The science behind Stax's magic

[2M2B]

Who are the dudes from Head Fi? I say they are noobs with crap microphones. Mistaking noise from your cheap measurement mic for THD of headphone is classic novice blunder.

No, the ER4PT, or any ER4/3, wont be 0.4% at 100db. More like 2% and that is in the 1KHz+ region.

How are they noobs?, They were testing IEM couplers at 94db where they were questioning THD tests where IEM's with high 2nd order or above 1% above 1KHz were real or the coupler mic was distorting. At 80db the ER4PT was <0.2% with a 0.5% peak at 20Hz on par with many planar drivers, Then the 94db the THD data for the ER4PT look's like a DD was distorting hard to judge the 3rd order is a artifact or actually there. The ER4 charts that you also showed had same problems at 94db of a DD driver distorting at high load.

 

[2M2B]

I dont have any speakers (semi suppressed sobbing)

Speakers that measure same THD as headphones will have much lower THD when playing wide bandwidth signals such as music becose speakers have multiple drivers. Speaker woofer might have 5% THD at 50Hz but due to the multi driver design, the distortion is contained in bass region while in headphones, it will intermodulate everything up to 20 KHz creating full spectrum IMD bukkake.


THD at "1KHz+" doesnt matter much when highest amplitude signals in music are in bass region which also coincides to be the most distortion prone region in headphones. Many planars that have low bass distortion have sharp distortion peaks in mids and highs. There are very few full sized headphones that have under 1% distortion in entire spectrum at 100db.

As to your 99% number, what frequency and what SPL? From the measurements I saw, atleast 95% of headphones reach over 1% THD at some point in spectrum at 100db.


Who are the dudes from Head Fi? I say they are noobs with crap microphones. Mistaking noise from your cheap measurement mic for THD of headphone is classic novice blunder.

No, the ER4PT, or any ER4/3, wont be 0.4% at 100db. More like 2% and that is in the 1KHz+ region.
View attachment 175844

Now your openly trolling, You seem to be clogging up threads with you reaching beyond hard that all Etymotic ER4 is high THD. Blocked.

 

[Garrincha]

I used to own an SR-009 with maxed out Woo Audio WES. Til I picked up a pair of the MrSpeakers Ether Flow Open, a planar magnetic design. The Ethers sounded better. Sold my entire Stax rig.

Sounded better to you.

 

[Garrincha]

Stax magic is simple, ultra low distortion + flat(ish) and smooth FR + flat and smooth phase response + quick decay + planar wavefront + low excursion to spl ratio.

Stax with good seal have very low distortion all across the spectrum. Even with the stupid build in ports and with leaky pads the distortion is only increased in bass to level of average dynamic headphone. The low distortion is the key as it allows low level detail that sits barely above the theoretical perceptual threshold, or as SBAF call it, the "plankton", to be audible becose it isnt lost beneath the sea of intermodulation products like in normal headphones.

They have flat and smooth frequency response and phase response, they do this effortlesly, its inherent characteristic of this technology. The stators are stiff and pass sound easily so they ring less than planar magnetic stators or dynamic drivers and the diaphragms are unusual in their low tension. While planar magnetic headphones need high tension which causes it to ring like small 10 KHz bongo drum, electrostats only need minimal tension with resonant frequency down low around 100 Hz.

The diaphragm also weight very little as it doesnt need to conduct current unlike planars which causes air to strongly damp the fundamental resonance, that is why ported and leaky stats have sharp peak in bass followed by steep roll off while ones with good seal are super flat in bass.

This combination of low diaphragm weight and low tension prevents the diaphragm from having high frequency break up modes, a uneven resonance of the membrane caused by playing HF tones with wavelenght shorter than the size of the membrane.


The massive size of the diaphragm translates to planar wavefront, this makes the ear transfer function to be similiar to real world so it gives them good soundstage. The cherry on top is ratio of excursion to spl which gives them extra low phase intermodulation distortion. They dont need to move very far to move air becose of their large surface area.

To recap, electrostatic drivers are inherently more linear and less resonant than planars and dynamic drivers. Clean THD, clean FR, clean phase and clean CSD create the magic electrostatic sound becose the nonlinearities and resonances of normal headphones that normally hide the micro detail are absent.

