[edstrelow]

  I'd be curious to hear what knowing the actual thickness of the SR009 diaphragm brings to the table, considering the fact nobody knows what material is actually used 

.
 
A driver is so many more parameters than just the diaphragm thickness, I am not really sure what one thinks can be inferred from knowing this actual property.
 
arnaud

 
All other  things being equal it would be a factor.

 

[arnaud]

In what way does the diaphragm thickness affect the sound in your experience?
Arnaud

 

[richard51]

thickness of the 007 : 1 .35 micron
 
https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.inexxon.com%2Fstax-modelle%2Fstax-kopfh%25C3%25B6rer%2Fsr-007-mk2%2F&edit-text=&act=url
 
thickness of the 009 : probably   around  1 micron  micron

 
https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.inexxon.com%2Fstax-modelle%2Fstax-kopfh%25C3%25B6rer%2Fsr-009%2F&edit-text=&act=url

 

[edstrelow]

In what way does the diaphragm thickness affect the sound in your experience?
Arnaud

 
I think you are mixing up  two different aspects of evaluation,  the evaluation of a physical principle versus the subjective evaluation of a complete product.   
 
As  regards the physics, the less mass there is to move, the more responsive a diaphragm will be.  Surely that is  a given. The ultimate transducer would be the ionophone, which  as I understand it uses a plasma to generate sound.
 
As regards my experience of thick vs thin diaphragms, I would  say that I feel that my older Stax models, eg. SR5, SRXIII pro, and low bias Sigma have  in common the fact of thicker diaphragms than say the SR007 and also have in common a lack of detail compared to the SR007. 
 I have seen but never heard an ionophone speaker so I don't have any relevant experience.  
 
Do I think this is the final say about this issue?  No because there are so many other factors which differentiate on phone from another that it may be wrong to attribute any particular sound quality to one factor alone.  One could of course make a direct comparison of identical phones with diaphragms of different thickness but no-one here is in the position to do that. 
 
I did a comparison like this in the damping thread by comparing different damping materials just by swapping  covers with different damping materials on my SRXIII pro, but that type of experimental manipulation is rare. 

 

[lilbthebasedgod]

Yeah, I'm not saying that the thickness is a huge deal, or the primary reason why an electrostat will sound good or bad, I'm just wondering what exactly is in the 009.  It seems that noone really knows what the new material is and if its better and how thick the diaphragm is.  They seemed to be more transparent in this regard before.

 

[zolkis]

 I have seen but never heard an ionophone speaker so I don't have any relevant experience.  

 
I have heard the plasma/ionic tweeters in Acapella Violin speakers, and I didn't really like them that much as I expected, compared to everyone else seemingly being blown away by them. Surely, the extension, the dynamics was there, but it felt a bit shouty "capacitor-sound" like a hearing aid in normal ears, kind of "too much air", and it's very hard to blend them nicely. There too, it's not enough to have a good principle, the devil is in the details. Perhaps it was the midrange horn blowing it too far, or the tweeters' separate blending controls were set up for people with a hearing loss in the treble, I don't know. I tried to play with them, but didn't manage to find a good setting.
 
Dome tweeters can be nice, with a good polar pattern, but often they lack on dynamics. The famous Scan-Speak Revelator didn't cut it for me until the dome was rebuilt for me by a specialist, with new coatings. Some makers use double tweeters, with good results, but I like more small paper cone dynamic tweeters, albeit they tend to be more directed. It's bearable, good speakers are often like big headphones... (someone said the Dunlavy SC-VI are the world's biggest headphones).
 
As far as treble goes, IMHO nothing gets even reminiscently close to real instruments (especially concerning the dynamic range, and the cleanness and clarity of the harmonic structure) -- of course that also applies to other frequencies, but treble is a beast, especially with such a wide range of tolerance by human hearing. Some get irritated easily, others are more tolerant, but humans in general don't tolerate well bad treble.
 
In headphones, treble is usually bad. They get some aspects right, but it's very hard to make a full-range transducer right so near to the ears in a closed volume. The 009 treble is borderline compromise between extension, smoothness and dynamics; the (modded) 007 has more body and dynamics on the treble but the extension falls off quicker above 10 kHz, resulting in less "air", but also less tendency to break some people's brightness comfort zone (I am fine with the 009). Now it is the relative excess of that "air" that bothered me with the Acapella plasma tweeter. The more important question is to what our brain can adapt better, while preserving the important features of the tonal and dynamic range.

 

[goobicii]

plasma is awesome,problem is the crossover degrades sound,its crossed over very high so the woofer under it is practicaly interfering with the whole range dedicated to that plasma tweeter.Ad to that dac coloring the sound and even the electronics that make the plasma,the room reflections and I am not surprised your experience with plasma was not so good.

 

[goobicii]

correct me if I am wrong but is graphene currently theoreticaly the best material for electrostatic headphones? its only one carbon atom thick,have incredible strenght vs weight ratio and is good conductor

 

[listen4joy]

well, altough i dont hold stax i excited to hear about this new nanotube carboon amp, is it going to relaese this year? is it will be DIY or someone will sell it? is it iwill bring the 009 to new levels after T2 and BHSE?

 

[Michgelsen]

  correct me if I am wrong but is graphene currently theoreticaly the best material for electrostatic headphones? its only one carbon atom thick,have incredible strenght vs weight ratio and is good conductor

 
As electrostatic headphones are manufactured today, the diaphragm needs to be a good insulator, over which a conducting layer is then applied, to form what is essentially a capacitor.

