didn't notice much of a difference. Best to ditch the E90 altogether IMO

 
Gah! Don't tell me that!
 
I'm really trying to hold off on searching for a different amp until I at least hear the 950s. 

 

[DecentLevi]

@recarcar I think that's absolutely spot on. The ESP 950's are more clean / detailed / soft, whereas the Senn. HD 5xx / 6xx series are more dynamic with more bass weight. I guess that's the main difference between dynamic and electrostats (?). I've found that I prefer either the dynamic or electrostat headphone depending on how the album was mastered - not even depnding on the genre, but based solely on how it was recorded. Any of you feel the same way? But as mentioned the 950's did seem to overcome some of this 'softness' on the Bifrost Uber DAC. Unless I'm wondering if the SR-009 is punchier than the 950's? I've tried it, noticed no issues with that but don't recall if it hits as hard as the 650's. But I totally agree, I would also take the Sennheiser's over the 950 in a TOTL rig though because those things scale marvelously with higher source chains.

 

[obobskivich]

Thanks for the links for ESP/900 - that's more than I've ever seen about them in the past. As far as not having a lot of bass, that sounds pretty similar to the older closed-back ESP series I have heard (I've heard ESP/6 and owned ESP/10).