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Stax SR-009S Electrostatic Headphone Review

Rate this headphone:

  • 1. Poor (headless panther)

    Votes: 47 20.3%
  • 2. Not terrible (postman panther)

    Votes: 63 27.3%
  • 3. Fine (happy panther)

    Votes: 80 34.6%
  • 4. Great (golfing panther)

    Votes: 41 17.7%

  • Total voters
    231

markanini

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If a $5k product *begs* for *major* EQ, in my opinion it is a flawed design. This frequency response out of the box in a $5K product is a joke, and I doubt there has been much worse on this website:

View attachment 307714

You *did* mention in your conclusions you wished they'd done a better job for "out of the box" sound. To me - I think that is a mandatory requirement to command the price tag. I did mention I was sorely disappointed when I got my Stax stuff back in the day. And I wonder how many people that use the headphones go and EQ them for accuracy.

Again, my point is made respectfully. I know there is a a Stax cult out there, and all my posts on this website show I completely approve of personal choices.
It's doubtful that Harmans in-room curve looked much better before smoothing. It's not hard to come up with valid critique of this product, before anyone accuses me of running a defence.
 

brandall10

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beyond what is measured with frequency response and distortion.

If we ignore Impulse/waterfall then we're we're dealing with quantum unobtanium.

In the real world, when there is new information to reproduce, a particular material will take so long to respond, and when it no longer exists, to return to a steady state.

It stands to reason, everything else equal, a material that has less mass should react quicker.
 
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pablolie

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It's doubtful that Harmans in-room curve looked much better before smoothing. It's not hard to come up with valid critique of this product, before anyone accuses me of running a defence.

I will never attack personal choices. It's a bit like arguing about favorite colors. :)
 

Robbo99999

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In the real world, when there is new information to reproduce, a particular material will take so long to respond, and when it no longer exists, to return to a steady state.

It stands to reason, everything else equal, a material that has less mass should react quicker.
I think this is a red herring that people sometimes include - "speed of the driver" or something, which is what you're talking about here. It's all included in the frequency response & distortion in terms of it's capabilities. As far as I understand it's explainable in mathematical terms, something about a Fourier Transform, but I don't understand it. Oratory or a few others on this website would be able to explain it to you though - all the information is encapsulated in the frequency response & distortion.
 

Keith_W

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I have listened to the same headphone in several setups, but I have never seen measurements of it. This review confirms my subjective impression - it is bass shy, but it has amazing spatial qualities. I know I am sounding like a subjectivist but the top end has a certain lack of coloration and delicacy as if the sound is emerging from thin air. I voted golfing panther.
 

solderdude

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I think this is a red herring that people sometimes include - "speed of the driver" or something, which is what you're talking about here. It's all included in the frequency response & distortion in terms of it's capabilities. As far as I understand it's explainable in mathematical terms, something about a Fourier Transform, but I don't understand it. Oratory or a few others on this website would be able to explain it to you though - all the information is encapsulated in the frequency response & distortion.

Yep that is true, at the eardrum.

Too bad measurements above 6kHz start to be inaccurate and above 8kHz even more so and are completely inaccurate above 9kHz so whatever information is encapsulated in the measured frequency response will say nothing about the speed, attack and decay of the actual driver and how that interacts with someone's ears.

The measurements are only referenced to a standard and in this case only to a certain fit on a specific fixture as well. So safe to say we know nothing about the treble performance other than 1 measurement to 1 standard fixture in the position Amir measured it in against an overly smoothed/averaged target developed using a slightly different pinna as well.
That's all. It is indicative and not hard reality.
 
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brandall10

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I think this is a red herring that people sometimes include - "speed of the driver" or something, which is what you're talking about here. It's all included in the frequency response & distortion in terms of it's capabilities. As far as I understand it's explainable in mathematical terms, something about a Fourier Transform, but I don't understand it. Oratory or a few others on this website would be able to explain it to you though - all the information is encapsulated in the frequency response & distortion.

Distortion/FR is a steady state measurement, no? Impulse/decay is response over time to changing input. Is it the case that something which produces high distortion at a particular frequency at a particular volume, will consequently lose energy to distortion speeding up/slowing down and have a slower rate of change? Even still, we need to have all the measurements at various levels to achieve what that response is. Taking distortion plots at a few levels will give a picture but won't tell the whole story.

Have a link to what you're thinking of, oratary or otherwise? Glancing at a few articles on waterfall plots not finding mention of using distortion for derivation or vice versa.
 
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Robbo99999

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Yep that is true, at the eardrum.

Too bad measurements above 6kHz start to be inaccurate and above 8kHz even more so and are completely inaccurate above 9kHz so whatever information is encapsulated in the measured frequency response will say nothing about the speed, attack and decay of the actual driver and how that interacts with someone's ears.

The measurements are only referenced to a standard and in this case only to a certain fit on a specific fixture as well. So safe to say we know nothing about the treble performance other than 1 measurement to 1 standard fixture in the position Amir measured it in against an overly smoothed/averaged target developed using a slightly different pinna as well.
That's all. It is indicative and not hard reality.
Yep, I'm aware that measurements on fixtures are only a general indication of overall level in that area above 10kHz - which is why people like Oratory often just use High Shelf EQ Filters in that area in their EQ's.
Distortion/FR is a steady state measurement, no? Impulse/decay is response over time to changing input. Is it the case that something which produces high distortion at a particular frequency at a particular volume, will consequently lose energy to distortion speeding up/slowing down and have a slower rate of change? Even still, we need to have all the measurements at various levels to achieve what that response is. Taking distortion plots at a few levels will give a picture but won't tell the whole story.