 

[soren_brix]

   
As electrostatic headphones are manufactured today, the diaphragm needs to be a good insulator ...

Why?

 

[jcx]

"constant charge" operation gives the least distortion - to achieve that you want the diaphragm to have a ridiculously high resistance but not be perfectly insulating
 
if the film is lower resistance the charge on the diaphragm can move to the closest point to the stator as the film stretches, giving an extra force term that depends on the signal == distortion
 
good diaphragm plastic films are near perfect insulators as commonly supplied so using what can be easily bought and surface treating it to reach the desired resistance is the economical approach
 
some have speculated that "the best" would be to incorporate just the right amount of "structured carbon" particles in the bulk plastic before forming the film - but there's just not enough demand when even "experimental" batch reactors/mixers for the bulk plastic would make enough film for millions of headphones - and it may take a few tries to hit the exact combo for the final film resistance properties
 
 
with a highly conductive diaphragm it may be possible to predistort the drive V in the amplifier to cancel the moving charge nonlinearity - but its a tough problem open loop, the predistortion parameters likely need to match closer than many headphone drivers are ever made to in serial production in the 1st place - manufacturers brag about better than 1 dB R,L driver matching - and do that by sorting
 
motion feedback adds a lot of complexity too if it could be done at headphone size

 

[rgs9200m]

   
I have heard the plasma/ionic tweeters in Acapella Violin speakers, and I didn't really like them that much as I expected, compared to everyone else seemingly being blown away by them.

Yeah, a few years back I heard those plasma tweeters and I was disappointed (a little tizzy as I recall). Somehow the best tweeter highs in speaker I heard were in Von Schweikert and Dynaudio speakers, especially the big floorstanding ones.
Ribbons are OK, but sometimes the highs in speakers with ribbon tweeters but with conventional drivers for the mids and bass seem to sound like they have a different tonality from the rest of the spectrum, like they don't fit just right.
 
I really like the highs in my SR007 (current version) and my Senn HD650. They are Goldilocks highs and make the whole presentation sound "of a piece" and everything speaks with one voice and nothing stands out artificially.
It's weird that I find myself a fan of these 2 phones and they are sort of favorites overall even though I have heard or owned lots of others, including flagships like the 009 and HD800 and the R10s.
 
Maybe it's because I have owned various SR007s and HD650/600s for over 15 years and they have stood the test of time and I am very used to them and I can't find anything that I can say is absolutely better overall or more musical in every way personally.
(KGSShv mini and Pinnacle amps here.)

 

[zolkis]

 
I really like the highs in my SR007 (current version) and my Senn HD650. They are Goldilocks highs and make the whole presentation sound "of a piece" and everything speaks with one voice and nothing stands out artificially.

 
That! I hear it the same way. Personally I'd include the 009 as well with right amps, especially since it does many things better than the 007 (more neutral to start with, and midrange is more prominent and more linear, resulting in e.g. more faithful piano tonality). The HE1000 would have been also very nice if it had "one voice" over the audio spectrum and wasn't too soft on the attack.
BTW in the HiFi+ guide to headphones I have read today there was an interview with Fang and he said they are working very hard on improving the HE1000.
 
I wonder what Stax is cooking for the successor of the 009, I have the feeling it will be voiced midway between the 007 and 009, but this is pure speculation, and I guess we need to wait a few years for that anyway (allowing time to keep saving money for it .

 

[edstrelow]

   
As far as treble goes, IMHO nothing gets even reminiscently close to real instruments (especially concerning the dynamic range, and the cleanness and clarity of the harmonic structure) -- of course that also applies to other frequencies, but treble is a beast, especially with such a wide range of tolerance by human hearing. Some get irritated easily, others are more tolerant, but humans in general don't tolerate well bad treble.
 
In headphones, treble is usually bad. They get some aspects right, but it's very hard to make a full-range transducer right so near to the ears in a closed volume. The 009 treble is borderline compromise between extension, smoothness and dynamics; the (modded) 007 has more body and dynamics on the treble but the extension falls off quicker above 10 kHz, resulting in less "air", but also less tendency to break some people's brightness comfort zone (I am fine with the 009). Now it is the relative excess of that "air" that bothered me with the Acapella plasma tweeter. The more important question is to what our brain can adapt better, while preserving the important features of the tonal and dynamic range.

 I agree with most of this.   It seemed that when I got into electrostatics headphones and speakers , many years ago the edginess of treble was an issue.  Over the years, I seemed to have been able to tame this beast, and I should add that sorbothane damping has been very effective here.  On the other hand I am also aware that men, in particular, have diminished  high frequency hearing.   It shocked me  a few months ago when I realized that I could no longer hear a 16kHz signal.  That is not unusual.
 
  http://www.roger-russell.com/hearing/hearing.htm#age
 
My wife and kids have always been less enthused about my audio adventures, and I suspect this is partly due to them not liking the treble of many of the phones. I also recall being given a pair of one of the higher end Grados to plug into my display at Canjam in Orange County California and finding them awfully screechy. Yet the guy who gave them to me to listen seemed to think they were something special.  I suspected that he had a serious hearing loss. 
 
Probably no-one should be allowed to comment about high frequency performance without a recent audiogram on file with this site.