This conjunction of explanations seems to me the best try so far. From my listening experiences ( I don't have the SR009 or Sr007, but several Lambdas and a SR 404), the sound experience from Stax headphones simply is distinctly different and it comes down to pure denial trying to reduce every audible aspect of a headphone to FR and noise& distortion.

 

[JamesRF]

This conjunction of explanations seems to me the best try so far. From my listening experiences ( I don't have the SR009 or Sr007, but several Lambdas and a SR 404), the sound experience from Stax headphones simply is distinctly different and it comes down to pure denial trying to reduce every audible aspect of a headphone to FR and noise& distortion.

I tend to agree. I think my preference for dynamic drivers, for example, is to some extent a subjective preference for the sound of the different physics. I've owned and liked the SR-009S, Susvara, Meze - but they all sound a bit synthetic to me. I've always come back to the HD800/HD800S (and, currently, MySphere 3.2).

 

[MayaTlab]

Stax headphones simply is distinctly different and it comes down to pure denial trying to reduce every audible aspect of a headphone to FR

How can you say this since we already know that you've never heard to headphones with the exact same FR at your own eardrum ?
As long as the FR variable isn't controlled, you can't attribute to any other factor the cause of what you're hearing.

 

[Garrincha]

How can you say this since we already know that you've never heard to headphones with the exact same FR at your own eardrum ?
As long as the FR variable isn't controlled, you can't attribute to any other factor the cause of what you're hearing.

You are very monothematic and outright dull in your reasoning. I did, with my own eardrum, which stayed basically the same over the years, listen to a lot of different headphones, including various Stax models. They have clearly a different sound signature from the rest. Have you ever listended to one? If you are going to doubt that, you should do it and otherwise remain silent. If you did, there should be need need to argue about it.

 

[MayaTlab]

I did, with my own eardrum, which stayed basically the same over the years,

How do you know ?

listen to a lot of different headphones, including various Stax models. They have clearly a different sound signature from the rest.

Which could entirely be a question of FR (particularly given that all Lambda style Stax, what you've experienced so far, share some common traits). Or not.
Knowing whether or not that is the case requires the FR variable to be controlled, which unfortunately is quite difficult.

The only somewhat reliable way to do so below threshold of audibility is to record headphones on a dummy head after equalising them on the same dummy head to the same target (without moving them between the measurement + EQ phase and the recording phase, otherwise FR may change).
This is what was done (without the bit in italic though, unfortunately) in this study on the influence of non-linear distortion on preference scores :

AES E-Library » The Correlation between Distortion Audibility and Listener Preference in Headphones

It is well-known that the frequency response of loudspeakers and headphones has a dramatic impact on sound quality and listener preference, but what role does distortion have on perceived sound quality? To answer this question, five popular headphones with varying degrees of distortion were...

www.aes.org

That study notably included the K701 and Stax 009 which scored the same (although I'd posit that in the format of Harman's research, similar score =/= sounds the same, it just means "equally preferred"), and where it seems tests subjects generally had a difficult time to pick headphones appart when tested this way.

Another way is to perform in situ measurements with in-ear mics, but that is not straightforward to do.

What you can't do however, is equalise to the same target your own samples according to third party presets based on other samples, and then presume that the FR variable has been effectively controlled.

Have you ever listended to one? If you are going to doubt that, you should do it and otherwise remain silent. If you did, there should be need need to argue about it.

I've owned one for several years.

 

[vert]

I have a pair of Sigmas which were gifted to me by an older colleague was had a large collection of hi-fi gear from the 80s and 90s. He had two pairs of the Sigmas. They were in as new condition. The quality of the plastics is impressive. I've had a pair of $100 modern IEMs where the plastic gassed out after two years. They have a crackling, like thin torn paper on the left side when just powered on but it goes away after a while. They sound very good, possibly best with classical. They need EQ IMO. I use a ready-made curve which I've modified slightly by ear in the mid bass range. They weigh nothing on the head and can be worn for hours. It's fun to own a little piece of audio fairy land, but I'm not sure I would have gone out of my way to buy them otherwise. They're a technical wonder not a unicorn. They're good enough as to contain most GAS attacks but won't prevent me from buying the Senny HD-600 at some point.