Have a link to what you're thinking of, oratary or otherwise? Glancing at a few articles on waterfall plots not finding mention of using distortion for derivation or vice versa.
I've found this from Oratory1990:
https://www.reddit.com/r/oratory1990/comments/ocl1je/_/h40dqto
 

Ra1zel

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There is no standard that is going to make this look good.
View attachment 307905
‘… some things that look gross in the frequency response, the ear says, “I don’t care”.’
– Siegfried Linkwitz

So why even bother measuring them or any other headphone for that matter. By your explanation practically every headphone should be golden since you can just EQ it? :facepalm:
SR-009S will respond to EQ much better than 99% of headphones since its distortionless even in bass, and yes EQ is invaluable tool when it comes to headphones
Lol I expect to get a product that does not NEED eq to fix it's issues for 4500.00.
Tts like saying that you expect expensive stove to cook you a meal, the issues will be there irrespective of headphones, due to your very own head-related transfer function.
 

Jmitch

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Glad to see this review, long time follower, first time poster. I've been a Stax fan for a long time and would like to improve my experience of them by trying some equalization. Can anyone recommend an EQ device that could be integrated with my Stax systems? A complete newb here, what do I use, and where does it go? I assume it has to go after the headphone amplifier? My best Stax system is the older SR-007's with the Stax tube amp, which is widely thought to be underpowered, but would like to try boosting the bass with parametric EQ. They are pretty good at the lowest bass, but lack punch at mid-bass. All in all, I usually just leave them in the box and use dynamic phones since those've gotten so good. Thanks for any tips.
 

Jimbob54

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Glad to see this review, long time follower, first time poster. I've been a Stax fan for a long time and would like to improve my experience of them by trying some equalization. Can anyone recommend an EQ device that could be integrated with my Stax systems? A complete newb here, what do I use, and where does it go? I assume it has to go after the headphone amplifier? My best Stax system is the older SR-007's with the Stax tube amp, which is widely thought to be underpowered, but would like to try boosting the bass with parametric EQ. They are pretty good at the lowest bass, but lack punch at mid-bass. All in all, I usually just leave them in the box and use dynamic phones since those've gotten so good. Thanks for any tips.
What / where are your sources? If we are talking digital sources (streamed or locally stored files) the obvious place to EQ is in or just after the player software. Or, put another way, before or in the device doing the digital to analog conversion.

If you are talking analog sources or CDs, then things get more expensive and complex.
 

solderdude

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which is why people like Oratory often just use High Shelf EQ Filters in that area in their EQ's.

Yep but that may well be incorrect. He adds this by listening to the headphone and adjusting the shelf and is not based on measurements.
 

Jmitch

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What / where are your sources? If we are talking digital sources (streamed or locally stored files) the obvious place to EQ is in or just after the player software. Or, put another way, before or in the device doing the digital to analog conversion.

If you are talking analog sources or CDs, then things get more expensive and complex.
For the sake of discussion, I generally have output (balanced) directly from a Sony SCD-XA5400ES, using CD or SACD discs. I sometimes connect to a Mac mini using Audirvana Plus and an external DAC. Guess that's easier (use software). But would love to try analog balanced on the old Sony ES player.
 

Jimbob54

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For the sake of discussion, I generally have output (balanced) directly from a Sony SCD-XA5400ES, using CD or SACD discs. I sometimes connect to a Mac mini using Audirvana Plus and an external DAC. Guess that's easier (use software). But would love to try analog balanced on the old Sony ES player.
I think you are in the realms of some of the MiniDSP devices for the Sony analog out.

Or if you want to splash the cash, rme adi 2 pro.
 

Robbo99999

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Yep but that may well be incorrect. He adds this by listening to the headphone and adjusting the shelf and is not based on measurements.
Yep, I agree inasmuch that's why that High Shelf Filter is listed as one of his user customisation filters, created to be manipulated & changed by the end user after listening to their headphone. In my experience though I've worked out roughly where I want to see the response in GRAS measurements above 10kHz, I like to see it a little bit below the 1kHz SPL level.....so for me I'd EQ first on the basis of the measurement and then listen to it to decide.....so I think there is some good general relevance to the measurement above 10kHz in my experience.
 

solderdude

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I have never seen measurements of it.
ora 009S.png
crin 009S.png


Both do not state which energizer is used though.
 

BrooklynNick

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There is a widespread belief among STAX users in various forums that the amp makes a dramatic difference to how the headphones sound. The claim is that the amp makes a much bigger difference to how an electrostatic headphones sounds than it does for a dynamic or planar headphone.

I've done some subjective A/B comparisons and find that the amp does make a difference, but much less than many seem to believe.

It would be amazing service to the community if @amirm could do amp/headphone measurements to answer this once and for all. For example, measuring the STAX SR-009S with a few different amps at different price points. Without this information, there will always be a question if ASR electrostatic headphones measurements reflect the headphone's performance or are showing the limitations of the amp.
 
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