[n3rdling]

Keep in mind doing so alters the strength of the electrostatic force and thus decreases efficiency.

 

[jgazal]

I believe copper surface still remains the same.
 
Nevertheless, the diameter of stator holes is still constrained at the copper face. 
 
I am afraid the "mouth" you propose may reduce the stator rigidity and that could increase distortion.
 
Let’s hear from Wachara.

 

[n3rdling]

You're right, I was reading it upside-down.

 

[peterroumian]

Quote:

I believe copper surface still remains the same.
 
Nevertheless, the diameter of stator holes is still constrained at the copper face. 
 
I am afraid the "mouth" you propose may reduce the stator rigidity and that could increase distortion.
 
Let’s hear from Wachara.

 
i think you are right
 
it was just an idea - like i said "it might improve SQ"

 

[chinsettawong]

Quote:

me too
 
wachara, i had an idea for improving the design of the holes. here it is - tell me what do you think. Left is the "original", right i think might improve air flow. it's important that the copper is untouched because if we go deeper it may start to peal
 
 

Hi Peterroumian,
 
Thanks for sharing your interesting idea.  I really don't know if the shape can improve anything.  You can try though.
 
For what I know, the sound from the diaphragm shoots out like a beam.  It goes in a straight line.  Are you suggesting that by making the holes like that the dispersing of sound will improve?  Why would you want to do that?
 
While we are on this topic, I think there is something that really worth looking into.  As you can notice, the stator of SR007 is partially closed and the open part covered with perforated holes is only 55 mm in diameter out of 78 mm diameter of total copper covered area (active area).  I have been listening to a SR007 MKII against my new Orpheus, and I find that the bass of SR007 is quite punchier.  While mine can go as deep, they just don't sound as punchy as SR007.  I'm not sure if it has anything to do with the stator that is partially closed making the air inside compressed and thus punchier.
 

 
 
 
Wachara C.

 

[arnaud]

Wachara, I had looked at some point at the stiffening effect on the stator when reducing the perforated diameter (stator flexion is a known issue) but I could not see any significant changes in stator mechanical resonances (I posted in this thread some time ago). So, I now wonder about the increased / more homogeneous force on the non-perforated conductive surface which would improve the transduction.

 

[n3rdling]

Is the 007 the only headphone by Stax with such a large non perforated area?

 

[spritzer]

Nope, SR-001 is mostly solid copper with openings just where the went is at the back and the port into the ear.  The intent is clearly improved control via airdamping to get rid of the dreaded HF etch. 

 

[Tjj226 Angel]

Hello,
 
I recently have been trying to get into stax headphones, but let's just say I am not the greatest at winning auctions. I am however good at DIY stuff, and I would like to put together my own headphones. 
 
Before I do that though, I need an amp...otherwise what is the point of making electrostats. 
 
Can someone point me in the direction of a DIY amp for electrostatic headphones? Preferably one that uses tubes? 

 

[jgazal]

Quote:

Wachara, I had looked at some point at the stiffening effect on the stator when reducing the perforated diameter (stator flexion is a known issue) but I could not see any significant changes in stator mechanical resonances (I posted in this thread some time ago). So, I now wonder about the increased / more homogeneous force on the non-perforated conductive surface which would improve the transduction.

 
Does a second completely etched PCB glued to the first PCB improve stiffening?
 
I am imagining both PCB glued to form one stator.
 
Then the transducer would also have that bigger center hole.
 
I have drawn it, but not to scale. First the "color code": 
 

1. "beige" for etched PCB (inactive stator area);
2. "yellow" and "fence texture" for active not perforated and perforate area.

 
Here it is:
 

 
Do you think that center hole is prone to flexion?
 
And here I have another draw from Arnaud idea of different diaphragm masses (in this case three different diaphragms):
 

 
 
Just in case someone finds a way to produce it, here it is another idea. A rounded perforated stator, which I can't even draw correctly. It also has a center ring for two different diaphragms masses:
 

 

 

[Tjj226 Angel]

Here is an idea for you guys. Why not electroplate your PCB in silver. Your headphones will probably be more efficient. 

 

[chinsettawong]

It's fun to have you guys comment on new ideas. 
 
Arnuad, is it possible to do a simulation on the SR007 style stator?  I really wonder if the closed part makes a difference in low frequencies.
 
Tjj226 Angel, I recommended a simple to build tube amp here: http://www.head-fi.org/t/498292/my-diy-electrostatic-headphones#post_6732478
The efficiency of the drivers is greatly dependent on the bias voltage.  The bigger size of the driver helps the sound volume too.
 
Jgazal, I don't think segregating the diaphragm into smaller sections is a good idea.  While the middle circle can indeed produce good treble, the outer bigger circle won't do a good job producing good bass.  Good bass comes from large active area.  By limiting the diaphragm with additional spacers in between might just make the driver becoming a big tweeter.  Well, unless you can make your driver very, very big. 

 
Happy New Year!
 
Wachara C.

 

[Tjj226 Angel]

Quote:

It's fun to have you guys comment on new ideas. 
 
Arnuad, is it possible to do a simulation on the SR007 style stator?  I really wonder if the closed part makes a difference in low frequencies.
 
Tjj226 Angel, I recommended a simple to build tube amp here: http://www.head-fi.org/t/498292/my-diy-electrostatic-headphones#post_6732478
The efficiency of the drivers is greatly dependent on the bias voltage.  The bigger size of the driver helps the sound volume too.
 
Jgazal, I don't think segregating the diaphragm into smaller sections is a good idea.  While the middle circle can indeed produce good treble, the outer bigger circle won't do a good job producing good bass.  Good bass comes from large active area.  By limiting the diaphragm with additional spacers in between might just make the driver becoming a big tweeter.  Well, unless you can make your driver very, very big. 

 
Happy New Year!
 
Wachara C.

 
Yeah, I read that post. But I don't know how to read a circuit map and turn it into a thing. 

 
I was wondering if there was more of a tutorial with pictures. 
 
Edit: Or a good guide on how to read circuit maps because all the guides I find aren't all that great. 

 

[jgazal]

Quote:

It's fun to have you guys comment on new ideas. 
 
(...)
 
Jgazal, I don't think segregating the diaphragm into smaller sections is a good idea.  While the middle circle can indeed produce good treble, the outer bigger circle won't do a good job producing good bass.  Good bass comes from large active area.  By limiting the diaphragm with additional spacers in between might just make the driver becoming a big tweeter.  Well, unless you can make your driver very, very big. 

 
Happy New Year!
 
Wachara C.

 
 
I agree that segregating the diaphragm into three sections is not a good idea. 
 
I was just brain storming...  
 
Anyway, I like the first draw most, since it is feasible with your current techniques.
 
Happy New Year!

 

[n3rdling]

Quote:

Here is an idea for you guys. Why not electroplate your PCB in silver. Your headphones will probably be more efficient. 

 
Silver is only like 6% more conductive than copper IIRC.  I don't think it'd be worth the cost difference.