 

[lewis]

Hello fellow headphones (earspeaker) enthusiasts,


After, again, too much time spent on forum and other internet places I can't wrap my head around one issue. So, I reach you, the community that seems to be the most able to answer my question.

Last year I got the opportunity to compare a Stax L300 with an Audeze LCD-X, one white Grado (don't remember the name) and my EQd M1060. A few years prior to that I already could hear a Stax and the LCD-X and didn't like the Stax but loved the LCD so I had little expectations for the Stax.
But surprise, I loved the Stax. Ok the bass don't slam as much as what the Magnetic Planar could do but it had something else. There is some confusion with terms like detailed/clean/clear so I would just say that the Stax seemed more like there was nothing between me and the music. In this regard the LCD seemed barely better than my M1060 I could even be imagining it, but the Stax was definitely better.

So, I want to understand why.

Here a lot of people say that the technology behind doesn't really matter it's the implementation. I also read that the Electrostatic have thinner driver that let them move faster resulting in this effect. Some say that the Abyss can match this effect, but they don't seem to have good measurement to back that up.
Do the Stax have much lower distortion? It's difficult to find measurements of Stax and what I could find do not confirm this. Also, the LCD seems to have low distortion.
The frequency response that's better? I tried later at home to EQ my M1060 to death trying to reproduce what I heard without improvements.
My amp could be the culprit but it's a Drop O2 and the LCD or M1060 are pretty efficient and this amp does a good job as Amirm measurements revealed.

I also have a Shure SRH1840 who does worse than both ortho but this one is well known to have quite a bit of distortion.

Stax RS-L300 and the Stax SRM252S aren't expensive in the scheme of things so why not just buy them and sell the headphones that you don't like as much.

 

[Garrincha]

How do you know ?



Which could entirely be a question of FR (particularly given that all Lambda style Stax, what you've experienced so far, share some common traits). Or not.
Knowing whether or not that is the case requires the FR variable to be controlled, which unfortunately is quite difficult.

The only somewhat reliable way to do so below threshold of audibility is to record headphones on a dummy head after equalising them on the same dummy head to the same target (without moving them between the measurement + EQ phase and the recording phase, otherwise FR may change).
This is what was done (without the bit in italic though, unfortunately) in this study on the influence of non-linear distortion on preference scores :

AES E-Library » The Correlation between Distortion Audibility and Listener Preference in Headphones

It is well-known that the frequency response of loudspeakers and headphones has a dramatic impact on sound quality and listener preference, but what role does distortion have on perceived sound quality? To answer this question, five popular headphones with varying degrees of distortion were...

www.aes.org

That study notably included the K701 and Stax 009 which scored the same (although I'd posit that in the format of Harman's research, similar score =/= sounds the same, it just means "equally preferred"), and where it seems tests subjects generally had a difficult time to pick headphones appart when tested this way.

Another way is to perform in situ measurements with in-ear mics, but that is not straightforward to do.

What you can't do however, is equalise to the same target your own samples according to third party presets based on other samples, and then presume that the FR variable has been effectively controlled.



I've owned one for several years.

Sorry, but your reasoning is very simplistic, if not primitive. If you REALLY want to claim and convince me that besides FR and low distortion&noise there are no other determining parameters of the sound of a headphone, then we don´t need to discuss any further, because I can not take you seriously and consider you as a person with limited listening capabilities. Ever heard of transients, soundstage and imaging? None of these are captured by FR, noise or distortion, but are nevertheless real phenomena. Yeah, and surely the AKG K701 and the Stax SR 009 sound 100% the same, surely, because Olive/Toole say so, sure.

 

[JamesRF]

How do you know ?



Which could entirely be a question of FR (particularly given that all Lambda style Stax, what you've experienced so far, share some common traits). Or not.
Knowing whether or not that is the case requires the FR variable to be controlled, which unfortunately is quite difficult.

The only somewhat reliable way to do so below threshold of audibility is to record headphones on a dummy head after equalising them on the same dummy head to the same target (without moving them between the measurement + EQ phase and the recording phase, otherwise FR may change).
This is what was done (without the bit in italic though, unfortunately) in this study on the influence of non-linear distortion on preference scores :

AES E-Library » The Correlation between Distortion Audibility and Listener Preference in Headphones

It is well-known that the frequency response of loudspeakers and headphones has a dramatic impact on sound quality and listener preference, but what role does distortion have on perceived sound quality? To answer this question, five popular headphones with varying degrees of distortion were...

www.aes.org

That study notably included the K701 and Stax 009 which scored the same (although I'd posit that in the format of Harman's research, similar score =/= sounds the same, it just means "equally preferred"), and where it seems tests subjects generally had a difficult time to pick headphones appart when tested this way.

Another way is to perform in situ measurements with in-ear mics, but that is not straightforward to do.

What you can't do however, is equalise to the same target your own samples according to third party presets based on other samples, and then presume that the FR variable has been effectively controlled.



I've owned one for several years.

I've been in an around playing and recording music for years, and I have no idea what this means! I don't think simplistic quite captures it!! The suggestion that there's some scientific proposition that requires us all to accept that all phones sound the same, or that we can make them sound the same with some judicious eq is ridiculous. The hectoring, self-righteous tone doesn't help. Beware the self-appointed expert!

 

[Garrincha]

I've been in an around playing and recording music for years, and I have no idea what this means! I don't think simplistic quite captures it!! The suggestion that there's some scientific proposition that requires us all to accept that all phones sound the same, or that we can make them sound the same with some judicious eq is ridiculous. The hectoring, self-righteous tone doesn't help. Beware the self-appointed expert!

But how do you know this? There is never the exact same FR at your own eardrum!! I am an eardrum skeptic!! What do we know about the FR at anybodies eardrum?? What do Olive and Toole say about it??? Can I implant Toole´s eardrum to have his listening experience??

 

[Garrincha]

That study notably included the K701 and Stax 009 which scored the same (although I'd posit that in the format of Harman's research, similar score =/= sounds the same, it just means "equally preferred"), and where it seems tests subjects generally had a difficult time to pick headphones appart when tested this way.

Many people like chocolate as much as they like a steak. Do both then taste the same?

 

[jacko]

Does anyone know of any other measurements of Stax besides those seen here: https://www.changstar.com/www.changstar.com/index.php/topic,23.0.html
I am looking at electrostatic technology but in terms of data only I can only find some unique characteristics in transients and CSD (fluttering response per Tyll as quoted on the first page and exceptionally low decay time at high frequency). I am exploring KSE1200 because as an in-ear any confounding effects from ear and cup conformation will be eliminated up to the point of the ear canal.

 

[Zaireeka]

Correct, Stax also used to offer also an (overpriced) diffused field EQ reducing that peak:

View attachment 124647

Interestingly I preferred though my ex entry Lambda (SR-207) sound without it (had the convolution file for it).

I did a pretty accurate emulation of the ED-1 thx to convolution and posted the impulses here: https://www.head-fi.org/threads/stax-ed-1-and-ed-5-eqs-emulation.675545/

I hope the files are still available, if they aren't let me know and I'll re-upload them

 

[Garrincha]

Does anyone know of any other measurements of Stax besides those seen here: https://www.changstar.com/www.changstar.com/index.php/topic,23.0.html
I am looking at electrostatic technology but in terms of data only I can only find some unique characteristics in transients and CSD (fluttering response per Tyll as quoted on the first page and exceptionally low decay time at high frequency). I am exploring KSE1200 because as an in-ear any confounding effects from ear and cup conformation will be eliminated up to the point of the ear canal.

Several Stax headphones are in the list of measured FR curves from oratory1990 on reddit.

 

[chi2]

Does anyone know of any other measurements of Stax besides those seen here: https://www.changstar.com/www.changstar.com/index.php/topic,23.0.html
I am looking at electrostatic technology but in terms of data only I can only find some unique characteristics in transients and CSD (fluttering response per Tyll as quoted on the first page and exceptionally low decay time at high frequency). I am exploring KSE1200 because as an in-ear any confounding effects from ear and cup conformation will be eliminated up to the point of the ear canal.

Sören Schulze has measured almost every Stax phone ever built (https://www.inexxon.com/stax-übersicht-history/). As he used a Neumann K100, the graphs can't be compared 1:1 to measurements done on different rigs [edited]. Still, for the purpose of comparison within his data base, his collection is pretty useful.

 

[Ata]

That is a good resource, thank you.

 

[okok]

no one ever complains about the stax sky high prices, $6600, $7000 cans plus the amp ($3000 or more)???

everything else like a steal